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# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Optional
from torch import nn
from .transformer_2d import Transformer2DModel, Transformer2DModelOutput
class DualTransformer2DModel(nn.Module):
"""
Dual transformer wrapper that combines two `Transformer2DModel`s for mixed inference.
Parameters:
num_attention_heads (`int`, *optional*, defaults to 16): The number of heads to use for multi-head attention.
attention_head_dim (`int`, *optional*, defaults to 88): The number of channels in each head.
in_channels (`int`, *optional*):
Pass if the input is continuous. The number of channels in the input and output.
num_layers (`int`, *optional*, defaults to 1): The number of layers of Transformer blocks to use.
dropout (`float`, *optional*, defaults to 0.1): The dropout probability to use.
cross_attention_dim (`int`, *optional*): The number of encoder_hidden_states dimensions to use.
sample_size (`int`, *optional*): Pass if the input is discrete. The width of the latent images.
Note that this is fixed at training time as it is used for learning a number of position embeddings. See
`ImagePositionalEmbeddings`.
num_vector_embeds (`int`, *optional*):
Pass if the input is discrete. The number of classes of the vector embeddings of the latent pixels.
Includes the class for the masked latent pixel.
activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to be used in feed-forward.
num_embeds_ada_norm ( `int`, *optional*): Pass if at least one of the norm_layers is `AdaLayerNorm`.
The number of diffusion steps used during training. Note that this is fixed at training time as it is used
to learn a number of embeddings that are added to the hidden states. During inference, you can denoise for
up to but not more than steps than `num_embeds_ada_norm`.
attention_bias (`bool`, *optional*):
Configure if the TransformerBlocks' attention should contain a bias parameter.
"""
def __init__(
self,
num_attention_heads: int = 16,
attention_head_dim: int = 88,
in_channels: Optional[int] = None,
num_layers: int = 1,
dropout: float = 0.0,
norm_num_groups: int = 32,
cross_attention_dim: Optional[int] = None,
attention_bias: bool = False,
sample_size: Optional[int] = None,
num_vector_embeds: Optional[int] = None,
activation_fn: str = "geglu",
num_embeds_ada_norm: Optional[int] = None,
):
super().__init__()
self.transformers = nn.ModuleList(
[
Transformer2DModel(
num_attention_heads=num_attention_heads,
attention_head_dim=attention_head_dim,
in_channels=in_channels,
num_layers=num_layers,
dropout=dropout,
norm_num_groups=norm_num_groups,
cross_attention_dim=cross_attention_dim,
attention_bias=attention_bias,
sample_size=sample_size,
num_vector_embeds=num_vector_embeds,
activation_fn=activation_fn,
num_embeds_ada_norm=num_embeds_ada_norm,
)
for _ in range(2)
]
)
# Variables that can be set by a pipeline:
# The ratio of transformer1 to transformer2's output states to be combined during inference
self.mix_ratio = 0.5
# The shape of `encoder_hidden_states` is expected to be
# `(batch_size, condition_lengths[0]+condition_lengths[1], num_features)`
self.condition_lengths = [77, 257]
# Which transformer to use to encode which condition.
# E.g. `(1, 0)` means that we'll use `transformers[1](conditions[0])` and `transformers[0](conditions[1])`
self.transformer_index_for_condition = [1, 0]
def forward(
self,
hidden_states,
encoder_hidden_states,
timestep=None,
attention_mask=None,
cross_attention_kwargs=None,
return_dict: bool = True,
):
"""
Args:
hidden_states ( When discrete, `torch.LongTensor` of shape `(batch size, num latent pixels)`.
When continuous, `torch.FloatTensor` of shape `(batch size, channel, height, width)`): Input
hidden_states
encoder_hidden_states ( `torch.LongTensor` of shape `(batch size, encoder_hidden_states dim)`, *optional*):
Conditional embeddings for cross attention layer. If not given, cross-attention defaults to
self-attention.
timestep ( `torch.long`, *optional*):
Optional timestep to be applied as an embedding in AdaLayerNorm's. Used to indicate denoising step.
attention_mask (`torch.FloatTensor`, *optional*):
Optional attention mask to be applied in Attention
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`models.unet_2d_condition.UNet2DConditionOutput`] instead of a plain tuple.
Returns:
[`~models.transformer_2d.Transformer2DModelOutput`] or `tuple`:
[`~models.transformer_2d.Transformer2DModelOutput`] if `return_dict` is True, otherwise a `tuple`. When
returning a tuple, the first element is the sample tensor.
"""
input_states = hidden_states
encoded_states = []
tokens_start = 0
# attention_mask is not used yet
for i in range(2):
# for each of the two transformers, pass the corresponding condition tokens
condition_state = encoder_hidden_states[:, tokens_start : tokens_start + self.condition_lengths[i]]
transformer_index = self.transformer_index_for_condition[i]
encoded_state = self.transformers[transformer_index](
input_states,
encoder_hidden_states=condition_state,
timestep=timestep,
cross_attention_kwargs=cross_attention_kwargs,
return_dict=False,
)[0]
encoded_states.append(encoded_state - input_states)
tokens_start += self.condition_lengths[i]
output_states = encoded_states[0] * self.mix_ratio + encoded_states[1] * (1 - self.mix_ratio)
output_states = output_states + input_states
if not return_dict:
return (output_states,)
return Transformer2DModelOutput(sample=output_states)
| diffusers-main | src/diffusers/models/dual_transformer_2d.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Dict, Optional, Tuple, Union
import torch
import torch.nn as nn
from ..configuration_utils import ConfigMixin, register_to_config
from ..loaders import FromOriginalVAEMixin
from ..utils import BaseOutput
from ..utils.accelerate_utils import apply_forward_hook
from .attention_processor import (
ADDED_KV_ATTENTION_PROCESSORS,
CROSS_ATTENTION_PROCESSORS,
AttentionProcessor,
AttnAddedKVProcessor,
AttnProcessor,
)
from .modeling_utils import ModelMixin
from .vae import Decoder, DecoderOutput, DiagonalGaussianDistribution, Encoder
@dataclass
class AutoencoderKLOutput(BaseOutput):
"""
Output of AutoencoderKL encoding method.
Args:
latent_dist (`DiagonalGaussianDistribution`):
Encoded outputs of `Encoder` represented as the mean and logvar of `DiagonalGaussianDistribution`.
`DiagonalGaussianDistribution` allows for sampling latents from the distribution.
"""
latent_dist: "DiagonalGaussianDistribution"
class AutoencoderKL(ModelMixin, ConfigMixin, FromOriginalVAEMixin):
r"""
A VAE model with KL loss for encoding images into latents and decoding latent representations into images.
This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
for all models (such as downloading or saving).
Parameters:
in_channels (int, *optional*, defaults to 3): Number of channels in the input image.
out_channels (int, *optional*, defaults to 3): Number of channels in the output.
down_block_types (`Tuple[str]`, *optional*, defaults to `("DownEncoderBlock2D",)`):
Tuple of downsample block types.
up_block_types (`Tuple[str]`, *optional*, defaults to `("UpDecoderBlock2D",)`):
Tuple of upsample block types.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(64,)`):
Tuple of block output channels.
act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
latent_channels (`int`, *optional*, defaults to 4): Number of channels in the latent space.
sample_size (`int`, *optional*, defaults to `32`): Sample input size.
scaling_factor (`float`, *optional*, defaults to 0.18215):
The component-wise standard deviation of the trained latent space computed using the first batch of the
training set. This is used to scale the latent space to have unit variance when training the diffusion
model. The latents are scaled with the formula `z = z * scaling_factor` before being passed to the
diffusion model. When decoding, the latents are scaled back to the original scale with the formula: `z = 1
/ scaling_factor * z`. For more details, refer to sections 4.3.2 and D.1 of the [High-Resolution Image
Synthesis with Latent Diffusion Models](https://arxiv.org/abs/2112.10752) paper.
force_upcast (`bool`, *optional*, default to `True`):
If enabled it will force the VAE to run in float32 for high image resolution pipelines, such as SD-XL. VAE
can be fine-tuned / trained to a lower range without loosing too much precision in which case
`force_upcast` can be set to `False` - see: https://huggingface.co/madebyollin/sdxl-vae-fp16-fix
"""
_supports_gradient_checkpointing = True
@register_to_config
def __init__(
self,
in_channels: int = 3,
out_channels: int = 3,
down_block_types: Tuple[str] = ("DownEncoderBlock2D",),
up_block_types: Tuple[str] = ("UpDecoderBlock2D",),
block_out_channels: Tuple[int] = (64,),
layers_per_block: int = 1,
act_fn: str = "silu",
latent_channels: int = 4,
norm_num_groups: int = 32,
sample_size: int = 32,
scaling_factor: float = 0.18215,
force_upcast: float = True,
):
super().__init__()
# pass init params to Encoder
self.encoder = Encoder(
in_channels=in_channels,
out_channels=latent_channels,
down_block_types=down_block_types,
block_out_channels=block_out_channels,
layers_per_block=layers_per_block,
act_fn=act_fn,
norm_num_groups=norm_num_groups,
double_z=True,
)
# pass init params to Decoder
self.decoder = Decoder(
in_channels=latent_channels,
out_channels=out_channels,
up_block_types=up_block_types,
block_out_channels=block_out_channels,
layers_per_block=layers_per_block,
norm_num_groups=norm_num_groups,
act_fn=act_fn,
)
self.quant_conv = nn.Conv2d(2 * latent_channels, 2 * latent_channels, 1)
self.post_quant_conv = nn.Conv2d(latent_channels, latent_channels, 1)
self.use_slicing = False
self.use_tiling = False
# only relevant if vae tiling is enabled
self.tile_sample_min_size = self.config.sample_size
sample_size = (
self.config.sample_size[0]
if isinstance(self.config.sample_size, (list, tuple))
else self.config.sample_size
)
self.tile_latent_min_size = int(sample_size / (2 ** (len(self.config.block_out_channels) - 1)))
self.tile_overlap_factor = 0.25
def _set_gradient_checkpointing(self, module, value=False):
if isinstance(module, (Encoder, Decoder)):
module.gradient_checkpointing = value
def enable_tiling(self, use_tiling: bool = True):
r"""
Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to
compute decoding and encoding in several steps. This is useful for saving a large amount of memory and to allow
processing larger images.
"""
self.use_tiling = use_tiling
def disable_tiling(self):
r"""
Disable tiled VAE decoding. If `enable_tiling` was previously enabled, this method will go back to computing
decoding in one step.
"""
self.enable_tiling(False)
def enable_slicing(self):
r"""
Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to
compute decoding in several steps. This is useful to save some memory and allow larger batch sizes.
"""
self.use_slicing = True
def disable_slicing(self):
r"""
Disable sliced VAE decoding. If `enable_slicing` was previously enabled, this method will go back to computing
decoding in one step.
"""
self.use_slicing = False
@property
# Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.attn_processors
def attn_processors(self) -> Dict[str, AttentionProcessor]:
r"""
Returns:
`dict` of attention processors: A dictionary containing all attention processors used in the model with
indexed by its weight name.
"""
# set recursively
processors = {}
def fn_recursive_add_processors(name: str, module: torch.nn.Module, processors: Dict[str, AttentionProcessor]):
if hasattr(module, "get_processor"):
processors[f"{name}.processor"] = module.get_processor(return_deprecated_lora=True)
for sub_name, child in module.named_children():
fn_recursive_add_processors(f"{name}.{sub_name}", child, processors)
return processors
for name, module in self.named_children():
fn_recursive_add_processors(name, module, processors)
return processors
# Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.set_attn_processor
def set_attn_processor(self, processor: Union[AttentionProcessor, Dict[str, AttentionProcessor]]):
r"""
Sets the attention processor to use to compute attention.
Parameters:
processor (`dict` of `AttentionProcessor` or only `AttentionProcessor`):
The instantiated processor class or a dictionary of processor classes that will be set as the processor
for **all** `Attention` layers.
If `processor` is a dict, the key needs to define the path to the corresponding cross attention
processor. This is strongly recommended when setting trainable attention processors.
"""
count = len(self.attn_processors.keys())
if isinstance(processor, dict) and len(processor) != count:
raise ValueError(
f"A dict of processors was passed, but the number of processors {len(processor)} does not match the"
f" number of attention layers: {count}. Please make sure to pass {count} processor classes."
)
def fn_recursive_attn_processor(name: str, module: torch.nn.Module, processor):
if hasattr(module, "set_processor"):
if not isinstance(processor, dict):
module.set_processor(processor)
else:
module.set_processor(processor.pop(f"{name}.processor"))
for sub_name, child in module.named_children():
fn_recursive_attn_processor(f"{name}.{sub_name}", child, processor)
for name, module in self.named_children():
fn_recursive_attn_processor(name, module, processor)
# Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.set_default_attn_processor
def set_default_attn_processor(self):
"""
Disables custom attention processors and sets the default attention implementation.
"""
if all(proc.__class__ in ADDED_KV_ATTENTION_PROCESSORS for proc in self.attn_processors.values()):
processor = AttnAddedKVProcessor()
elif all(proc.__class__ in CROSS_ATTENTION_PROCESSORS for proc in self.attn_processors.values()):
processor = AttnProcessor()
else:
raise ValueError(
f"Cannot call `set_default_attn_processor` when attention processors are of type {next(iter(self.attn_processors.values()))}"
)
self.set_attn_processor(processor)
@apply_forward_hook
def encode(self, x: torch.FloatTensor, return_dict: bool = True) -> AutoencoderKLOutput:
if self.use_tiling and (x.shape[-1] > self.tile_sample_min_size or x.shape[-2] > self.tile_sample_min_size):
return self.tiled_encode(x, return_dict=return_dict)
if self.use_slicing and x.shape[0] > 1:
encoded_slices = [self.encoder(x_slice) for x_slice in x.split(1)]
h = torch.cat(encoded_slices)
else:
h = self.encoder(x)
moments = self.quant_conv(h)
posterior = DiagonalGaussianDistribution(moments)
if not return_dict:
return (posterior,)
return AutoencoderKLOutput(latent_dist=posterior)
def _decode(self, z: torch.FloatTensor, return_dict: bool = True) -> Union[DecoderOutput, torch.FloatTensor]:
if self.use_tiling and (z.shape[-1] > self.tile_latent_min_size or z.shape[-2] > self.tile_latent_min_size):
return self.tiled_decode(z, return_dict=return_dict)
z = self.post_quant_conv(z)
dec = self.decoder(z)
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
@apply_forward_hook
def decode(self, z: torch.FloatTensor, return_dict: bool = True) -> Union[DecoderOutput, torch.FloatTensor]:
if self.use_slicing and z.shape[0] > 1:
decoded_slices = [self._decode(z_slice).sample for z_slice in z.split(1)]
decoded = torch.cat(decoded_slices)
else:
decoded = self._decode(z).sample
if not return_dict:
return (decoded,)
return DecoderOutput(sample=decoded)
def blend_v(self, a, b, blend_extent):
blend_extent = min(a.shape[2], b.shape[2], blend_extent)
for y in range(blend_extent):
b[:, :, y, :] = a[:, :, -blend_extent + y, :] * (1 - y / blend_extent) + b[:, :, y, :] * (y / blend_extent)
return b
def blend_h(self, a, b, blend_extent):
blend_extent = min(a.shape[3], b.shape[3], blend_extent)
for x in range(blend_extent):
b[:, :, :, x] = a[:, :, :, -blend_extent + x] * (1 - x / blend_extent) + b[:, :, :, x] * (x / blend_extent)
return b
def tiled_encode(self, x: torch.FloatTensor, return_dict: bool = True) -> AutoencoderKLOutput:
r"""Encode a batch of images using a tiled encoder.
When this option is enabled, the VAE will split the input tensor into tiles to compute encoding in several
steps. This is useful to keep memory use constant regardless of image size. The end result of tiled encoding is
different from non-tiled encoding because each tile uses a different encoder. To avoid tiling artifacts, the
tiles overlap and are blended together to form a smooth output. You may still see tile-sized changes in the
output, but they should be much less noticeable.
Args:
x (`torch.FloatTensor`): Input batch of images.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.autoencoder_kl.AutoencoderKLOutput`] instead of a plain tuple.
Returns:
[`~models.autoencoder_kl.AutoencoderKLOutput`] or `tuple`:
If return_dict is True, a [`~models.autoencoder_kl.AutoencoderKLOutput`] is returned, otherwise a plain
`tuple` is returned.
"""
overlap_size = int(self.tile_sample_min_size * (1 - self.tile_overlap_factor))
blend_extent = int(self.tile_latent_min_size * self.tile_overlap_factor)
row_limit = self.tile_latent_min_size - blend_extent
# Split the image into 512x512 tiles and encode them separately.
rows = []
for i in range(0, x.shape[2], overlap_size):
row = []
for j in range(0, x.shape[3], overlap_size):
tile = x[:, :, i : i + self.tile_sample_min_size, j : j + self.tile_sample_min_size]
tile = self.encoder(tile)
tile = self.quant_conv(tile)
row.append(tile)
rows.append(row)
result_rows = []
for i, row in enumerate(rows):
result_row = []
for j, tile in enumerate(row):
# blend the above tile and the left tile
# to the current tile and add the current tile to the result row
if i > 0:
tile = self.blend_v(rows[i - 1][j], tile, blend_extent)
if j > 0:
tile = self.blend_h(row[j - 1], tile, blend_extent)
result_row.append(tile[:, :, :row_limit, :row_limit])
result_rows.append(torch.cat(result_row, dim=3))
moments = torch.cat(result_rows, dim=2)
posterior = DiagonalGaussianDistribution(moments)
if not return_dict:
return (posterior,)
return AutoencoderKLOutput(latent_dist=posterior)
def tiled_decode(self, z: torch.FloatTensor, return_dict: bool = True) -> Union[DecoderOutput, torch.FloatTensor]:
r"""
Decode a batch of images using a tiled decoder.
Args:
z (`torch.FloatTensor`): Input batch of latent vectors.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.
Returns:
[`~models.vae.DecoderOutput`] or `tuple`:
If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
returned.
"""
overlap_size = int(self.tile_latent_min_size * (1 - self.tile_overlap_factor))
blend_extent = int(self.tile_sample_min_size * self.tile_overlap_factor)
row_limit = self.tile_sample_min_size - blend_extent
# Split z into overlapping 64x64 tiles and decode them separately.
# The tiles have an overlap to avoid seams between tiles.
rows = []
for i in range(0, z.shape[2], overlap_size):
row = []
for j in range(0, z.shape[3], overlap_size):
tile = z[:, :, i : i + self.tile_latent_min_size, j : j + self.tile_latent_min_size]
tile = self.post_quant_conv(tile)
decoded = self.decoder(tile)
row.append(decoded)
rows.append(row)
result_rows = []
for i, row in enumerate(rows):
result_row = []
for j, tile in enumerate(row):
# blend the above tile and the left tile
# to the current tile and add the current tile to the result row
if i > 0:
tile = self.blend_v(rows[i - 1][j], tile, blend_extent)
if j > 0:
tile = self.blend_h(row[j - 1], tile, blend_extent)
result_row.append(tile[:, :, :row_limit, :row_limit])
result_rows.append(torch.cat(result_row, dim=3))
dec = torch.cat(result_rows, dim=2)
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
def forward(
self,
sample: torch.FloatTensor,
sample_posterior: bool = False,
return_dict: bool = True,
generator: Optional[torch.Generator] = None,
) -> Union[DecoderOutput, torch.FloatTensor]:
r"""
Args:
sample (`torch.FloatTensor`): Input sample.
sample_posterior (`bool`, *optional*, defaults to `False`):
Whether to sample from the posterior.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`DecoderOutput`] instead of a plain tuple.
"""
x = sample
posterior = self.encode(x).latent_dist
if sample_posterior:
z = posterior.sample(generator=generator)
else:
z = posterior.mode()
dec = self.decode(z).sample
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
| diffusers-main | src/diffusers/models/autoencoder_kl.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional
import torch
from torch import nn
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from .attention import BasicTransformerBlock
from .modeling_utils import ModelMixin
@dataclass
class TransformerTemporalModelOutput(BaseOutput):
"""
The output of [`TransformerTemporalModel`].
Args:
sample (`torch.FloatTensor` of shape `(batch_size x num_frames, num_channels, height, width)`):
The hidden states output conditioned on `encoder_hidden_states` input.
"""
sample: torch.FloatTensor
class TransformerTemporalModel(ModelMixin, ConfigMixin):
"""
A Transformer model for video-like data.
Parameters:
num_attention_heads (`int`, *optional*, defaults to 16): The number of heads to use for multi-head attention.
attention_head_dim (`int`, *optional*, defaults to 88): The number of channels in each head.
in_channels (`int`, *optional*):
The number of channels in the input and output (specify if the input is **continuous**).
num_layers (`int`, *optional*, defaults to 1): The number of layers of Transformer blocks to use.
dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
cross_attention_dim (`int`, *optional*): The number of `encoder_hidden_states` dimensions to use.
sample_size (`int`, *optional*): The width of the latent images (specify if the input is **discrete**).
This is fixed during training since it is used to learn a number of position embeddings.
activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to use in feed-forward.
attention_bias (`bool`, *optional*):
Configure if the `TransformerBlock` attention should contain a bias parameter.
double_self_attention (`bool`, *optional*):
Configure if each `TransformerBlock` should contain two self-attention layers.
"""
@register_to_config
def __init__(
self,
num_attention_heads: int = 16,
attention_head_dim: int = 88,
in_channels: Optional[int] = None,
out_channels: Optional[int] = None,
num_layers: int = 1,
dropout: float = 0.0,
norm_num_groups: int = 32,
cross_attention_dim: Optional[int] = None,
attention_bias: bool = False,
sample_size: Optional[int] = None,
activation_fn: str = "geglu",
norm_elementwise_affine: bool = True,
double_self_attention: bool = True,
):
super().__init__()
self.num_attention_heads = num_attention_heads
self.attention_head_dim = attention_head_dim
inner_dim = num_attention_heads * attention_head_dim
self.in_channels = in_channels
self.norm = torch.nn.GroupNorm(num_groups=norm_num_groups, num_channels=in_channels, eps=1e-6, affine=True)
self.proj_in = nn.Linear(in_channels, inner_dim)
# 3. Define transformers blocks
self.transformer_blocks = nn.ModuleList(
[
BasicTransformerBlock(
inner_dim,
num_attention_heads,
attention_head_dim,
dropout=dropout,
cross_attention_dim=cross_attention_dim,
activation_fn=activation_fn,
attention_bias=attention_bias,
double_self_attention=double_self_attention,
norm_elementwise_affine=norm_elementwise_affine,
)
for d in range(num_layers)
]
)
self.proj_out = nn.Linear(inner_dim, in_channels)
def forward(
self,
hidden_states,
encoder_hidden_states=None,
timestep=None,
class_labels=None,
num_frames=1,
cross_attention_kwargs=None,
return_dict: bool = True,
):
"""
The [`TransformerTemporal`] forward method.
Args:
hidden_states (`torch.LongTensor` of shape `(batch size, num latent pixels)` if discrete, `torch.FloatTensor` of shape `(batch size, channel, height, width)` if continuous):
Input hidden_states.
encoder_hidden_states ( `torch.LongTensor` of shape `(batch size, encoder_hidden_states dim)`, *optional*):
Conditional embeddings for cross attention layer. If not given, cross-attention defaults to
self-attention.
timestep ( `torch.long`, *optional*):
Used to indicate denoising step. Optional timestep to be applied as an embedding in `AdaLayerNorm`.
class_labels ( `torch.LongTensor` of shape `(batch size, num classes)`, *optional*):
Used to indicate class labels conditioning. Optional class labels to be applied as an embedding in
`AdaLayerZeroNorm`.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.unet_2d_condition.UNet2DConditionOutput`] instead of a plain
tuple.
Returns:
[`~models.transformer_temporal.TransformerTemporalModelOutput`] or `tuple`:
If `return_dict` is True, an [`~models.transformer_temporal.TransformerTemporalModelOutput`] is
returned, otherwise a `tuple` where the first element is the sample tensor.
"""
# 1. Input
batch_frames, channel, height, width = hidden_states.shape
batch_size = batch_frames // num_frames
residual = hidden_states
hidden_states = hidden_states[None, :].reshape(batch_size, num_frames, channel, height, width)
hidden_states = hidden_states.permute(0, 2, 1, 3, 4)
hidden_states = self.norm(hidden_states)
hidden_states = hidden_states.permute(0, 3, 4, 2, 1).reshape(batch_size * height * width, num_frames, channel)
hidden_states = self.proj_in(hidden_states)
# 2. Blocks
for block in self.transformer_blocks:
hidden_states = block(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
timestep=timestep,
cross_attention_kwargs=cross_attention_kwargs,
class_labels=class_labels,
)
# 3. Output
hidden_states = self.proj_out(hidden_states)
hidden_states = (
hidden_states[None, None, :]
.reshape(batch_size, height, width, channel, num_frames)
.permute(0, 3, 4, 1, 2)
.contiguous()
)
hidden_states = hidden_states.reshape(batch_frames, channel, height, width)
output = hidden_states + residual
if not return_dict:
return (output,)
return TransformerTemporalModelOutput(sample=output)
| diffusers-main | src/diffusers/models/transformer_temporal.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import TYPE_CHECKING
from ..utils import _LazyModule, is_flax_available, is_torch_available
_import_structure = {}
if is_torch_available():
_import_structure["adapter"] = ["MultiAdapter", "T2IAdapter"]
_import_structure["autoencoder_asym_kl"] = ["AsymmetricAutoencoderKL"]
_import_structure["autoencoder_kl"] = ["AutoencoderKL"]
_import_structure["autoencoder_tiny"] = ["AutoencoderTiny"]
_import_structure["controlnet"] = ["ControlNetModel"]
_import_structure["dual_transformer_2d"] = ["DualTransformer2DModel"]
_import_structure["modeling_utils"] = ["ModelMixin"]
_import_structure["prior_transformer"] = ["PriorTransformer"]
_import_structure["t5_film_transformer"] = ["T5FilmDecoder"]
_import_structure["transformer_2d"] = ["Transformer2DModel"]
_import_structure["transformer_temporal"] = ["TransformerTemporalModel"]
_import_structure["unet_1d"] = ["UNet1DModel"]
_import_structure["unet_2d"] = ["UNet2DModel"]
_import_structure["unet_2d_condition"] = ["UNet2DConditionModel"]
_import_structure["unet_3d_condition"] = ["UNet3DConditionModel"]
_import_structure["vq_model"] = ["VQModel"]
if is_flax_available():
_import_structure["controlnet_flax"] = ["FlaxControlNetModel"]
_import_structure["unet_2d_condition_flax"] = ["FlaxUNet2DConditionModel"]
_import_structure["vae_flax"] = ["FlaxAutoencoderKL"]
if TYPE_CHECKING:
if is_torch_available():
from .adapter import MultiAdapter, T2IAdapter
from .autoencoder_asym_kl import AsymmetricAutoencoderKL
from .autoencoder_kl import AutoencoderKL
from .autoencoder_tiny import AutoencoderTiny
from .controlnet import ControlNetModel
from .dual_transformer_2d import DualTransformer2DModel
from .modeling_utils import ModelMixin
from .prior_transformer import PriorTransformer
from .t5_film_transformer import T5FilmDecoder
from .transformer_2d import Transformer2DModel
from .transformer_temporal import TransformerTemporalModel
from .unet_1d import UNet1DModel
from .unet_2d import UNet2DModel
from .unet_2d_condition import UNet2DConditionModel
from .unet_3d_condition import UNet3DConditionModel
from .vq_model import VQModel
if is_flax_available():
from .controlnet_flax import FlaxControlNetModel
from .unet_2d_condition_flax import FlaxUNet2DConditionModel
from .vae_flax import FlaxAutoencoderKL
else:
import sys
sys.modules[__name__] = _LazyModule(__name__, globals()["__file__"], _import_structure, module_spec=__spec__)
| diffusers-main | src/diffusers/models/__init__.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import flax.linen as nn
import jax
import jax.numpy as jnp
class FlaxUpsample2D(nn.Module):
out_channels: int
dtype: jnp.dtype = jnp.float32
def setup(self):
self.conv = nn.Conv(
self.out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
def __call__(self, hidden_states):
batch, height, width, channels = hidden_states.shape
hidden_states = jax.image.resize(
hidden_states,
shape=(batch, height * 2, width * 2, channels),
method="nearest",
)
hidden_states = self.conv(hidden_states)
return hidden_states
class FlaxDownsample2D(nn.Module):
out_channels: int
dtype: jnp.dtype = jnp.float32
def setup(self):
self.conv = nn.Conv(
self.out_channels,
kernel_size=(3, 3),
strides=(2, 2),
padding=((1, 1), (1, 1)), # padding="VALID",
dtype=self.dtype,
)
def __call__(self, hidden_states):
# pad = ((0, 0), (0, 1), (0, 1), (0, 0)) # pad height and width dim
# hidden_states = jnp.pad(hidden_states, pad_width=pad)
hidden_states = self.conv(hidden_states)
return hidden_states
class FlaxResnetBlock2D(nn.Module):
in_channels: int
out_channels: int = None
dropout_prob: float = 0.0
use_nin_shortcut: bool = None
dtype: jnp.dtype = jnp.float32
def setup(self):
out_channels = self.in_channels if self.out_channels is None else self.out_channels
self.norm1 = nn.GroupNorm(num_groups=32, epsilon=1e-5)
self.conv1 = nn.Conv(
out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
self.time_emb_proj = nn.Dense(out_channels, dtype=self.dtype)
self.norm2 = nn.GroupNorm(num_groups=32, epsilon=1e-5)
self.dropout = nn.Dropout(self.dropout_prob)
self.conv2 = nn.Conv(
out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
use_nin_shortcut = self.in_channels != out_channels if self.use_nin_shortcut is None else self.use_nin_shortcut
self.conv_shortcut = None
if use_nin_shortcut:
self.conv_shortcut = nn.Conv(
out_channels,
kernel_size=(1, 1),
strides=(1, 1),
padding="VALID",
dtype=self.dtype,
)
def __call__(self, hidden_states, temb, deterministic=True):
residual = hidden_states
hidden_states = self.norm1(hidden_states)
hidden_states = nn.swish(hidden_states)
hidden_states = self.conv1(hidden_states)
temb = self.time_emb_proj(nn.swish(temb))
temb = jnp.expand_dims(jnp.expand_dims(temb, 1), 1)
hidden_states = hidden_states + temb
hidden_states = self.norm2(hidden_states)
hidden_states = nn.swish(hidden_states)
hidden_states = self.dropout(hidden_states, deterministic)
hidden_states = self.conv2(hidden_states)
if self.conv_shortcut is not None:
residual = self.conv_shortcut(residual)
return hidden_states + residual
| diffusers-main | src/diffusers/models/resnet_flax.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Optional, Tuple, Union
import flax
import flax.linen as nn
import jax
import jax.numpy as jnp
from flax.core.frozen_dict import FrozenDict
from ..configuration_utils import ConfigMixin, flax_register_to_config
from ..utils import BaseOutput
from .embeddings_flax import FlaxTimestepEmbedding, FlaxTimesteps
from .modeling_flax_utils import FlaxModelMixin
from .unet_2d_blocks_flax import (
FlaxCrossAttnDownBlock2D,
FlaxCrossAttnUpBlock2D,
FlaxDownBlock2D,
FlaxUNetMidBlock2DCrossAttn,
FlaxUpBlock2D,
)
@flax.struct.dataclass
class FlaxUNet2DConditionOutput(BaseOutput):
"""
The output of [`FlaxUNet2DConditionModel`].
Args:
sample (`jnp.ndarray` of shape `(batch_size, num_channels, height, width)`):
The hidden states output conditioned on `encoder_hidden_states` input. Output of last layer of model.
"""
sample: jnp.ndarray
@flax_register_to_config
class FlaxUNet2DConditionModel(nn.Module, FlaxModelMixin, ConfigMixin):
r"""
A conditional 2D UNet model that takes a noisy sample, conditional state, and a timestep and returns a sample
shaped output.
This model inherits from [`FlaxModelMixin`]. Check the superclass documentation for it's generic methods
implemented for all models (such as downloading or saving).
This model is also a Flax Linen [flax.linen.Module](https://flax.readthedocs.io/en/latest/flax.linen.html#module)
subclass. Use it as a regular Flax Linen module and refer to the Flax documentation for all matters related to its
general usage and behavior.
Inherent JAX features such as the following are supported:
- [Just-In-Time (JIT) compilation](https://jax.readthedocs.io/en/latest/jax.html#just-in-time-compilation-jit)
- [Automatic Differentiation](https://jax.readthedocs.io/en/latest/jax.html#automatic-differentiation)
- [Vectorization](https://jax.readthedocs.io/en/latest/jax.html#vectorization-vmap)
- [Parallelization](https://jax.readthedocs.io/en/latest/jax.html#parallelization-pmap)
Parameters:
sample_size (`int`, *optional*):
The size of the input sample.
in_channels (`int`, *optional*, defaults to 4):
The number of channels in the input sample.
out_channels (`int`, *optional*, defaults to 4):
The number of channels in the output.
down_block_types (`Tuple[str]`, *optional*, defaults to `("FlaxCrossAttnDownBlock2D", "FlaxCrossAttnDownBlock2D", "FlaxCrossAttnDownBlock2D", "FlaxDownBlock2D")`):
The tuple of downsample blocks to use.
up_block_types (`Tuple[str]`, *optional*, defaults to `("FlaxUpBlock2D", "FlaxCrossAttnUpBlock2D", "FlaxCrossAttnUpBlock2D", "FlaxCrossAttnUpBlock2D")`):
The tuple of upsample blocks to use.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(320, 640, 1280, 1280)`):
The tuple of output channels for each block.
layers_per_block (`int`, *optional*, defaults to 2):
The number of layers per block.
attention_head_dim (`int` or `Tuple[int]`, *optional*, defaults to 8):
The dimension of the attention heads.
num_attention_heads (`int` or `Tuple[int]`, *optional*):
The number of attention heads.
cross_attention_dim (`int`, *optional*, defaults to 768):
The dimension of the cross attention features.
dropout (`float`, *optional*, defaults to 0):
Dropout probability for down, up and bottleneck blocks.
flip_sin_to_cos (`bool`, *optional*, defaults to `True`):
Whether to flip the sin to cos in the time embedding.
freq_shift (`int`, *optional*, defaults to 0): The frequency shift to apply to the time embedding.
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`):
Enable memory efficient attention as described [here](https://arxiv.org/abs/2112.05682).
"""
sample_size: int = 32
in_channels: int = 4
out_channels: int = 4
down_block_types: Tuple[str] = (
"CrossAttnDownBlock2D",
"CrossAttnDownBlock2D",
"CrossAttnDownBlock2D",
"DownBlock2D",
)
up_block_types: Tuple[str] = ("UpBlock2D", "CrossAttnUpBlock2D", "CrossAttnUpBlock2D", "CrossAttnUpBlock2D")
only_cross_attention: Union[bool, Tuple[bool]] = False
block_out_channels: Tuple[int] = (320, 640, 1280, 1280)
layers_per_block: int = 2
attention_head_dim: Union[int, Tuple[int]] = 8
num_attention_heads: Optional[Union[int, Tuple[int]]] = None
cross_attention_dim: int = 1280
dropout: float = 0.0
use_linear_projection: bool = False
dtype: jnp.dtype = jnp.float32
flip_sin_to_cos: bool = True
freq_shift: int = 0
use_memory_efficient_attention: bool = False
def init_weights(self, rng: jax.random.KeyArray) -> FrozenDict:
# init input tensors
sample_shape = (1, self.in_channels, self.sample_size, self.sample_size)
sample = jnp.zeros(sample_shape, dtype=jnp.float32)
timesteps = jnp.ones((1,), dtype=jnp.int32)
encoder_hidden_states = jnp.zeros((1, 1, self.cross_attention_dim), dtype=jnp.float32)
params_rng, dropout_rng = jax.random.split(rng)
rngs = {"params": params_rng, "dropout": dropout_rng}
return self.init(rngs, sample, timesteps, encoder_hidden_states)["params"]
def setup(self):
block_out_channels = self.block_out_channels
time_embed_dim = block_out_channels[0] * 4
if self.num_attention_heads is not None:
raise ValueError(
"At the moment it is not possible to define the number of attention heads via `num_attention_heads` because of a naming issue as described in https://github.com/huggingface/diffusers/issues/2011#issuecomment-1547958131. Passing `num_attention_heads` will only be supported in diffusers v0.19."
)
# If `num_attention_heads` is not defined (which is the case for most models)
# it will default to `attention_head_dim`. This looks weird upon first reading it and it is.
# The reason for this behavior is to correct for incorrectly named variables that were introduced
# when this library was created. The incorrect naming was only discovered much later in https://github.com/huggingface/diffusers/issues/2011#issuecomment-1547958131
# Changing `attention_head_dim` to `num_attention_heads` for 40,000+ configurations is too backwards breaking
# which is why we correct for the naming here.
num_attention_heads = self.num_attention_heads or self.attention_head_dim
# input
self.conv_in = nn.Conv(
block_out_channels[0],
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
# time
self.time_proj = FlaxTimesteps(
block_out_channels[0], flip_sin_to_cos=self.flip_sin_to_cos, freq_shift=self.config.freq_shift
)
self.time_embedding = FlaxTimestepEmbedding(time_embed_dim, dtype=self.dtype)
only_cross_attention = self.only_cross_attention
if isinstance(only_cross_attention, bool):
only_cross_attention = (only_cross_attention,) * len(self.down_block_types)
if isinstance(num_attention_heads, int):
num_attention_heads = (num_attention_heads,) * len(self.down_block_types)
# down
down_blocks = []
output_channel = block_out_channels[0]
for i, down_block_type in enumerate(self.down_block_types):
input_channel = output_channel
output_channel = block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
if down_block_type == "CrossAttnDownBlock2D":
down_block = FlaxCrossAttnDownBlock2D(
in_channels=input_channel,
out_channels=output_channel,
dropout=self.dropout,
num_layers=self.layers_per_block,
num_attention_heads=num_attention_heads[i],
add_downsample=not is_final_block,
use_linear_projection=self.use_linear_projection,
only_cross_attention=only_cross_attention[i],
use_memory_efficient_attention=self.use_memory_efficient_attention,
dtype=self.dtype,
)
else:
down_block = FlaxDownBlock2D(
in_channels=input_channel,
out_channels=output_channel,
dropout=self.dropout,
num_layers=self.layers_per_block,
add_downsample=not is_final_block,
dtype=self.dtype,
)
down_blocks.append(down_block)
self.down_blocks = down_blocks
# mid
self.mid_block = FlaxUNetMidBlock2DCrossAttn(
in_channels=block_out_channels[-1],
dropout=self.dropout,
num_attention_heads=num_attention_heads[-1],
use_linear_projection=self.use_linear_projection,
use_memory_efficient_attention=self.use_memory_efficient_attention,
dtype=self.dtype,
)
# up
up_blocks = []
reversed_block_out_channels = list(reversed(block_out_channels))
reversed_num_attention_heads = list(reversed(num_attention_heads))
only_cross_attention = list(reversed(only_cross_attention))
output_channel = reversed_block_out_channels[0]
for i, up_block_type in enumerate(self.up_block_types):
prev_output_channel = output_channel
output_channel = reversed_block_out_channels[i]
input_channel = reversed_block_out_channels[min(i + 1, len(block_out_channels) - 1)]
is_final_block = i == len(block_out_channels) - 1
if up_block_type == "CrossAttnUpBlock2D":
up_block = FlaxCrossAttnUpBlock2D(
in_channels=input_channel,
out_channels=output_channel,
prev_output_channel=prev_output_channel,
num_layers=self.layers_per_block + 1,
num_attention_heads=reversed_num_attention_heads[i],
add_upsample=not is_final_block,
dropout=self.dropout,
use_linear_projection=self.use_linear_projection,
only_cross_attention=only_cross_attention[i],
use_memory_efficient_attention=self.use_memory_efficient_attention,
dtype=self.dtype,
)
else:
up_block = FlaxUpBlock2D(
in_channels=input_channel,
out_channels=output_channel,
prev_output_channel=prev_output_channel,
num_layers=self.layers_per_block + 1,
add_upsample=not is_final_block,
dropout=self.dropout,
dtype=self.dtype,
)
up_blocks.append(up_block)
prev_output_channel = output_channel
self.up_blocks = up_blocks
# out
self.conv_norm_out = nn.GroupNorm(num_groups=32, epsilon=1e-5)
self.conv_out = nn.Conv(
self.out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
def __call__(
self,
sample,
timesteps,
encoder_hidden_states,
down_block_additional_residuals=None,
mid_block_additional_residual=None,
return_dict: bool = True,
train: bool = False,
) -> Union[FlaxUNet2DConditionOutput, Tuple]:
r"""
Args:
sample (`jnp.ndarray`): (batch, channel, height, width) noisy inputs tensor
timestep (`jnp.ndarray` or `float` or `int`): timesteps
encoder_hidden_states (`jnp.ndarray`): (batch_size, sequence_length, hidden_size) encoder hidden states
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`models.unet_2d_condition_flax.FlaxUNet2DConditionOutput`] instead of a
plain tuple.
train (`bool`, *optional*, defaults to `False`):
Use deterministic functions and disable dropout when not training.
Returns:
[`~models.unet_2d_condition_flax.FlaxUNet2DConditionOutput`] or `tuple`:
[`~models.unet_2d_condition_flax.FlaxUNet2DConditionOutput`] if `return_dict` is True, otherwise a `tuple`.
When returning a tuple, the first element is the sample tensor.
"""
# 1. time
if not isinstance(timesteps, jnp.ndarray):
timesteps = jnp.array([timesteps], dtype=jnp.int32)
elif isinstance(timesteps, jnp.ndarray) and len(timesteps.shape) == 0:
timesteps = timesteps.astype(dtype=jnp.float32)
timesteps = jnp.expand_dims(timesteps, 0)
t_emb = self.time_proj(timesteps)
t_emb = self.time_embedding(t_emb)
# 2. pre-process
sample = jnp.transpose(sample, (0, 2, 3, 1))
sample = self.conv_in(sample)
# 3. down
down_block_res_samples = (sample,)
for down_block in self.down_blocks:
if isinstance(down_block, FlaxCrossAttnDownBlock2D):
sample, res_samples = down_block(sample, t_emb, encoder_hidden_states, deterministic=not train)
else:
sample, res_samples = down_block(sample, t_emb, deterministic=not train)
down_block_res_samples += res_samples
if down_block_additional_residuals is not None:
new_down_block_res_samples = ()
for down_block_res_sample, down_block_additional_residual in zip(
down_block_res_samples, down_block_additional_residuals
):
down_block_res_sample += down_block_additional_residual
new_down_block_res_samples += (down_block_res_sample,)
down_block_res_samples = new_down_block_res_samples
# 4. mid
sample = self.mid_block(sample, t_emb, encoder_hidden_states, deterministic=not train)
if mid_block_additional_residual is not None:
sample += mid_block_additional_residual
# 5. up
for up_block in self.up_blocks:
res_samples = down_block_res_samples[-(self.layers_per_block + 1) :]
down_block_res_samples = down_block_res_samples[: -(self.layers_per_block + 1)]
if isinstance(up_block, FlaxCrossAttnUpBlock2D):
sample = up_block(
sample,
temb=t_emb,
encoder_hidden_states=encoder_hidden_states,
res_hidden_states_tuple=res_samples,
deterministic=not train,
)
else:
sample = up_block(sample, temb=t_emb, res_hidden_states_tuple=res_samples, deterministic=not train)
# 6. post-process
sample = self.conv_norm_out(sample)
sample = nn.silu(sample)
sample = self.conv_out(sample)
sample = jnp.transpose(sample, (0, 3, 1, 2))
if not return_dict:
return (sample,)
return FlaxUNet2DConditionOutput(sample=sample)
| diffusers-main | src/diffusers/models/unet_2d_condition_flax.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from typing import Optional
import numpy as np
import torch
from torch import nn
from .activations import get_activation
def get_timestep_embedding(
timesteps: torch.Tensor,
embedding_dim: int,
flip_sin_to_cos: bool = False,
downscale_freq_shift: float = 1,
scale: float = 1,
max_period: int = 10000,
):
"""
This matches the implementation in Denoising Diffusion Probabilistic Models: Create sinusoidal timestep embeddings.
:param timesteps: a 1-D Tensor of N indices, one per batch element.
These may be fractional.
:param embedding_dim: the dimension of the output. :param max_period: controls the minimum frequency of the
embeddings. :return: an [N x dim] Tensor of positional embeddings.
"""
assert len(timesteps.shape) == 1, "Timesteps should be a 1d-array"
half_dim = embedding_dim // 2
exponent = -math.log(max_period) * torch.arange(
start=0, end=half_dim, dtype=torch.float32, device=timesteps.device
)
exponent = exponent / (half_dim - downscale_freq_shift)
emb = torch.exp(exponent)
emb = timesteps[:, None].float() * emb[None, :]
# scale embeddings
emb = scale * emb
# concat sine and cosine embeddings
emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=-1)
# flip sine and cosine embeddings
if flip_sin_to_cos:
emb = torch.cat([emb[:, half_dim:], emb[:, :half_dim]], dim=-1)
# zero pad
if embedding_dim % 2 == 1:
emb = torch.nn.functional.pad(emb, (0, 1, 0, 0))
return emb
def get_2d_sincos_pos_embed(embed_dim, grid_size, cls_token=False, extra_tokens=0):
"""
grid_size: int of the grid height and width return: pos_embed: [grid_size*grid_size, embed_dim] or
[1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
"""
grid_h = np.arange(grid_size, dtype=np.float32)
grid_w = np.arange(grid_size, dtype=np.float32)
grid = np.meshgrid(grid_w, grid_h) # here w goes first
grid = np.stack(grid, axis=0)
grid = grid.reshape([2, 1, grid_size, grid_size])
pos_embed = get_2d_sincos_pos_embed_from_grid(embed_dim, grid)
if cls_token and extra_tokens > 0:
pos_embed = np.concatenate([np.zeros([extra_tokens, embed_dim]), pos_embed], axis=0)
return pos_embed
def get_2d_sincos_pos_embed_from_grid(embed_dim, grid):
if embed_dim % 2 != 0:
raise ValueError("embed_dim must be divisible by 2")
# use half of dimensions to encode grid_h
emb_h = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[0]) # (H*W, D/2)
emb_w = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[1]) # (H*W, D/2)
emb = np.concatenate([emb_h, emb_w], axis=1) # (H*W, D)
return emb
def get_1d_sincos_pos_embed_from_grid(embed_dim, pos):
"""
embed_dim: output dimension for each position pos: a list of positions to be encoded: size (M,) out: (M, D)
"""
if embed_dim % 2 != 0:
raise ValueError("embed_dim must be divisible by 2")
omega = np.arange(embed_dim // 2, dtype=np.float64)
omega /= embed_dim / 2.0
omega = 1.0 / 10000**omega # (D/2,)
pos = pos.reshape(-1) # (M,)
out = np.einsum("m,d->md", pos, omega) # (M, D/2), outer product
emb_sin = np.sin(out) # (M, D/2)
emb_cos = np.cos(out) # (M, D/2)
emb = np.concatenate([emb_sin, emb_cos], axis=1) # (M, D)
return emb
class PatchEmbed(nn.Module):
"""2D Image to Patch Embedding"""
def __init__(
self,
height=224,
width=224,
patch_size=16,
in_channels=3,
embed_dim=768,
layer_norm=False,
flatten=True,
bias=True,
):
super().__init__()
num_patches = (height // patch_size) * (width // patch_size)
self.flatten = flatten
self.layer_norm = layer_norm
self.proj = nn.Conv2d(
in_channels, embed_dim, kernel_size=(patch_size, patch_size), stride=patch_size, bias=bias
)
if layer_norm:
self.norm = nn.LayerNorm(embed_dim, elementwise_affine=False, eps=1e-6)
else:
self.norm = None
pos_embed = get_2d_sincos_pos_embed(embed_dim, int(num_patches**0.5))
self.register_buffer("pos_embed", torch.from_numpy(pos_embed).float().unsqueeze(0), persistent=False)
def forward(self, latent):
latent = self.proj(latent)
if self.flatten:
latent = latent.flatten(2).transpose(1, 2) # BCHW -> BNC
if self.layer_norm:
latent = self.norm(latent)
return latent + self.pos_embed
class TimestepEmbedding(nn.Module):
def __init__(
self,
in_channels: int,
time_embed_dim: int,
act_fn: str = "silu",
out_dim: int = None,
post_act_fn: Optional[str] = None,
cond_proj_dim=None,
):
super().__init__()
self.linear_1 = nn.Linear(in_channels, time_embed_dim)
if cond_proj_dim is not None:
self.cond_proj = nn.Linear(cond_proj_dim, in_channels, bias=False)
else:
self.cond_proj = None
self.act = get_activation(act_fn)
if out_dim is not None:
time_embed_dim_out = out_dim
else:
time_embed_dim_out = time_embed_dim
self.linear_2 = nn.Linear(time_embed_dim, time_embed_dim_out)
if post_act_fn is None:
self.post_act = None
else:
self.post_act = get_activation(post_act_fn)
def forward(self, sample, condition=None):
if condition is not None:
sample = sample + self.cond_proj(condition)
sample = self.linear_1(sample)
if self.act is not None:
sample = self.act(sample)
sample = self.linear_2(sample)
if self.post_act is not None:
sample = self.post_act(sample)
return sample
class Timesteps(nn.Module):
def __init__(self, num_channels: int, flip_sin_to_cos: bool, downscale_freq_shift: float):
super().__init__()
self.num_channels = num_channels
self.flip_sin_to_cos = flip_sin_to_cos
self.downscale_freq_shift = downscale_freq_shift
def forward(self, timesteps):
t_emb = get_timestep_embedding(
timesteps,
self.num_channels,
flip_sin_to_cos=self.flip_sin_to_cos,
downscale_freq_shift=self.downscale_freq_shift,
)
return t_emb
class GaussianFourierProjection(nn.Module):
"""Gaussian Fourier embeddings for noise levels."""
def __init__(
self, embedding_size: int = 256, scale: float = 1.0, set_W_to_weight=True, log=True, flip_sin_to_cos=False
):
super().__init__()
self.weight = nn.Parameter(torch.randn(embedding_size) * scale, requires_grad=False)
self.log = log
self.flip_sin_to_cos = flip_sin_to_cos
if set_W_to_weight:
# to delete later
self.W = nn.Parameter(torch.randn(embedding_size) * scale, requires_grad=False)
self.weight = self.W
def forward(self, x):
if self.log:
x = torch.log(x)
x_proj = x[:, None] * self.weight[None, :] * 2 * np.pi
if self.flip_sin_to_cos:
out = torch.cat([torch.cos(x_proj), torch.sin(x_proj)], dim=-1)
else:
out = torch.cat([torch.sin(x_proj), torch.cos(x_proj)], dim=-1)
return out
class ImagePositionalEmbeddings(nn.Module):
"""
Converts latent image classes into vector embeddings. Sums the vector embeddings with positional embeddings for the
height and width of the latent space.
For more details, see figure 10 of the dall-e paper: https://arxiv.org/abs/2102.12092
For VQ-diffusion:
Output vector embeddings are used as input for the transformer.
Note that the vector embeddings for the transformer are different than the vector embeddings from the VQVAE.
Args:
num_embed (`int`):
Number of embeddings for the latent pixels embeddings.
height (`int`):
Height of the latent image i.e. the number of height embeddings.
width (`int`):
Width of the latent image i.e. the number of width embeddings.
embed_dim (`int`):
Dimension of the produced vector embeddings. Used for the latent pixel, height, and width embeddings.
"""
def __init__(
self,
num_embed: int,
height: int,
width: int,
embed_dim: int,
):
super().__init__()
self.height = height
self.width = width
self.num_embed = num_embed
self.embed_dim = embed_dim
self.emb = nn.Embedding(self.num_embed, embed_dim)
self.height_emb = nn.Embedding(self.height, embed_dim)
self.width_emb = nn.Embedding(self.width, embed_dim)
def forward(self, index):
emb = self.emb(index)
height_emb = self.height_emb(torch.arange(self.height, device=index.device).view(1, self.height))
# 1 x H x D -> 1 x H x 1 x D
height_emb = height_emb.unsqueeze(2)
width_emb = self.width_emb(torch.arange(self.width, device=index.device).view(1, self.width))
# 1 x W x D -> 1 x 1 x W x D
width_emb = width_emb.unsqueeze(1)
pos_emb = height_emb + width_emb
# 1 x H x W x D -> 1 x L xD
pos_emb = pos_emb.view(1, self.height * self.width, -1)
emb = emb + pos_emb[:, : emb.shape[1], :]
return emb
class LabelEmbedding(nn.Module):
"""
Embeds class labels into vector representations. Also handles label dropout for classifier-free guidance.
Args:
num_classes (`int`): The number of classes.
hidden_size (`int`): The size of the vector embeddings.
dropout_prob (`float`): The probability of dropping a label.
"""
def __init__(self, num_classes, hidden_size, dropout_prob):
super().__init__()
use_cfg_embedding = dropout_prob > 0
self.embedding_table = nn.Embedding(num_classes + use_cfg_embedding, hidden_size)
self.num_classes = num_classes
self.dropout_prob = dropout_prob
def token_drop(self, labels, force_drop_ids=None):
"""
Drops labels to enable classifier-free guidance.
"""
if force_drop_ids is None:
drop_ids = torch.rand(labels.shape[0], device=labels.device) < self.dropout_prob
else:
drop_ids = torch.tensor(force_drop_ids == 1)
labels = torch.where(drop_ids, self.num_classes, labels)
return labels
def forward(self, labels: torch.LongTensor, force_drop_ids=None):
use_dropout = self.dropout_prob > 0
if (self.training and use_dropout) or (force_drop_ids is not None):
labels = self.token_drop(labels, force_drop_ids)
embeddings = self.embedding_table(labels)
return embeddings
class TextImageProjection(nn.Module):
def __init__(
self,
text_embed_dim: int = 1024,
image_embed_dim: int = 768,
cross_attention_dim: int = 768,
num_image_text_embeds: int = 10,
):
super().__init__()
self.num_image_text_embeds = num_image_text_embeds
self.image_embeds = nn.Linear(image_embed_dim, self.num_image_text_embeds * cross_attention_dim)
self.text_proj = nn.Linear(text_embed_dim, cross_attention_dim)
def forward(self, text_embeds: torch.FloatTensor, image_embeds: torch.FloatTensor):
batch_size = text_embeds.shape[0]
# image
image_text_embeds = self.image_embeds(image_embeds)
image_text_embeds = image_text_embeds.reshape(batch_size, self.num_image_text_embeds, -1)
# text
text_embeds = self.text_proj(text_embeds)
return torch.cat([image_text_embeds, text_embeds], dim=1)
class ImageProjection(nn.Module):
def __init__(
self,
image_embed_dim: int = 768,
cross_attention_dim: int = 768,
num_image_text_embeds: int = 32,
):
super().__init__()
self.num_image_text_embeds = num_image_text_embeds
self.image_embeds = nn.Linear(image_embed_dim, self.num_image_text_embeds * cross_attention_dim)
self.norm = nn.LayerNorm(cross_attention_dim)
def forward(self, image_embeds: torch.FloatTensor):
batch_size = image_embeds.shape[0]
# image
image_embeds = self.image_embeds(image_embeds)
image_embeds = image_embeds.reshape(batch_size, self.num_image_text_embeds, -1)
image_embeds = self.norm(image_embeds)
return image_embeds
class CombinedTimestepLabelEmbeddings(nn.Module):
def __init__(self, num_classes, embedding_dim, class_dropout_prob=0.1):
super().__init__()
self.time_proj = Timesteps(num_channels=256, flip_sin_to_cos=True, downscale_freq_shift=1)
self.timestep_embedder = TimestepEmbedding(in_channels=256, time_embed_dim=embedding_dim)
self.class_embedder = LabelEmbedding(num_classes, embedding_dim, class_dropout_prob)
def forward(self, timestep, class_labels, hidden_dtype=None):
timesteps_proj = self.time_proj(timestep)
timesteps_emb = self.timestep_embedder(timesteps_proj.to(dtype=hidden_dtype)) # (N, D)
class_labels = self.class_embedder(class_labels) # (N, D)
conditioning = timesteps_emb + class_labels # (N, D)
return conditioning
class TextTimeEmbedding(nn.Module):
def __init__(self, encoder_dim: int, time_embed_dim: int, num_heads: int = 64):
super().__init__()
self.norm1 = nn.LayerNorm(encoder_dim)
self.pool = AttentionPooling(num_heads, encoder_dim)
self.proj = nn.Linear(encoder_dim, time_embed_dim)
self.norm2 = nn.LayerNorm(time_embed_dim)
def forward(self, hidden_states):
hidden_states = self.norm1(hidden_states)
hidden_states = self.pool(hidden_states)
hidden_states = self.proj(hidden_states)
hidden_states = self.norm2(hidden_states)
return hidden_states
class TextImageTimeEmbedding(nn.Module):
def __init__(self, text_embed_dim: int = 768, image_embed_dim: int = 768, time_embed_dim: int = 1536):
super().__init__()
self.text_proj = nn.Linear(text_embed_dim, time_embed_dim)
self.text_norm = nn.LayerNorm(time_embed_dim)
self.image_proj = nn.Linear(image_embed_dim, time_embed_dim)
def forward(self, text_embeds: torch.FloatTensor, image_embeds: torch.FloatTensor):
# text
time_text_embeds = self.text_proj(text_embeds)
time_text_embeds = self.text_norm(time_text_embeds)
# image
time_image_embeds = self.image_proj(image_embeds)
return time_image_embeds + time_text_embeds
class ImageTimeEmbedding(nn.Module):
def __init__(self, image_embed_dim: int = 768, time_embed_dim: int = 1536):
super().__init__()
self.image_proj = nn.Linear(image_embed_dim, time_embed_dim)
self.image_norm = nn.LayerNorm(time_embed_dim)
def forward(self, image_embeds: torch.FloatTensor):
# image
time_image_embeds = self.image_proj(image_embeds)
time_image_embeds = self.image_norm(time_image_embeds)
return time_image_embeds
class ImageHintTimeEmbedding(nn.Module):
def __init__(self, image_embed_dim: int = 768, time_embed_dim: int = 1536):
super().__init__()
self.image_proj = nn.Linear(image_embed_dim, time_embed_dim)
self.image_norm = nn.LayerNorm(time_embed_dim)
self.input_hint_block = nn.Sequential(
nn.Conv2d(3, 16, 3, padding=1),
nn.SiLU(),
nn.Conv2d(16, 16, 3, padding=1),
nn.SiLU(),
nn.Conv2d(16, 32, 3, padding=1, stride=2),
nn.SiLU(),
nn.Conv2d(32, 32, 3, padding=1),
nn.SiLU(),
nn.Conv2d(32, 96, 3, padding=1, stride=2),
nn.SiLU(),
nn.Conv2d(96, 96, 3, padding=1),
nn.SiLU(),
nn.Conv2d(96, 256, 3, padding=1, stride=2),
nn.SiLU(),
nn.Conv2d(256, 4, 3, padding=1),
)
def forward(self, image_embeds: torch.FloatTensor, hint: torch.FloatTensor):
# image
time_image_embeds = self.image_proj(image_embeds)
time_image_embeds = self.image_norm(time_image_embeds)
hint = self.input_hint_block(hint)
return time_image_embeds, hint
class AttentionPooling(nn.Module):
# Copied from https://github.com/deep-floyd/IF/blob/2f91391f27dd3c468bf174be5805b4cc92980c0b/deepfloyd_if/model/nn.py#L54
def __init__(self, num_heads, embed_dim, dtype=None):
super().__init__()
self.dtype = dtype
self.positional_embedding = nn.Parameter(torch.randn(1, embed_dim) / embed_dim**0.5)
self.k_proj = nn.Linear(embed_dim, embed_dim, dtype=self.dtype)
self.q_proj = nn.Linear(embed_dim, embed_dim, dtype=self.dtype)
self.v_proj = nn.Linear(embed_dim, embed_dim, dtype=self.dtype)
self.num_heads = num_heads
self.dim_per_head = embed_dim // self.num_heads
def forward(self, x):
bs, length, width = x.size()
def shape(x):
# (bs, length, width) --> (bs, length, n_heads, dim_per_head)
x = x.view(bs, -1, self.num_heads, self.dim_per_head)
# (bs, length, n_heads, dim_per_head) --> (bs, n_heads, length, dim_per_head)
x = x.transpose(1, 2)
# (bs, n_heads, length, dim_per_head) --> (bs*n_heads, length, dim_per_head)
x = x.reshape(bs * self.num_heads, -1, self.dim_per_head)
# (bs*n_heads, length, dim_per_head) --> (bs*n_heads, dim_per_head, length)
x = x.transpose(1, 2)
return x
class_token = x.mean(dim=1, keepdim=True) + self.positional_embedding.to(x.dtype)
x = torch.cat([class_token, x], dim=1) # (bs, length+1, width)
# (bs*n_heads, class_token_length, dim_per_head)
q = shape(self.q_proj(class_token))
# (bs*n_heads, length+class_token_length, dim_per_head)
k = shape(self.k_proj(x))
v = shape(self.v_proj(x))
# (bs*n_heads, class_token_length, length+class_token_length):
scale = 1 / math.sqrt(math.sqrt(self.dim_per_head))
weight = torch.einsum("bct,bcs->bts", q * scale, k * scale) # More stable with f16 than dividing afterwards
weight = torch.softmax(weight.float(), dim=-1).type(weight.dtype)
# (bs*n_heads, dim_per_head, class_token_length)
a = torch.einsum("bts,bcs->bct", weight, v)
# (bs, length+1, width)
a = a.reshape(bs, -1, 1).transpose(1, 2)
return a[:, 0, :] # cls_token
class FourierEmbedder(nn.Module):
def __init__(self, num_freqs=64, temperature=100):
super().__init__()
self.num_freqs = num_freqs
self.temperature = temperature
freq_bands = temperature ** (torch.arange(num_freqs) / num_freqs)
freq_bands = freq_bands[None, None, None]
self.register_buffer("freq_bands", freq_bands, persistent=False)
def __call__(self, x):
x = self.freq_bands * x.unsqueeze(-1)
return torch.stack((x.sin(), x.cos()), dim=-1).permute(0, 1, 3, 4, 2).reshape(*x.shape[:2], -1)
class PositionNet(nn.Module):
def __init__(self, positive_len, out_dim, feature_type="text-only", fourier_freqs=8):
super().__init__()
self.positive_len = positive_len
self.out_dim = out_dim
self.fourier_embedder = FourierEmbedder(num_freqs=fourier_freqs)
self.position_dim = fourier_freqs * 2 * 4 # 2: sin/cos, 4: xyxy
if isinstance(out_dim, tuple):
out_dim = out_dim[0]
if feature_type == "text-only":
self.linears = nn.Sequential(
nn.Linear(self.positive_len + self.position_dim, 512),
nn.SiLU(),
nn.Linear(512, 512),
nn.SiLU(),
nn.Linear(512, out_dim),
)
self.null_positive_feature = torch.nn.Parameter(torch.zeros([self.positive_len]))
elif feature_type == "text-image":
self.linears_text = nn.Sequential(
nn.Linear(self.positive_len + self.position_dim, 512),
nn.SiLU(),
nn.Linear(512, 512),
nn.SiLU(),
nn.Linear(512, out_dim),
)
self.linears_image = nn.Sequential(
nn.Linear(self.positive_len + self.position_dim, 512),
nn.SiLU(),
nn.Linear(512, 512),
nn.SiLU(),
nn.Linear(512, out_dim),
)
self.null_text_feature = torch.nn.Parameter(torch.zeros([self.positive_len]))
self.null_image_feature = torch.nn.Parameter(torch.zeros([self.positive_len]))
self.null_position_feature = torch.nn.Parameter(torch.zeros([self.position_dim]))
def forward(
self,
boxes,
masks,
positive_embeddings=None,
phrases_masks=None,
image_masks=None,
phrases_embeddings=None,
image_embeddings=None,
):
masks = masks.unsqueeze(-1)
# embedding position (it may includes padding as placeholder)
xyxy_embedding = self.fourier_embedder(boxes) # B*N*4 -> B*N*C
# learnable null embedding
xyxy_null = self.null_position_feature.view(1, 1, -1)
# replace padding with learnable null embedding
xyxy_embedding = xyxy_embedding * masks + (1 - masks) * xyxy_null
# positionet with text only information
if positive_embeddings is not None:
# learnable null embedding
positive_null = self.null_positive_feature.view(1, 1, -1)
# replace padding with learnable null embedding
positive_embeddings = positive_embeddings * masks + (1 - masks) * positive_null
objs = self.linears(torch.cat([positive_embeddings, xyxy_embedding], dim=-1))
# positionet with text and image infomation
else:
phrases_masks = phrases_masks.unsqueeze(-1)
image_masks = image_masks.unsqueeze(-1)
# learnable null embedding
text_null = self.null_text_feature.view(1, 1, -1)
image_null = self.null_image_feature.view(1, 1, -1)
# replace padding with learnable null embedding
phrases_embeddings = phrases_embeddings * phrases_masks + (1 - phrases_masks) * text_null
image_embeddings = image_embeddings * image_masks + (1 - image_masks) * image_null
objs_text = self.linears_text(torch.cat([phrases_embeddings, xyxy_embedding], dim=-1))
objs_image = self.linears_image(torch.cat([image_embeddings, xyxy_embedding], dim=-1))
objs = torch.cat([objs_text, objs_image], dim=1)
return objs
| diffusers-main | src/diffusers/models/embeddings.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
import torch
from torch import nn
from ..configuration_utils import ConfigMixin, register_to_config
from .attention_processor import Attention
from .embeddings import get_timestep_embedding
from .modeling_utils import ModelMixin
class T5FilmDecoder(ModelMixin, ConfigMixin):
@register_to_config
def __init__(
self,
input_dims: int = 128,
targets_length: int = 256,
max_decoder_noise_time: float = 2000.0,
d_model: int = 768,
num_layers: int = 12,
num_heads: int = 12,
d_kv: int = 64,
d_ff: int = 2048,
dropout_rate: float = 0.1,
):
super().__init__()
self.conditioning_emb = nn.Sequential(
nn.Linear(d_model, d_model * 4, bias=False),
nn.SiLU(),
nn.Linear(d_model * 4, d_model * 4, bias=False),
nn.SiLU(),
)
self.position_encoding = nn.Embedding(targets_length, d_model)
self.position_encoding.weight.requires_grad = False
self.continuous_inputs_projection = nn.Linear(input_dims, d_model, bias=False)
self.dropout = nn.Dropout(p=dropout_rate)
self.decoders = nn.ModuleList()
for lyr_num in range(num_layers):
# FiLM conditional T5 decoder
lyr = DecoderLayer(d_model=d_model, d_kv=d_kv, num_heads=num_heads, d_ff=d_ff, dropout_rate=dropout_rate)
self.decoders.append(lyr)
self.decoder_norm = T5LayerNorm(d_model)
self.post_dropout = nn.Dropout(p=dropout_rate)
self.spec_out = nn.Linear(d_model, input_dims, bias=False)
def encoder_decoder_mask(self, query_input, key_input):
mask = torch.mul(query_input.unsqueeze(-1), key_input.unsqueeze(-2))
return mask.unsqueeze(-3)
def forward(self, encodings_and_masks, decoder_input_tokens, decoder_noise_time):
batch, _, _ = decoder_input_tokens.shape
assert decoder_noise_time.shape == (batch,)
# decoder_noise_time is in [0, 1), so rescale to expected timing range.
time_steps = get_timestep_embedding(
decoder_noise_time * self.config.max_decoder_noise_time,
embedding_dim=self.config.d_model,
max_period=self.config.max_decoder_noise_time,
).to(dtype=self.dtype)
conditioning_emb = self.conditioning_emb(time_steps).unsqueeze(1)
assert conditioning_emb.shape == (batch, 1, self.config.d_model * 4)
seq_length = decoder_input_tokens.shape[1]
# If we want to use relative positions for audio context, we can just offset
# this sequence by the length of encodings_and_masks.
decoder_positions = torch.broadcast_to(
torch.arange(seq_length, device=decoder_input_tokens.device),
(batch, seq_length),
)
position_encodings = self.position_encoding(decoder_positions)
inputs = self.continuous_inputs_projection(decoder_input_tokens)
inputs += position_encodings
y = self.dropout(inputs)
# decoder: No padding present.
decoder_mask = torch.ones(
decoder_input_tokens.shape[:2], device=decoder_input_tokens.device, dtype=inputs.dtype
)
# Translate encoding masks to encoder-decoder masks.
encodings_and_encdec_masks = [(x, self.encoder_decoder_mask(decoder_mask, y)) for x, y in encodings_and_masks]
# cross attend style: concat encodings
encoded = torch.cat([x[0] for x in encodings_and_encdec_masks], dim=1)
encoder_decoder_mask = torch.cat([x[1] for x in encodings_and_encdec_masks], dim=-1)
for lyr in self.decoders:
y = lyr(
y,
conditioning_emb=conditioning_emb,
encoder_hidden_states=encoded,
encoder_attention_mask=encoder_decoder_mask,
)[0]
y = self.decoder_norm(y)
y = self.post_dropout(y)
spec_out = self.spec_out(y)
return spec_out
class DecoderLayer(nn.Module):
def __init__(self, d_model, d_kv, num_heads, d_ff, dropout_rate, layer_norm_epsilon=1e-6):
super().__init__()
self.layer = nn.ModuleList()
# cond self attention: layer 0
self.layer.append(
T5LayerSelfAttentionCond(d_model=d_model, d_kv=d_kv, num_heads=num_heads, dropout_rate=dropout_rate)
)
# cross attention: layer 1
self.layer.append(
T5LayerCrossAttention(
d_model=d_model,
d_kv=d_kv,
num_heads=num_heads,
dropout_rate=dropout_rate,
layer_norm_epsilon=layer_norm_epsilon,
)
)
# Film Cond MLP + dropout: last layer
self.layer.append(
T5LayerFFCond(d_model=d_model, d_ff=d_ff, dropout_rate=dropout_rate, layer_norm_epsilon=layer_norm_epsilon)
)
def forward(
self,
hidden_states,
conditioning_emb=None,
attention_mask=None,
encoder_hidden_states=None,
encoder_attention_mask=None,
encoder_decoder_position_bias=None,
):
hidden_states = self.layer[0](
hidden_states,
conditioning_emb=conditioning_emb,
attention_mask=attention_mask,
)
if encoder_hidden_states is not None:
encoder_extended_attention_mask = torch.where(encoder_attention_mask > 0, 0, -1e10).to(
encoder_hidden_states.dtype
)
hidden_states = self.layer[1](
hidden_states,
key_value_states=encoder_hidden_states,
attention_mask=encoder_extended_attention_mask,
)
# Apply Film Conditional Feed Forward layer
hidden_states = self.layer[-1](hidden_states, conditioning_emb)
return (hidden_states,)
class T5LayerSelfAttentionCond(nn.Module):
def __init__(self, d_model, d_kv, num_heads, dropout_rate):
super().__init__()
self.layer_norm = T5LayerNorm(d_model)
self.FiLMLayer = T5FiLMLayer(in_features=d_model * 4, out_features=d_model)
self.attention = Attention(query_dim=d_model, heads=num_heads, dim_head=d_kv, out_bias=False, scale_qk=False)
self.dropout = nn.Dropout(dropout_rate)
def forward(
self,
hidden_states,
conditioning_emb=None,
attention_mask=None,
):
# pre_self_attention_layer_norm
normed_hidden_states = self.layer_norm(hidden_states)
if conditioning_emb is not None:
normed_hidden_states = self.FiLMLayer(normed_hidden_states, conditioning_emb)
# Self-attention block
attention_output = self.attention(normed_hidden_states)
hidden_states = hidden_states + self.dropout(attention_output)
return hidden_states
class T5LayerCrossAttention(nn.Module):
def __init__(self, d_model, d_kv, num_heads, dropout_rate, layer_norm_epsilon):
super().__init__()
self.attention = Attention(query_dim=d_model, heads=num_heads, dim_head=d_kv, out_bias=False, scale_qk=False)
self.layer_norm = T5LayerNorm(d_model, eps=layer_norm_epsilon)
self.dropout = nn.Dropout(dropout_rate)
def forward(
self,
hidden_states,
key_value_states=None,
attention_mask=None,
):
normed_hidden_states = self.layer_norm(hidden_states)
attention_output = self.attention(
normed_hidden_states,
encoder_hidden_states=key_value_states,
attention_mask=attention_mask.squeeze(1),
)
layer_output = hidden_states + self.dropout(attention_output)
return layer_output
class T5LayerFFCond(nn.Module):
def __init__(self, d_model, d_ff, dropout_rate, layer_norm_epsilon):
super().__init__()
self.DenseReluDense = T5DenseGatedActDense(d_model=d_model, d_ff=d_ff, dropout_rate=dropout_rate)
self.film = T5FiLMLayer(in_features=d_model * 4, out_features=d_model)
self.layer_norm = T5LayerNorm(d_model, eps=layer_norm_epsilon)
self.dropout = nn.Dropout(dropout_rate)
def forward(self, hidden_states, conditioning_emb=None):
forwarded_states = self.layer_norm(hidden_states)
if conditioning_emb is not None:
forwarded_states = self.film(forwarded_states, conditioning_emb)
forwarded_states = self.DenseReluDense(forwarded_states)
hidden_states = hidden_states + self.dropout(forwarded_states)
return hidden_states
class T5DenseGatedActDense(nn.Module):
def __init__(self, d_model, d_ff, dropout_rate):
super().__init__()
self.wi_0 = nn.Linear(d_model, d_ff, bias=False)
self.wi_1 = nn.Linear(d_model, d_ff, bias=False)
self.wo = nn.Linear(d_ff, d_model, bias=False)
self.dropout = nn.Dropout(dropout_rate)
self.act = NewGELUActivation()
def forward(self, hidden_states):
hidden_gelu = self.act(self.wi_0(hidden_states))
hidden_linear = self.wi_1(hidden_states)
hidden_states = hidden_gelu * hidden_linear
hidden_states = self.dropout(hidden_states)
hidden_states = self.wo(hidden_states)
return hidden_states
class T5LayerNorm(nn.Module):
def __init__(self, hidden_size, eps=1e-6):
"""
Construct a layernorm module in the T5 style. No bias and no subtraction of mean.
"""
super().__init__()
self.weight = nn.Parameter(torch.ones(hidden_size))
self.variance_epsilon = eps
def forward(self, hidden_states):
# T5 uses a layer_norm which only scales and doesn't shift, which is also known as Root Mean
# Square Layer Normalization https://arxiv.org/abs/1910.07467 thus variance is calculated
# w/o mean and there is no bias. Additionally we want to make sure that the accumulation for
# half-precision inputs is done in fp32
variance = hidden_states.to(torch.float32).pow(2).mean(-1, keepdim=True)
hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)
# convert into half-precision if necessary
if self.weight.dtype in [torch.float16, torch.bfloat16]:
hidden_states = hidden_states.to(self.weight.dtype)
return self.weight * hidden_states
class NewGELUActivation(nn.Module):
"""
Implementation of the GELU activation function currently in Google BERT repo (identical to OpenAI GPT). Also see
the Gaussian Error Linear Units paper: https://arxiv.org/abs/1606.08415
"""
def forward(self, input: torch.Tensor) -> torch.Tensor:
return 0.5 * input * (1.0 + torch.tanh(math.sqrt(2.0 / math.pi) * (input + 0.044715 * torch.pow(input, 3.0))))
class T5FiLMLayer(nn.Module):
"""
FiLM Layer
"""
def __init__(self, in_features, out_features):
super().__init__()
self.scale_bias = nn.Linear(in_features, out_features * 2, bias=False)
def forward(self, x, conditioning_emb):
emb = self.scale_bias(conditioning_emb)
scale, shift = torch.chunk(emb, 2, -1)
x = x * (1 + scale) + shift
return x
| diffusers-main | src/diffusers/models/t5_film_transformer.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
# `TemporalConvLayer` Copyright 2023 Alibaba DAMO-VILAB, The ModelScope Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from functools import partial
from typing import Optional
import torch
import torch.nn as nn
import torch.nn.functional as F
from .activations import get_activation
from .attention import AdaGroupNorm
from .attention_processor import SpatialNorm
from .lora import LoRACompatibleConv, LoRACompatibleLinear
class Upsample1D(nn.Module):
"""A 1D upsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
use_conv_transpose (`bool`, default `False`):
option to use a convolution transpose.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
"""
def __init__(self, channels, use_conv=False, use_conv_transpose=False, out_channels=None, name="conv"):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.use_conv_transpose = use_conv_transpose
self.name = name
self.conv = None
if use_conv_transpose:
self.conv = nn.ConvTranspose1d(channels, self.out_channels, 4, 2, 1)
elif use_conv:
self.conv = nn.Conv1d(self.channels, self.out_channels, 3, padding=1)
def forward(self, inputs):
assert inputs.shape[1] == self.channels
if self.use_conv_transpose:
return self.conv(inputs)
outputs = F.interpolate(inputs, scale_factor=2.0, mode="nearest")
if self.use_conv:
outputs = self.conv(outputs)
return outputs
class Downsample1D(nn.Module):
"""A 1D downsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
padding (`int`, default `1`):
padding for the convolution.
"""
def __init__(self, channels, use_conv=False, out_channels=None, padding=1, name="conv"):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.padding = padding
stride = 2
self.name = name
if use_conv:
self.conv = nn.Conv1d(self.channels, self.out_channels, 3, stride=stride, padding=padding)
else:
assert self.channels == self.out_channels
self.conv = nn.AvgPool1d(kernel_size=stride, stride=stride)
def forward(self, inputs):
assert inputs.shape[1] == self.channels
return self.conv(inputs)
class Upsample2D(nn.Module):
"""A 2D upsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
use_conv_transpose (`bool`, default `False`):
option to use a convolution transpose.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
"""
def __init__(self, channels, use_conv=False, use_conv_transpose=False, out_channels=None, name="conv"):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.use_conv_transpose = use_conv_transpose
self.name = name
conv = None
if use_conv_transpose:
conv = nn.ConvTranspose2d(channels, self.out_channels, 4, 2, 1)
elif use_conv:
conv = LoRACompatibleConv(self.channels, self.out_channels, 3, padding=1)
# TODO(Suraj, Patrick) - clean up after weight dicts are correctly renamed
if name == "conv":
self.conv = conv
else:
self.Conv2d_0 = conv
def forward(self, hidden_states, output_size=None, scale: float = 1.0):
assert hidden_states.shape[1] == self.channels
if self.use_conv_transpose:
return self.conv(hidden_states)
# Cast to float32 to as 'upsample_nearest2d_out_frame' op does not support bfloat16
# TODO(Suraj): Remove this cast once the issue is fixed in PyTorch
# https://github.com/pytorch/pytorch/issues/86679
dtype = hidden_states.dtype
if dtype == torch.bfloat16:
hidden_states = hidden_states.to(torch.float32)
# upsample_nearest_nhwc fails with large batch sizes. see https://github.com/huggingface/diffusers/issues/984
if hidden_states.shape[0] >= 64:
hidden_states = hidden_states.contiguous()
# if `output_size` is passed we force the interpolation output
# size and do not make use of `scale_factor=2`
if output_size is None:
hidden_states = F.interpolate(hidden_states, scale_factor=2.0, mode="nearest")
else:
hidden_states = F.interpolate(hidden_states, size=output_size, mode="nearest")
# If the input is bfloat16, we cast back to bfloat16
if dtype == torch.bfloat16:
hidden_states = hidden_states.to(dtype)
# TODO(Suraj, Patrick) - clean up after weight dicts are correctly renamed
if self.use_conv:
if self.name == "conv":
if isinstance(self.conv, LoRACompatibleConv):
hidden_states = self.conv(hidden_states, scale)
else:
hidden_states = self.conv(hidden_states)
else:
if isinstance(self.Conv2d_0, LoRACompatibleConv):
hidden_states = self.Conv2d_0(hidden_states, scale)
else:
hidden_states = self.Conv2d_0(hidden_states)
return hidden_states
class Downsample2D(nn.Module):
"""A 2D downsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
padding (`int`, default `1`):
padding for the convolution.
"""
def __init__(self, channels, use_conv=False, out_channels=None, padding=1, name="conv"):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.padding = padding
stride = 2
self.name = name
if use_conv:
conv = LoRACompatibleConv(self.channels, self.out_channels, 3, stride=stride, padding=padding)
else:
assert self.channels == self.out_channels
conv = nn.AvgPool2d(kernel_size=stride, stride=stride)
# TODO(Suraj, Patrick) - clean up after weight dicts are correctly renamed
if name == "conv":
self.Conv2d_0 = conv
self.conv = conv
elif name == "Conv2d_0":
self.conv = conv
else:
self.conv = conv
def forward(self, hidden_states, scale: float = 1.0):
assert hidden_states.shape[1] == self.channels
if self.use_conv and self.padding == 0:
pad = (0, 1, 0, 1)
hidden_states = F.pad(hidden_states, pad, mode="constant", value=0)
assert hidden_states.shape[1] == self.channels
if isinstance(self.conv, LoRACompatibleConv):
hidden_states = self.conv(hidden_states, scale)
else:
hidden_states = self.conv(hidden_states)
return hidden_states
class FirUpsample2D(nn.Module):
"""A 2D FIR upsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
fir_kernel (`tuple`, default `(1, 3, 3, 1)`):
kernel for the FIR filter.
"""
def __init__(self, channels=None, out_channels=None, use_conv=False, fir_kernel=(1, 3, 3, 1)):
super().__init__()
out_channels = out_channels if out_channels else channels
if use_conv:
self.Conv2d_0 = nn.Conv2d(channels, out_channels, kernel_size=3, stride=1, padding=1)
self.use_conv = use_conv
self.fir_kernel = fir_kernel
self.out_channels = out_channels
def _upsample_2d(self, hidden_states, weight=None, kernel=None, factor=2, gain=1):
"""Fused `upsample_2d()` followed by `Conv2d()`.
Padding is performed only once at the beginning, not between the operations. The fused op is considerably more
efficient than performing the same calculation using standard TensorFlow ops. It supports gradients of
arbitrary order.
Args:
hidden_states: Input tensor of the shape `[N, C, H, W]` or `[N, H, W, C]`.
weight: Weight tensor of the shape `[filterH, filterW, inChannels,
outChannels]`. Grouped convolution can be performed by `inChannels = x.shape[0] // numGroups`.
kernel: FIR filter of the shape `[firH, firW]` or `[firN]`
(separable). The default is `[1] * factor`, which corresponds to nearest-neighbor upsampling.
factor: Integer upsampling factor (default: 2).
gain: Scaling factor for signal magnitude (default: 1.0).
Returns:
output: Tensor of the shape `[N, C, H * factor, W * factor]` or `[N, H * factor, W * factor, C]`, and same
datatype as `hidden_states`.
"""
assert isinstance(factor, int) and factor >= 1
# Setup filter kernel.
if kernel is None:
kernel = [1] * factor
# setup kernel
kernel = torch.tensor(kernel, dtype=torch.float32)
if kernel.ndim == 1:
kernel = torch.outer(kernel, kernel)
kernel /= torch.sum(kernel)
kernel = kernel * (gain * (factor**2))
if self.use_conv:
convH = weight.shape[2]
convW = weight.shape[3]
inC = weight.shape[1]
pad_value = (kernel.shape[0] - factor) - (convW - 1)
stride = (factor, factor)
# Determine data dimensions.
output_shape = (
(hidden_states.shape[2] - 1) * factor + convH,
(hidden_states.shape[3] - 1) * factor + convW,
)
output_padding = (
output_shape[0] - (hidden_states.shape[2] - 1) * stride[0] - convH,
output_shape[1] - (hidden_states.shape[3] - 1) * stride[1] - convW,
)
assert output_padding[0] >= 0 and output_padding[1] >= 0
num_groups = hidden_states.shape[1] // inC
# Transpose weights.
weight = torch.reshape(weight, (num_groups, -1, inC, convH, convW))
weight = torch.flip(weight, dims=[3, 4]).permute(0, 2, 1, 3, 4)
weight = torch.reshape(weight, (num_groups * inC, -1, convH, convW))
inverse_conv = F.conv_transpose2d(
hidden_states, weight, stride=stride, output_padding=output_padding, padding=0
)
output = upfirdn2d_native(
inverse_conv,
torch.tensor(kernel, device=inverse_conv.device),
pad=((pad_value + 1) // 2 + factor - 1, pad_value // 2 + 1),
)
else:
pad_value = kernel.shape[0] - factor
output = upfirdn2d_native(
hidden_states,
torch.tensor(kernel, device=hidden_states.device),
up=factor,
pad=((pad_value + 1) // 2 + factor - 1, pad_value // 2),
)
return output
def forward(self, hidden_states):
if self.use_conv:
height = self._upsample_2d(hidden_states, self.Conv2d_0.weight, kernel=self.fir_kernel)
height = height + self.Conv2d_0.bias.reshape(1, -1, 1, 1)
else:
height = self._upsample_2d(hidden_states, kernel=self.fir_kernel, factor=2)
return height
class FirDownsample2D(nn.Module):
"""A 2D FIR downsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
fir_kernel (`tuple`, default `(1, 3, 3, 1)`):
kernel for the FIR filter.
"""
def __init__(self, channels=None, out_channels=None, use_conv=False, fir_kernel=(1, 3, 3, 1)):
super().__init__()
out_channels = out_channels if out_channels else channels
if use_conv:
self.Conv2d_0 = nn.Conv2d(channels, out_channels, kernel_size=3, stride=1, padding=1)
self.fir_kernel = fir_kernel
self.use_conv = use_conv
self.out_channels = out_channels
def _downsample_2d(self, hidden_states, weight=None, kernel=None, factor=2, gain=1):
"""Fused `Conv2d()` followed by `downsample_2d()`.
Padding is performed only once at the beginning, not between the operations. The fused op is considerably more
efficient than performing the same calculation using standard TensorFlow ops. It supports gradients of
arbitrary order.
Args:
hidden_states: Input tensor of the shape `[N, C, H, W]` or `[N, H, W, C]`.
weight:
Weight tensor of the shape `[filterH, filterW, inChannels, outChannels]`. Grouped convolution can be
performed by `inChannels = x.shape[0] // numGroups`.
kernel: FIR filter of the shape `[firH, firW]` or `[firN]` (separable). The default is `[1] *
factor`, which corresponds to average pooling.
factor: Integer downsampling factor (default: 2).
gain: Scaling factor for signal magnitude (default: 1.0).
Returns:
output: Tensor of the shape `[N, C, H // factor, W // factor]` or `[N, H // factor, W // factor, C]`, and
same datatype as `x`.
"""
assert isinstance(factor, int) and factor >= 1
if kernel is None:
kernel = [1] * factor
# setup kernel
kernel = torch.tensor(kernel, dtype=torch.float32)
if kernel.ndim == 1:
kernel = torch.outer(kernel, kernel)
kernel /= torch.sum(kernel)
kernel = kernel * gain
if self.use_conv:
_, _, convH, convW = weight.shape
pad_value = (kernel.shape[0] - factor) + (convW - 1)
stride_value = [factor, factor]
upfirdn_input = upfirdn2d_native(
hidden_states,
torch.tensor(kernel, device=hidden_states.device),
pad=((pad_value + 1) // 2, pad_value // 2),
)
output = F.conv2d(upfirdn_input, weight, stride=stride_value, padding=0)
else:
pad_value = kernel.shape[0] - factor
output = upfirdn2d_native(
hidden_states,
torch.tensor(kernel, device=hidden_states.device),
down=factor,
pad=((pad_value + 1) // 2, pad_value // 2),
)
return output
def forward(self, hidden_states):
if self.use_conv:
downsample_input = self._downsample_2d(hidden_states, weight=self.Conv2d_0.weight, kernel=self.fir_kernel)
hidden_states = downsample_input + self.Conv2d_0.bias.reshape(1, -1, 1, 1)
else:
hidden_states = self._downsample_2d(hidden_states, kernel=self.fir_kernel, factor=2)
return hidden_states
# downsample/upsample layer used in k-upscaler, might be able to use FirDownsample2D/DirUpsample2D instead
class KDownsample2D(nn.Module):
def __init__(self, pad_mode="reflect"):
super().__init__()
self.pad_mode = pad_mode
kernel_1d = torch.tensor([[1 / 8, 3 / 8, 3 / 8, 1 / 8]])
self.pad = kernel_1d.shape[1] // 2 - 1
self.register_buffer("kernel", kernel_1d.T @ kernel_1d, persistent=False)
def forward(self, inputs):
inputs = F.pad(inputs, (self.pad,) * 4, self.pad_mode)
weight = inputs.new_zeros([inputs.shape[1], inputs.shape[1], self.kernel.shape[0], self.kernel.shape[1]])
indices = torch.arange(inputs.shape[1], device=inputs.device)
kernel = self.kernel.to(weight)[None, :].expand(inputs.shape[1], -1, -1)
weight[indices, indices] = kernel
return F.conv2d(inputs, weight, stride=2)
class KUpsample2D(nn.Module):
def __init__(self, pad_mode="reflect"):
super().__init__()
self.pad_mode = pad_mode
kernel_1d = torch.tensor([[1 / 8, 3 / 8, 3 / 8, 1 / 8]]) * 2
self.pad = kernel_1d.shape[1] // 2 - 1
self.register_buffer("kernel", kernel_1d.T @ kernel_1d, persistent=False)
def forward(self, inputs):
inputs = F.pad(inputs, ((self.pad + 1) // 2,) * 4, self.pad_mode)
weight = inputs.new_zeros([inputs.shape[1], inputs.shape[1], self.kernel.shape[0], self.kernel.shape[1]])
indices = torch.arange(inputs.shape[1], device=inputs.device)
kernel = self.kernel.to(weight)[None, :].expand(inputs.shape[1], -1, -1)
weight[indices, indices] = kernel
return F.conv_transpose2d(inputs, weight, stride=2, padding=self.pad * 2 + 1)
class ResnetBlock2D(nn.Module):
r"""
A Resnet block.
Parameters:
in_channels (`int`): The number of channels in the input.
out_channels (`int`, *optional*, default to be `None`):
The number of output channels for the first conv2d layer. If None, same as `in_channels`.
dropout (`float`, *optional*, defaults to `0.0`): The dropout probability to use.
temb_channels (`int`, *optional*, default to `512`): the number of channels in timestep embedding.
groups (`int`, *optional*, default to `32`): The number of groups to use for the first normalization layer.
groups_out (`int`, *optional*, default to None):
The number of groups to use for the second normalization layer. if set to None, same as `groups`.
eps (`float`, *optional*, defaults to `1e-6`): The epsilon to use for the normalization.
non_linearity (`str`, *optional*, default to `"swish"`): the activation function to use.
time_embedding_norm (`str`, *optional*, default to `"default"` ): Time scale shift config.
By default, apply timestep embedding conditioning with a simple shift mechanism. Choose "scale_shift" or
"ada_group" for a stronger conditioning with scale and shift.
kernel (`torch.FloatTensor`, optional, default to None): FIR filter, see
[`~models.resnet.FirUpsample2D`] and [`~models.resnet.FirDownsample2D`].
output_scale_factor (`float`, *optional*, default to be `1.0`): the scale factor to use for the output.
use_in_shortcut (`bool`, *optional*, default to `True`):
If `True`, add a 1x1 nn.conv2d layer for skip-connection.
up (`bool`, *optional*, default to `False`): If `True`, add an upsample layer.
down (`bool`, *optional*, default to `False`): If `True`, add a downsample layer.
conv_shortcut_bias (`bool`, *optional*, default to `True`): If `True`, adds a learnable bias to the
`conv_shortcut` output.
conv_2d_out_channels (`int`, *optional*, default to `None`): the number of channels in the output.
If None, same as `out_channels`.
"""
def __init__(
self,
*,
in_channels,
out_channels=None,
conv_shortcut=False,
dropout=0.0,
temb_channels=512,
groups=32,
groups_out=None,
pre_norm=True,
eps=1e-6,
non_linearity="swish",
skip_time_act=False,
time_embedding_norm="default", # default, scale_shift, ada_group, spatial
kernel=None,
output_scale_factor=1.0,
use_in_shortcut=None,
up=False,
down=False,
conv_shortcut_bias: bool = True,
conv_2d_out_channels: Optional[int] = None,
):
super().__init__()
self.pre_norm = pre_norm
self.pre_norm = True
self.in_channels = in_channels
out_channels = in_channels if out_channels is None else out_channels
self.out_channels = out_channels
self.use_conv_shortcut = conv_shortcut
self.up = up
self.down = down
self.output_scale_factor = output_scale_factor
self.time_embedding_norm = time_embedding_norm
self.skip_time_act = skip_time_act
if groups_out is None:
groups_out = groups
if self.time_embedding_norm == "ada_group":
self.norm1 = AdaGroupNorm(temb_channels, in_channels, groups, eps=eps)
elif self.time_embedding_norm == "spatial":
self.norm1 = SpatialNorm(in_channels, temb_channels)
else:
self.norm1 = torch.nn.GroupNorm(num_groups=groups, num_channels=in_channels, eps=eps, affine=True)
self.conv1 = LoRACompatibleConv(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
if temb_channels is not None:
if self.time_embedding_norm == "default":
self.time_emb_proj = LoRACompatibleLinear(temb_channels, out_channels)
elif self.time_embedding_norm == "scale_shift":
self.time_emb_proj = LoRACompatibleLinear(temb_channels, 2 * out_channels)
elif self.time_embedding_norm == "ada_group" or self.time_embedding_norm == "spatial":
self.time_emb_proj = None
else:
raise ValueError(f"unknown time_embedding_norm : {self.time_embedding_norm} ")
else:
self.time_emb_proj = None
if self.time_embedding_norm == "ada_group":
self.norm2 = AdaGroupNorm(temb_channels, out_channels, groups_out, eps=eps)
elif self.time_embedding_norm == "spatial":
self.norm2 = SpatialNorm(out_channels, temb_channels)
else:
self.norm2 = torch.nn.GroupNorm(num_groups=groups_out, num_channels=out_channels, eps=eps, affine=True)
self.dropout = torch.nn.Dropout(dropout)
conv_2d_out_channels = conv_2d_out_channels or out_channels
self.conv2 = LoRACompatibleConv(out_channels, conv_2d_out_channels, kernel_size=3, stride=1, padding=1)
self.nonlinearity = get_activation(non_linearity)
self.upsample = self.downsample = None
if self.up:
if kernel == "fir":
fir_kernel = (1, 3, 3, 1)
self.upsample = lambda x: upsample_2d(x, kernel=fir_kernel)
elif kernel == "sde_vp":
self.upsample = partial(F.interpolate, scale_factor=2.0, mode="nearest")
else:
self.upsample = Upsample2D(in_channels, use_conv=False)
elif self.down:
if kernel == "fir":
fir_kernel = (1, 3, 3, 1)
self.downsample = lambda x: downsample_2d(x, kernel=fir_kernel)
elif kernel == "sde_vp":
self.downsample = partial(F.avg_pool2d, kernel_size=2, stride=2)
else:
self.downsample = Downsample2D(in_channels, use_conv=False, padding=1, name="op")
self.use_in_shortcut = self.in_channels != conv_2d_out_channels if use_in_shortcut is None else use_in_shortcut
self.conv_shortcut = None
if self.use_in_shortcut:
self.conv_shortcut = LoRACompatibleConv(
in_channels, conv_2d_out_channels, kernel_size=1, stride=1, padding=0, bias=conv_shortcut_bias
)
def forward(self, input_tensor, temb, scale: float = 1.0):
hidden_states = input_tensor
if self.time_embedding_norm == "ada_group" or self.time_embedding_norm == "spatial":
hidden_states = self.norm1(hidden_states, temb)
else:
hidden_states = self.norm1(hidden_states)
hidden_states = self.nonlinearity(hidden_states)
if self.upsample is not None:
# upsample_nearest_nhwc fails with large batch sizes. see https://github.com/huggingface/diffusers/issues/984
if hidden_states.shape[0] >= 64:
input_tensor = input_tensor.contiguous()
hidden_states = hidden_states.contiguous()
input_tensor = (
self.upsample(input_tensor, scale=scale)
if isinstance(self.upsample, Upsample2D)
else self.upsample(input_tensor)
)
hidden_states = (
self.upsample(hidden_states, scale=scale)
if isinstance(self.upsample, Upsample2D)
else self.upsample(hidden_states)
)
elif self.downsample is not None:
input_tensor = (
self.downsample(input_tensor, scale=scale)
if isinstance(self.downsample, Downsample2D)
else self.downsample(input_tensor)
)
hidden_states = (
self.downsample(hidden_states, scale=scale)
if isinstance(self.downsample, Downsample2D)
else self.downsample(hidden_states)
)
hidden_states = self.conv1(hidden_states, scale)
if self.time_emb_proj is not None:
if not self.skip_time_act:
temb = self.nonlinearity(temb)
temb = self.time_emb_proj(temb, scale)[:, :, None, None]
if temb is not None and self.time_embedding_norm == "default":
hidden_states = hidden_states + temb
if self.time_embedding_norm == "ada_group" or self.time_embedding_norm == "spatial":
hidden_states = self.norm2(hidden_states, temb)
else:
hidden_states = self.norm2(hidden_states)
if temb is not None and self.time_embedding_norm == "scale_shift":
scale, shift = torch.chunk(temb, 2, dim=1)
hidden_states = hidden_states * (1 + scale) + shift
hidden_states = self.nonlinearity(hidden_states)
hidden_states = self.dropout(hidden_states)
hidden_states = self.conv2(hidden_states, scale)
if self.conv_shortcut is not None:
input_tensor = self.conv_shortcut(input_tensor, scale)
output_tensor = (input_tensor + hidden_states) / self.output_scale_factor
return output_tensor
# unet_rl.py
def rearrange_dims(tensor):
if len(tensor.shape) == 2:
return tensor[:, :, None]
if len(tensor.shape) == 3:
return tensor[:, :, None, :]
elif len(tensor.shape) == 4:
return tensor[:, :, 0, :]
else:
raise ValueError(f"`len(tensor)`: {len(tensor)} has to be 2, 3 or 4.")
class Conv1dBlock(nn.Module):
"""
Conv1d --> GroupNorm --> Mish
"""
def __init__(self, inp_channels, out_channels, kernel_size, n_groups=8):
super().__init__()
self.conv1d = nn.Conv1d(inp_channels, out_channels, kernel_size, padding=kernel_size // 2)
self.group_norm = nn.GroupNorm(n_groups, out_channels)
self.mish = nn.Mish()
def forward(self, inputs):
intermediate_repr = self.conv1d(inputs)
intermediate_repr = rearrange_dims(intermediate_repr)
intermediate_repr = self.group_norm(intermediate_repr)
intermediate_repr = rearrange_dims(intermediate_repr)
output = self.mish(intermediate_repr)
return output
# unet_rl.py
class ResidualTemporalBlock1D(nn.Module):
def __init__(self, inp_channels, out_channels, embed_dim, kernel_size=5):
super().__init__()
self.conv_in = Conv1dBlock(inp_channels, out_channels, kernel_size)
self.conv_out = Conv1dBlock(out_channels, out_channels, kernel_size)
self.time_emb_act = nn.Mish()
self.time_emb = nn.Linear(embed_dim, out_channels)
self.residual_conv = (
nn.Conv1d(inp_channels, out_channels, 1) if inp_channels != out_channels else nn.Identity()
)
def forward(self, inputs, t):
"""
Args:
inputs : [ batch_size x inp_channels x horizon ]
t : [ batch_size x embed_dim ]
returns:
out : [ batch_size x out_channels x horizon ]
"""
t = self.time_emb_act(t)
t = self.time_emb(t)
out = self.conv_in(inputs) + rearrange_dims(t)
out = self.conv_out(out)
return out + self.residual_conv(inputs)
def upsample_2d(hidden_states, kernel=None, factor=2, gain=1):
r"""Upsample2D a batch of 2D images with the given filter.
Accepts a batch of 2D images of the shape `[N, C, H, W]` or `[N, H, W, C]` and upsamples each image with the given
filter. The filter is normalized so that if the input pixels are constant, they will be scaled by the specified
`gain`. Pixels outside the image are assumed to be zero, and the filter is padded with zeros so that its shape is
a: multiple of the upsampling factor.
Args:
hidden_states: Input tensor of the shape `[N, C, H, W]` or `[N, H, W, C]`.
kernel: FIR filter of the shape `[firH, firW]` or `[firN]`
(separable). The default is `[1] * factor`, which corresponds to nearest-neighbor upsampling.
factor: Integer upsampling factor (default: 2).
gain: Scaling factor for signal magnitude (default: 1.0).
Returns:
output: Tensor of the shape `[N, C, H * factor, W * factor]`
"""
assert isinstance(factor, int) and factor >= 1
if kernel is None:
kernel = [1] * factor
kernel = torch.tensor(kernel, dtype=torch.float32)
if kernel.ndim == 1:
kernel = torch.outer(kernel, kernel)
kernel /= torch.sum(kernel)
kernel = kernel * (gain * (factor**2))
pad_value = kernel.shape[0] - factor
output = upfirdn2d_native(
hidden_states,
kernel.to(device=hidden_states.device),
up=factor,
pad=((pad_value + 1) // 2 + factor - 1, pad_value // 2),
)
return output
def downsample_2d(hidden_states, kernel=None, factor=2, gain=1):
r"""Downsample2D a batch of 2D images with the given filter.
Accepts a batch of 2D images of the shape `[N, C, H, W]` or `[N, H, W, C]` and downsamples each image with the
given filter. The filter is normalized so that if the input pixels are constant, they will be scaled by the
specified `gain`. Pixels outside the image are assumed to be zero, and the filter is padded with zeros so that its
shape is a multiple of the downsampling factor.
Args:
hidden_states: Input tensor of the shape `[N, C, H, W]` or `[N, H, W, C]`.
kernel: FIR filter of the shape `[firH, firW]` or `[firN]`
(separable). The default is `[1] * factor`, which corresponds to average pooling.
factor: Integer downsampling factor (default: 2).
gain: Scaling factor for signal magnitude (default: 1.0).
Returns:
output: Tensor of the shape `[N, C, H // factor, W // factor]`
"""
assert isinstance(factor, int) and factor >= 1
if kernel is None:
kernel = [1] * factor
kernel = torch.tensor(kernel, dtype=torch.float32)
if kernel.ndim == 1:
kernel = torch.outer(kernel, kernel)
kernel /= torch.sum(kernel)
kernel = kernel * gain
pad_value = kernel.shape[0] - factor
output = upfirdn2d_native(
hidden_states, kernel.to(device=hidden_states.device), down=factor, pad=((pad_value + 1) // 2, pad_value // 2)
)
return output
def upfirdn2d_native(tensor, kernel, up=1, down=1, pad=(0, 0)):
up_x = up_y = up
down_x = down_y = down
pad_x0 = pad_y0 = pad[0]
pad_x1 = pad_y1 = pad[1]
_, channel, in_h, in_w = tensor.shape
tensor = tensor.reshape(-1, in_h, in_w, 1)
_, in_h, in_w, minor = tensor.shape
kernel_h, kernel_w = kernel.shape
out = tensor.view(-1, in_h, 1, in_w, 1, minor)
out = F.pad(out, [0, 0, 0, up_x - 1, 0, 0, 0, up_y - 1])
out = out.view(-1, in_h * up_y, in_w * up_x, minor)
out = F.pad(out, [0, 0, max(pad_x0, 0), max(pad_x1, 0), max(pad_y0, 0), max(pad_y1, 0)])
out = out.to(tensor.device) # Move back to mps if necessary
out = out[
:,
max(-pad_y0, 0) : out.shape[1] - max(-pad_y1, 0),
max(-pad_x0, 0) : out.shape[2] - max(-pad_x1, 0),
:,
]
out = out.permute(0, 3, 1, 2)
out = out.reshape([-1, 1, in_h * up_y + pad_y0 + pad_y1, in_w * up_x + pad_x0 + pad_x1])
w = torch.flip(kernel, [0, 1]).view(1, 1, kernel_h, kernel_w)
out = F.conv2d(out, w)
out = out.reshape(
-1,
minor,
in_h * up_y + pad_y0 + pad_y1 - kernel_h + 1,
in_w * up_x + pad_x0 + pad_x1 - kernel_w + 1,
)
out = out.permute(0, 2, 3, 1)
out = out[:, ::down_y, ::down_x, :]
out_h = (in_h * up_y + pad_y0 + pad_y1 - kernel_h) // down_y + 1
out_w = (in_w * up_x + pad_x0 + pad_x1 - kernel_w) // down_x + 1
return out.view(-1, channel, out_h, out_w)
class TemporalConvLayer(nn.Module):
"""
Temporal convolutional layer that can be used for video (sequence of images) input Code mostly copied from:
https://github.com/modelscope/modelscope/blob/1509fdb973e5871f37148a4b5e5964cafd43e64d/modelscope/models/multi_modal/video_synthesis/unet_sd.py#L1016
"""
def __init__(self, in_dim, out_dim=None, dropout=0.0):
super().__init__()
out_dim = out_dim or in_dim
self.in_dim = in_dim
self.out_dim = out_dim
# conv layers
self.conv1 = nn.Sequential(
nn.GroupNorm(32, in_dim), nn.SiLU(), nn.Conv3d(in_dim, out_dim, (3, 1, 1), padding=(1, 0, 0))
)
self.conv2 = nn.Sequential(
nn.GroupNorm(32, out_dim),
nn.SiLU(),
nn.Dropout(dropout),
nn.Conv3d(out_dim, in_dim, (3, 1, 1), padding=(1, 0, 0)),
)
self.conv3 = nn.Sequential(
nn.GroupNorm(32, out_dim),
nn.SiLU(),
nn.Dropout(dropout),
nn.Conv3d(out_dim, in_dim, (3, 1, 1), padding=(1, 0, 0)),
)
self.conv4 = nn.Sequential(
nn.GroupNorm(32, out_dim),
nn.SiLU(),
nn.Dropout(dropout),
nn.Conv3d(out_dim, in_dim, (3, 1, 1), padding=(1, 0, 0)),
)
# zero out the last layer params,so the conv block is identity
nn.init.zeros_(self.conv4[-1].weight)
nn.init.zeros_(self.conv4[-1].bias)
def forward(self, hidden_states, num_frames=1):
hidden_states = (
hidden_states[None, :].reshape((-1, num_frames) + hidden_states.shape[1:]).permute(0, 2, 1, 3, 4)
)
identity = hidden_states
hidden_states = self.conv1(hidden_states)
hidden_states = self.conv2(hidden_states)
hidden_states = self.conv3(hidden_states)
hidden_states = self.conv4(hidden_states)
hidden_states = identity + hidden_states
hidden_states = hidden_states.permute(0, 2, 1, 3, 4).reshape(
(hidden_states.shape[0] * hidden_states.shape[2], -1) + hidden_states.shape[3:]
)
return hidden_states
| diffusers-main | src/diffusers/models/resnet.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Optional, Tuple, Union
import torch
import torch.nn as nn
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils.accelerate_utils import apply_forward_hook
from .autoencoder_kl import AutoencoderKLOutput
from .modeling_utils import ModelMixin
from .vae import DecoderOutput, DiagonalGaussianDistribution, Encoder, MaskConditionDecoder
class AsymmetricAutoencoderKL(ModelMixin, ConfigMixin):
r"""
Designing a Better Asymmetric VQGAN for StableDiffusion https://arxiv.org/abs/2306.04632 . A VAE model with KL loss
for encoding images into latents and decoding latent representations into images.
This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
for all models (such as downloading or saving).
Parameters:
in_channels (int, *optional*, defaults to 3): Number of channels in the input image.
out_channels (int, *optional*, defaults to 3): Number of channels in the output.
down_block_types (`Tuple[str]`, *optional*, defaults to `("DownEncoderBlock2D",)`):
Tuple of downsample block types.
down_block_out_channels (`Tuple[int]`, *optional*, defaults to `(64,)`):
Tuple of down block output channels.
layers_per_down_block (`int`, *optional*, defaults to `1`):
Number layers for down block.
up_block_types (`Tuple[str]`, *optional*, defaults to `("UpDecoderBlock2D",)`):
Tuple of upsample block types.
up_block_out_channels (`Tuple[int]`, *optional*, defaults to `(64,)`):
Tuple of up block output channels.
layers_per_up_block (`int`, *optional*, defaults to `1`):
Number layers for up block.
act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
latent_channels (`int`, *optional*, defaults to 4): Number of channels in the latent space.
sample_size (`int`, *optional*, defaults to `32`): Sample input size.
norm_num_groups (`int`, *optional*, defaults to `32`):
Number of groups to use for the first normalization layer in ResNet blocks.
scaling_factor (`float`, *optional*, defaults to 0.18215):
The component-wise standard deviation of the trained latent space computed using the first batch of the
training set. This is used to scale the latent space to have unit variance when training the diffusion
model. The latents are scaled with the formula `z = z * scaling_factor` before being passed to the
diffusion model. When decoding, the latents are scaled back to the original scale with the formula: `z = 1
/ scaling_factor * z`. For more details, refer to sections 4.3.2 and D.1 of the [High-Resolution Image
Synthesis with Latent Diffusion Models](https://arxiv.org/abs/2112.10752) paper.
"""
@register_to_config
def __init__(
self,
in_channels: int = 3,
out_channels: int = 3,
down_block_types: Tuple[str] = ("DownEncoderBlock2D",),
down_block_out_channels: Tuple[int] = (64,),
layers_per_down_block: int = 1,
up_block_types: Tuple[str] = ("UpDecoderBlock2D",),
up_block_out_channels: Tuple[int] = (64,),
layers_per_up_block: int = 1,
act_fn: str = "silu",
latent_channels: int = 4,
norm_num_groups: int = 32,
sample_size: int = 32,
scaling_factor: float = 0.18215,
) -> None:
super().__init__()
# pass init params to Encoder
self.encoder = Encoder(
in_channels=in_channels,
out_channels=latent_channels,
down_block_types=down_block_types,
block_out_channels=down_block_out_channels,
layers_per_block=layers_per_down_block,
act_fn=act_fn,
norm_num_groups=norm_num_groups,
double_z=True,
)
# pass init params to Decoder
self.decoder = MaskConditionDecoder(
in_channels=latent_channels,
out_channels=out_channels,
up_block_types=up_block_types,
block_out_channels=up_block_out_channels,
layers_per_block=layers_per_up_block,
act_fn=act_fn,
norm_num_groups=norm_num_groups,
)
self.quant_conv = nn.Conv2d(2 * latent_channels, 2 * latent_channels, 1)
self.post_quant_conv = nn.Conv2d(latent_channels, latent_channels, 1)
self.use_slicing = False
self.use_tiling = False
@apply_forward_hook
def encode(self, x: torch.FloatTensor, return_dict: bool = True) -> AutoencoderKLOutput:
h = self.encoder(x)
moments = self.quant_conv(h)
posterior = DiagonalGaussianDistribution(moments)
if not return_dict:
return (posterior,)
return AutoencoderKLOutput(latent_dist=posterior)
def _decode(
self,
z: torch.FloatTensor,
image: Optional[torch.FloatTensor] = None,
mask: Optional[torch.FloatTensor] = None,
return_dict: bool = True,
) -> Union[DecoderOutput, torch.FloatTensor]:
z = self.post_quant_conv(z)
dec = self.decoder(z, image, mask)
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
@apply_forward_hook
def decode(
self,
z: torch.FloatTensor,
image: Optional[torch.FloatTensor] = None,
mask: Optional[torch.FloatTensor] = None,
return_dict: bool = True,
) -> Union[DecoderOutput, torch.FloatTensor]:
decoded = self._decode(z, image, mask).sample
if not return_dict:
return (decoded,)
return DecoderOutput(sample=decoded)
def forward(
self,
sample: torch.FloatTensor,
mask: Optional[torch.FloatTensor] = None,
sample_posterior: bool = False,
return_dict: bool = True,
generator: Optional[torch.Generator] = None,
) -> Union[DecoderOutput, torch.FloatTensor]:
r"""
Args:
sample (`torch.FloatTensor`): Input sample.
mask (`torch.FloatTensor`, *optional*, defaults to `None`): Optional inpainting mask.
sample_posterior (`bool`, *optional*, defaults to `False`):
Whether to sample from the posterior.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`DecoderOutput`] instead of a plain tuple.
"""
x = sample
posterior = self.encode(x).latent_dist
if sample_posterior:
z = posterior.sample(generator=generator)
else:
z = posterior.mode()
dec = self.decode(z, sample, mask).sample
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
| diffusers-main | src/diffusers/models/autoencoder_asym_kl.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import torch
import torch.nn as nn
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from .embeddings import GaussianFourierProjection, TimestepEmbedding, Timesteps
from .modeling_utils import ModelMixin
from .unet_1d_blocks import get_down_block, get_mid_block, get_out_block, get_up_block
@dataclass
class UNet1DOutput(BaseOutput):
"""
The output of [`UNet1DModel`].
Args:
sample (`torch.FloatTensor` of shape `(batch_size, num_channels, sample_size)`):
The hidden states output from the last layer of the model.
"""
sample: torch.FloatTensor
class UNet1DModel(ModelMixin, ConfigMixin):
r"""
A 1D UNet model that takes a noisy sample and a timestep and returns a sample shaped output.
This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
for all models (such as downloading or saving).
Parameters:
sample_size (`int`, *optional*): Default length of sample. Should be adaptable at runtime.
in_channels (`int`, *optional*, defaults to 2): Number of channels in the input sample.
out_channels (`int`, *optional*, defaults to 2): Number of channels in the output.
extra_in_channels (`int`, *optional*, defaults to 0):
Number of additional channels to be added to the input of the first down block. Useful for cases where the
input data has more channels than what the model was initially designed for.
time_embedding_type (`str`, *optional*, defaults to `"fourier"`): Type of time embedding to use.
freq_shift (`float`, *optional*, defaults to 0.0): Frequency shift for Fourier time embedding.
flip_sin_to_cos (`bool`, *optional*, defaults to `False`):
Whether to flip sin to cos for Fourier time embedding.
down_block_types (`Tuple[str]`, *optional*, defaults to `("DownBlock1DNoSkip", "DownBlock1D", "AttnDownBlock1D")`):
Tuple of downsample block types.
up_block_types (`Tuple[str]`, *optional*, defaults to `("AttnUpBlock1D", "UpBlock1D", "UpBlock1DNoSkip")`):
Tuple of upsample block types.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(32, 32, 64)`):
Tuple of block output channels.
mid_block_type (`str`, *optional*, defaults to `"UNetMidBlock1D"`): Block type for middle of UNet.
out_block_type (`str`, *optional*, defaults to `None`): Optional output processing block of UNet.
act_fn (`str`, *optional*, defaults to `None`): Optional activation function in UNet blocks.
norm_num_groups (`int`, *optional*, defaults to 8): The number of groups for normalization.
layers_per_block (`int`, *optional*, defaults to 1): The number of layers per block.
downsample_each_block (`int`, *optional*, defaults to `False`):
Experimental feature for using a UNet without upsampling.
"""
@register_to_config
def __init__(
self,
sample_size: int = 65536,
sample_rate: Optional[int] = None,
in_channels: int = 2,
out_channels: int = 2,
extra_in_channels: int = 0,
time_embedding_type: str = "fourier",
flip_sin_to_cos: bool = True,
use_timestep_embedding: bool = False,
freq_shift: float = 0.0,
down_block_types: Tuple[str] = ("DownBlock1DNoSkip", "DownBlock1D", "AttnDownBlock1D"),
up_block_types: Tuple[str] = ("AttnUpBlock1D", "UpBlock1D", "UpBlock1DNoSkip"),
mid_block_type: Tuple[str] = "UNetMidBlock1D",
out_block_type: str = None,
block_out_channels: Tuple[int] = (32, 32, 64),
act_fn: str = None,
norm_num_groups: int = 8,
layers_per_block: int = 1,
downsample_each_block: bool = False,
):
super().__init__()
self.sample_size = sample_size
# time
if time_embedding_type == "fourier":
self.time_proj = GaussianFourierProjection(
embedding_size=8, set_W_to_weight=False, log=False, flip_sin_to_cos=flip_sin_to_cos
)
timestep_input_dim = 2 * block_out_channels[0]
elif time_embedding_type == "positional":
self.time_proj = Timesteps(
block_out_channels[0], flip_sin_to_cos=flip_sin_to_cos, downscale_freq_shift=freq_shift
)
timestep_input_dim = block_out_channels[0]
if use_timestep_embedding:
time_embed_dim = block_out_channels[0] * 4
self.time_mlp = TimestepEmbedding(
in_channels=timestep_input_dim,
time_embed_dim=time_embed_dim,
act_fn=act_fn,
out_dim=block_out_channels[0],
)
self.down_blocks = nn.ModuleList([])
self.mid_block = None
self.up_blocks = nn.ModuleList([])
self.out_block = None
# down
output_channel = in_channels
for i, down_block_type in enumerate(down_block_types):
input_channel = output_channel
output_channel = block_out_channels[i]
if i == 0:
input_channel += extra_in_channels
is_final_block = i == len(block_out_channels) - 1
down_block = get_down_block(
down_block_type,
num_layers=layers_per_block,
in_channels=input_channel,
out_channels=output_channel,
temb_channels=block_out_channels[0],
add_downsample=not is_final_block or downsample_each_block,
)
self.down_blocks.append(down_block)
# mid
self.mid_block = get_mid_block(
mid_block_type,
in_channels=block_out_channels[-1],
mid_channels=block_out_channels[-1],
out_channels=block_out_channels[-1],
embed_dim=block_out_channels[0],
num_layers=layers_per_block,
add_downsample=downsample_each_block,
)
# up
reversed_block_out_channels = list(reversed(block_out_channels))
output_channel = reversed_block_out_channels[0]
if out_block_type is None:
final_upsample_channels = out_channels
else:
final_upsample_channels = block_out_channels[0]
for i, up_block_type in enumerate(up_block_types):
prev_output_channel = output_channel
output_channel = (
reversed_block_out_channels[i + 1] if i < len(up_block_types) - 1 else final_upsample_channels
)
is_final_block = i == len(block_out_channels) - 1
up_block = get_up_block(
up_block_type,
num_layers=layers_per_block,
in_channels=prev_output_channel,
out_channels=output_channel,
temb_channels=block_out_channels[0],
add_upsample=not is_final_block,
)
self.up_blocks.append(up_block)
prev_output_channel = output_channel
# out
num_groups_out = norm_num_groups if norm_num_groups is not None else min(block_out_channels[0] // 4, 32)
self.out_block = get_out_block(
out_block_type=out_block_type,
num_groups_out=num_groups_out,
embed_dim=block_out_channels[0],
out_channels=out_channels,
act_fn=act_fn,
fc_dim=block_out_channels[-1] // 4,
)
def forward(
self,
sample: torch.FloatTensor,
timestep: Union[torch.Tensor, float, int],
return_dict: bool = True,
) -> Union[UNet1DOutput, Tuple]:
r"""
The [`UNet1DModel`] forward method.
Args:
sample (`torch.FloatTensor`):
The noisy input tensor with the following shape `(batch_size, num_channels, sample_size)`.
timestep (`torch.FloatTensor` or `float` or `int`): The number of timesteps to denoise an input.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.unet_1d.UNet1DOutput`] instead of a plain tuple.
Returns:
[`~models.unet_1d.UNet1DOutput`] or `tuple`:
If `return_dict` is True, an [`~models.unet_1d.UNet1DOutput`] is returned, otherwise a `tuple` is
returned where the first element is the sample tensor.
"""
# 1. time
timesteps = timestep
if not torch.is_tensor(timesteps):
timesteps = torch.tensor([timesteps], dtype=torch.long, device=sample.device)
elif torch.is_tensor(timesteps) and len(timesteps.shape) == 0:
timesteps = timesteps[None].to(sample.device)
timestep_embed = self.time_proj(timesteps)
if self.config.use_timestep_embedding:
timestep_embed = self.time_mlp(timestep_embed)
else:
timestep_embed = timestep_embed[..., None]
timestep_embed = timestep_embed.repeat([1, 1, sample.shape[2]]).to(sample.dtype)
timestep_embed = timestep_embed.broadcast_to((sample.shape[:1] + timestep_embed.shape[1:]))
# 2. down
down_block_res_samples = ()
for downsample_block in self.down_blocks:
sample, res_samples = downsample_block(hidden_states=sample, temb=timestep_embed)
down_block_res_samples += res_samples
# 3. mid
if self.mid_block:
sample = self.mid_block(sample, timestep_embed)
# 4. up
for i, upsample_block in enumerate(self.up_blocks):
res_samples = down_block_res_samples[-1:]
down_block_res_samples = down_block_res_samples[:-1]
sample = upsample_block(sample, res_hidden_states_tuple=res_samples, temb=timestep_embed)
# 5. post-process
if self.out_block:
sample = self.out_block(sample, timestep_embed)
if not return_dict:
return (sample,)
return UNet1DOutput(sample=sample)
| diffusers-main | src/diffusers/models/unet_1d.py |
# coding=utf-8
# Copyright 2023 The HuggingFace Inc. team.
# Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import inspect
import itertools
import os
import re
from functools import partial
from typing import Any, Callable, List, Optional, Tuple, Union
import safetensors
import torch
from huggingface_hub import create_repo
from torch import Tensor, device, nn
from .. import __version__
from ..utils import (
CONFIG_NAME,
DIFFUSERS_CACHE,
FLAX_WEIGHTS_NAME,
HF_HUB_OFFLINE,
SAFETENSORS_WEIGHTS_NAME,
WEIGHTS_NAME,
_add_variant,
_get_model_file,
deprecate,
is_accelerate_available,
is_torch_version,
logging,
)
from ..utils.hub_utils import PushToHubMixin
logger = logging.get_logger(__name__)
if is_torch_version(">=", "1.9.0"):
_LOW_CPU_MEM_USAGE_DEFAULT = True
else:
_LOW_CPU_MEM_USAGE_DEFAULT = False
if is_accelerate_available():
import accelerate
from accelerate.utils import set_module_tensor_to_device
from accelerate.utils.versions import is_torch_version
def get_parameter_device(parameter: torch.nn.Module):
try:
parameters_and_buffers = itertools.chain(parameter.parameters(), parameter.buffers())
return next(parameters_and_buffers).device
except StopIteration:
# For torch.nn.DataParallel compatibility in PyTorch 1.5
def find_tensor_attributes(module: torch.nn.Module) -> List[Tuple[str, Tensor]]:
tuples = [(k, v) for k, v in module.__dict__.items() if torch.is_tensor(v)]
return tuples
gen = parameter._named_members(get_members_fn=find_tensor_attributes)
first_tuple = next(gen)
return first_tuple[1].device
def get_parameter_dtype(parameter: torch.nn.Module):
try:
params = tuple(parameter.parameters())
if len(params) > 0:
return params[0].dtype
buffers = tuple(parameter.buffers())
if len(buffers) > 0:
return buffers[0].dtype
except StopIteration:
# For torch.nn.DataParallel compatibility in PyTorch 1.5
def find_tensor_attributes(module: torch.nn.Module) -> List[Tuple[str, Tensor]]:
tuples = [(k, v) for k, v in module.__dict__.items() if torch.is_tensor(v)]
return tuples
gen = parameter._named_members(get_members_fn=find_tensor_attributes)
first_tuple = next(gen)
return first_tuple[1].dtype
def load_state_dict(checkpoint_file: Union[str, os.PathLike], variant: Optional[str] = None):
"""
Reads a checkpoint file, returning properly formatted errors if they arise.
"""
try:
if os.path.basename(checkpoint_file) == _add_variant(WEIGHTS_NAME, variant):
return torch.load(checkpoint_file, map_location="cpu")
else:
return safetensors.torch.load_file(checkpoint_file, device="cpu")
except Exception as e:
try:
with open(checkpoint_file) as f:
if f.read().startswith("version"):
raise OSError(
"You seem to have cloned a repository without having git-lfs installed. Please install "
"git-lfs and run `git lfs install` followed by `git lfs pull` in the folder "
"you cloned."
)
else:
raise ValueError(
f"Unable to locate the file {checkpoint_file} which is necessary to load this pretrained "
"model. Make sure you have saved the model properly."
) from e
except (UnicodeDecodeError, ValueError):
raise OSError(
f"Unable to load weights from checkpoint file for '{checkpoint_file}' "
f"at '{checkpoint_file}'. "
"If you tried to load a PyTorch model from a TF 2.0 checkpoint, please set from_tf=True."
)
def load_model_dict_into_meta(model, state_dict, device=None, dtype=None, model_name_or_path=None):
device = device or torch.device("cpu")
dtype = dtype or torch.float32
unexpected_keys = []
empty_state_dict = model.state_dict()
for param_name, param in state_dict.items():
if param_name not in empty_state_dict:
unexpected_keys.append(param_name)
continue
if empty_state_dict[param_name].shape != param.shape:
model_name_or_path_str = f"{model_name_or_path} " if model_name_or_path is not None else ""
raise ValueError(
f"Cannot load {model_name_or_path_str}because {param_name} expected shape {empty_state_dict[param_name]}, but got {param.shape}. If you want to instead overwrite randomly initialized weights, please make sure to pass both `low_cpu_mem_usage=False` and `ignore_mismatched_sizes=True`. For more information, see also: https://github.com/huggingface/diffusers/issues/1619#issuecomment-1345604389 as an example."
)
accepts_dtype = "dtype" in set(inspect.signature(set_module_tensor_to_device).parameters.keys())
if accepts_dtype:
set_module_tensor_to_device(model, param_name, device, value=param, dtype=dtype)
else:
set_module_tensor_to_device(model, param_name, device, value=param)
return unexpected_keys
def _load_state_dict_into_model(model_to_load, state_dict):
# Convert old format to new format if needed from a PyTorch state_dict
# copy state_dict so _load_from_state_dict can modify it
state_dict = state_dict.copy()
error_msgs = []
# PyTorch's `_load_from_state_dict` does not copy parameters in a module's descendants
# so we need to apply the function recursively.
def load(module: torch.nn.Module, prefix=""):
args = (state_dict, prefix, {}, True, [], [], error_msgs)
module._load_from_state_dict(*args)
for name, child in module._modules.items():
if child is not None:
load(child, prefix + name + ".")
load(model_to_load)
return error_msgs
class ModelMixin(torch.nn.Module, PushToHubMixin):
r"""
Base class for all models.
[`ModelMixin`] takes care of storing the model configuration and provides methods for loading, downloading and
saving models.
- **config_name** ([`str`]) -- Filename to save a model to when calling [`~models.ModelMixin.save_pretrained`].
"""
config_name = CONFIG_NAME
_automatically_saved_args = ["_diffusers_version", "_class_name", "_name_or_path"]
_supports_gradient_checkpointing = False
_keys_to_ignore_on_load_unexpected = None
def __init__(self):
super().__init__()
def __getattr__(self, name: str) -> Any:
"""The only reason we overwrite `getattr` here is to gracefully deprecate accessing
config attributes directly. See https://github.com/huggingface/diffusers/pull/3129 We need to overwrite
__getattr__ here in addition so that we don't trigger `torch.nn.Module`'s __getattr__':
https://pytorch.org/docs/stable/_modules/torch/nn/modules/module.html#Module
"""
is_in_config = "_internal_dict" in self.__dict__ and hasattr(self.__dict__["_internal_dict"], name)
is_attribute = name in self.__dict__
if is_in_config and not is_attribute:
deprecation_message = f"Accessing config attribute `{name}` directly via '{type(self).__name__}' object attribute is deprecated. Please access '{name}' over '{type(self).__name__}'s config object instead, e.g. 'unet.config.{name}'."
deprecate("direct config name access", "1.0.0", deprecation_message, standard_warn=False, stacklevel=3)
return self._internal_dict[name]
# call PyTorch's https://pytorch.org/docs/stable/_modules/torch/nn/modules/module.html#Module
return super().__getattr__(name)
@property
def is_gradient_checkpointing(self) -> bool:
"""
Whether gradient checkpointing is activated for this model or not.
"""
return any(hasattr(m, "gradient_checkpointing") and m.gradient_checkpointing for m in self.modules())
def enable_gradient_checkpointing(self):
"""
Activates gradient checkpointing for the current model (may be referred to as *activation checkpointing* or
*checkpoint activations* in other frameworks).
"""
if not self._supports_gradient_checkpointing:
raise ValueError(f"{self.__class__.__name__} does not support gradient checkpointing.")
self.apply(partial(self._set_gradient_checkpointing, value=True))
def disable_gradient_checkpointing(self):
"""
Deactivates gradient checkpointing for the current model (may be referred to as *activation checkpointing* or
*checkpoint activations* in other frameworks).
"""
if self._supports_gradient_checkpointing:
self.apply(partial(self._set_gradient_checkpointing, value=False))
def set_use_memory_efficient_attention_xformers(
self, valid: bool, attention_op: Optional[Callable] = None
) -> None:
# Recursively walk through all the children.
# Any children which exposes the set_use_memory_efficient_attention_xformers method
# gets the message
def fn_recursive_set_mem_eff(module: torch.nn.Module):
if hasattr(module, "set_use_memory_efficient_attention_xformers"):
module.set_use_memory_efficient_attention_xformers(valid, attention_op)
for child in module.children():
fn_recursive_set_mem_eff(child)
for module in self.children():
if isinstance(module, torch.nn.Module):
fn_recursive_set_mem_eff(module)
def enable_xformers_memory_efficient_attention(self, attention_op: Optional[Callable] = None):
r"""
Enable memory efficient attention from [xFormers](https://facebookresearch.github.io/xformers/).
When this option is enabled, you should observe lower GPU memory usage and a potential speed up during
inference. Speed up during training is not guaranteed.
<Tip warning={true}>
⚠️ When memory efficient attention and sliced attention are both enabled, memory efficient attention takes
precedent.
</Tip>
Parameters:
attention_op (`Callable`, *optional*):
Override the default `None` operator for use as `op` argument to the
[`memory_efficient_attention()`](https://facebookresearch.github.io/xformers/components/ops.html#xformers.ops.memory_efficient_attention)
function of xFormers.
Examples:
```py
>>> import torch
>>> from diffusers import UNet2DConditionModel
>>> from xformers.ops import MemoryEfficientAttentionFlashAttentionOp
>>> model = UNet2DConditionModel.from_pretrained(
... "stabilityai/stable-diffusion-2-1", subfolder="unet", torch_dtype=torch.float16
... )
>>> model = model.to("cuda")
>>> model.enable_xformers_memory_efficient_attention(attention_op=MemoryEfficientAttentionFlashAttentionOp)
```
"""
self.set_use_memory_efficient_attention_xformers(True, attention_op)
def disable_xformers_memory_efficient_attention(self):
r"""
Disable memory efficient attention from [xFormers](https://facebookresearch.github.io/xformers/).
"""
self.set_use_memory_efficient_attention_xformers(False)
def save_pretrained(
self,
save_directory: Union[str, os.PathLike],
is_main_process: bool = True,
save_function: Callable = None,
safe_serialization: bool = True,
variant: Optional[str] = None,
push_to_hub: bool = False,
**kwargs,
):
"""
Save a model and its configuration file to a directory so that it can be reloaded using the
[`~models.ModelMixin.from_pretrained`] class method.
Arguments:
save_directory (`str` or `os.PathLike`):
Directory to save a model and its configuration file to. Will be created if it doesn't exist.
is_main_process (`bool`, *optional*, defaults to `True`):
Whether the process calling this is the main process or not. Useful during distributed training and you
need to call this function on all processes. In this case, set `is_main_process=True` only on the main
process to avoid race conditions.
save_function (`Callable`):
The function to use to save the state dictionary. Useful during distributed training when you need to
replace `torch.save` with another method. Can be configured with the environment variable
`DIFFUSERS_SAVE_MODE`.
safe_serialization (`bool`, *optional*, defaults to `True`):
Whether to save the model using `safetensors` or the traditional PyTorch way with `pickle`.
variant (`str`, *optional*):
If specified, weights are saved in the format `pytorch_model.<variant>.bin`.
push_to_hub (`bool`, *optional*, defaults to `False`):
Whether or not to push your model to the Hugging Face Hub after saving it. You can specify the
repository you want to push to with `repo_id` (will default to the name of `save_directory` in your
namespace).
kwargs (`Dict[str, Any]`, *optional*):
Additional keyword arguments passed along to the [`~utils.PushToHubMixin.push_to_hub`] method.
"""
if os.path.isfile(save_directory):
logger.error(f"Provided path ({save_directory}) should be a directory, not a file")
return
os.makedirs(save_directory, exist_ok=True)
if push_to_hub:
commit_message = kwargs.pop("commit_message", None)
private = kwargs.pop("private", False)
create_pr = kwargs.pop("create_pr", False)
token = kwargs.pop("token", None)
repo_id = kwargs.pop("repo_id", save_directory.split(os.path.sep)[-1])
repo_id = create_repo(repo_id, exist_ok=True, private=private, token=token).repo_id
# Only save the model itself if we are using distributed training
model_to_save = self
# Attach architecture to the config
# Save the config
if is_main_process:
model_to_save.save_config(save_directory)
# Save the model
state_dict = model_to_save.state_dict()
weights_name = SAFETENSORS_WEIGHTS_NAME if safe_serialization else WEIGHTS_NAME
weights_name = _add_variant(weights_name, variant)
# Save the model
if safe_serialization:
safetensors.torch.save_file(
state_dict, os.path.join(save_directory, weights_name), metadata={"format": "pt"}
)
else:
torch.save(state_dict, os.path.join(save_directory, weights_name))
logger.info(f"Model weights saved in {os.path.join(save_directory, weights_name)}")
if push_to_hub:
self._upload_folder(
save_directory,
repo_id,
token=token,
commit_message=commit_message,
create_pr=create_pr,
)
@classmethod
def from_pretrained(cls, pretrained_model_name_or_path: Optional[Union[str, os.PathLike]], **kwargs):
r"""
Instantiate a pretrained PyTorch model from a pretrained model configuration.
The model is set in evaluation mode - `model.eval()` - by default, and dropout modules are deactivated. To
train the model, set it back in training mode with `model.train()`.
Parameters:
pretrained_model_name_or_path (`str` or `os.PathLike`, *optional*):
Can be either:
- A string, the *model id* (for example `google/ddpm-celebahq-256`) of a pretrained model hosted on
the Hub.
- A path to a *directory* (for example `./my_model_directory`) containing the model weights saved
with [`~ModelMixin.save_pretrained`].
cache_dir (`Union[str, os.PathLike]`, *optional*):
Path to a directory where a downloaded pretrained model configuration is cached if the standard cache
is not used.
torch_dtype (`str` or `torch.dtype`, *optional*):
Override the default `torch.dtype` and load the model with another dtype. If `"auto"` is passed, the
dtype is automatically derived from the model's weights.
force_download (`bool`, *optional*, defaults to `False`):
Whether or not to force the (re-)download of the model weights and configuration files, overriding the
cached versions if they exist.
resume_download (`bool`, *optional*, defaults to `False`):
Whether or not to resume downloading the model weights and configuration files. If set to `False`, any
incompletely downloaded files are deleted.
proxies (`Dict[str, str]`, *optional*):
A dictionary of proxy servers to use by protocol or endpoint, for example, `{'http': 'foo.bar:3128',
'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
output_loading_info (`bool`, *optional*, defaults to `False`):
Whether or not to also return a dictionary containing missing keys, unexpected keys and error messages.
local_files_only(`bool`, *optional*, defaults to `False`):
Whether to only load local model weights and configuration files or not. If set to `True`, the model
won't be downloaded from the Hub.
use_auth_token (`str` or *bool*, *optional*):
The token to use as HTTP bearer authorization for remote files. If `True`, the token generated from
`diffusers-cli login` (stored in `~/.huggingface`) is used.
revision (`str`, *optional*, defaults to `"main"`):
The specific model version to use. It can be a branch name, a tag name, a commit id, or any identifier
allowed by Git.
from_flax (`bool`, *optional*, defaults to `False`):
Load the model weights from a Flax checkpoint save file.
subfolder (`str`, *optional*, defaults to `""`):
The subfolder location of a model file within a larger model repository on the Hub or locally.
mirror (`str`, *optional*):
Mirror source to resolve accessibility issues if you're downloading a model in China. We do not
guarantee the timeliness or safety of the source, and you should refer to the mirror site for more
information.
device_map (`str` or `Dict[str, Union[int, str, torch.device]]`, *optional*):
A map that specifies where each submodule should go. It doesn't need to be defined for each
parameter/buffer name; once a given module name is inside, every submodule of it will be sent to the
same device.
Set `device_map="auto"` to have 🤗 Accelerate automatically compute the most optimized `device_map`. For
more information about each option see [designing a device
map](https://hf.co/docs/accelerate/main/en/usage_guides/big_modeling#designing-a-device-map).
max_memory (`Dict`, *optional*):
A dictionary device identifier for the maximum memory. Will default to the maximum memory available for
each GPU and the available CPU RAM if unset.
offload_folder (`str` or `os.PathLike`, *optional*):
The path to offload weights if `device_map` contains the value `"disk"`.
offload_state_dict (`bool`, *optional*):
If `True`, temporarily offloads the CPU state dict to the hard drive to avoid running out of CPU RAM if
the weight of the CPU state dict + the biggest shard of the checkpoint does not fit. Defaults to `True`
when there is some disk offload.
low_cpu_mem_usage (`bool`, *optional*, defaults to `True` if torch version >= 1.9.0 else `False`):
Speed up model loading only loading the pretrained weights and not initializing the weights. This also
tries to not use more than 1x model size in CPU memory (including peak memory) while loading the model.
Only supported for PyTorch >= 1.9.0. If you are using an older version of PyTorch, setting this
argument to `True` will raise an error.
variant (`str`, *optional*):
Load weights from a specified `variant` filename such as `"fp16"` or `"ema"`. This is ignored when
loading `from_flax`.
use_safetensors (`bool`, *optional*, defaults to `None`):
If set to `None`, the `safetensors` weights are downloaded if they're available **and** if the
`safetensors` library is installed. If set to `True`, the model is forcibly loaded from `safetensors`
weights. If set to `False`, `safetensors` weights are not loaded.
<Tip>
To use private or [gated models](https://huggingface.co/docs/hub/models-gated#gated-models), log-in with
`huggingface-cli login`. You can also activate the special
["offline-mode"](https://huggingface.co/diffusers/installation.html#offline-mode) to use this method in a
firewalled environment.
</Tip>
Example:
```py
from diffusers import UNet2DConditionModel
unet = UNet2DConditionModel.from_pretrained("runwayml/stable-diffusion-v1-5", subfolder="unet")
```
If you get the error message below, you need to finetune the weights for your downstream task:
```bash
Some weights of UNet2DConditionModel were not initialized from the model checkpoint at runwayml/stable-diffusion-v1-5 and are newly initialized because the shapes did not match:
- conv_in.weight: found shape torch.Size([320, 4, 3, 3]) in the checkpoint and torch.Size([320, 9, 3, 3]) in the model instantiated
You should probably TRAIN this model on a down-stream task to be able to use it for predictions and inference.
```
"""
cache_dir = kwargs.pop("cache_dir", DIFFUSERS_CACHE)
ignore_mismatched_sizes = kwargs.pop("ignore_mismatched_sizes", False)
force_download = kwargs.pop("force_download", False)
from_flax = kwargs.pop("from_flax", False)
resume_download = kwargs.pop("resume_download", False)
proxies = kwargs.pop("proxies", None)
output_loading_info = kwargs.pop("output_loading_info", False)
local_files_only = kwargs.pop("local_files_only", HF_HUB_OFFLINE)
use_auth_token = kwargs.pop("use_auth_token", None)
revision = kwargs.pop("revision", None)
torch_dtype = kwargs.pop("torch_dtype", None)
subfolder = kwargs.pop("subfolder", None)
device_map = kwargs.pop("device_map", None)
max_memory = kwargs.pop("max_memory", None)
offload_folder = kwargs.pop("offload_folder", None)
offload_state_dict = kwargs.pop("offload_state_dict", False)
low_cpu_mem_usage = kwargs.pop("low_cpu_mem_usage", _LOW_CPU_MEM_USAGE_DEFAULT)
variant = kwargs.pop("variant", None)
use_safetensors = kwargs.pop("use_safetensors", None)
allow_pickle = False
if use_safetensors is None:
use_safetensors = True
allow_pickle = True
if low_cpu_mem_usage and not is_accelerate_available():
low_cpu_mem_usage = False
logger.warning(
"Cannot initialize model with low cpu memory usage because `accelerate` was not found in the"
" environment. Defaulting to `low_cpu_mem_usage=False`. It is strongly recommended to install"
" `accelerate` for faster and less memory-intense model loading. You can do so with: \n```\npip"
" install accelerate\n```\n."
)
if device_map is not None and not is_accelerate_available():
raise NotImplementedError(
"Loading and dispatching requires `accelerate`. Please make sure to install accelerate or set"
" `device_map=None`. You can install accelerate with `pip install accelerate`."
)
# Check if we can handle device_map and dispatching the weights
if device_map is not None and not is_torch_version(">=", "1.9.0"):
raise NotImplementedError(
"Loading and dispatching requires torch >= 1.9.0. Please either update your PyTorch version or set"
" `device_map=None`."
)
if low_cpu_mem_usage is True and not is_torch_version(">=", "1.9.0"):
raise NotImplementedError(
"Low memory initialization requires torch >= 1.9.0. Please either update your PyTorch version or set"
" `low_cpu_mem_usage=False`."
)
if low_cpu_mem_usage is False and device_map is not None:
raise ValueError(
f"You cannot set `low_cpu_mem_usage` to `False` while using device_map={device_map} for loading and"
" dispatching. Please make sure to set `low_cpu_mem_usage=True`."
)
# Load config if we don't provide a configuration
config_path = pretrained_model_name_or_path
user_agent = {
"diffusers": __version__,
"file_type": "model",
"framework": "pytorch",
}
# load config
config, unused_kwargs, commit_hash = cls.load_config(
config_path,
cache_dir=cache_dir,
return_unused_kwargs=True,
return_commit_hash=True,
force_download=force_download,
resume_download=resume_download,
proxies=proxies,
local_files_only=local_files_only,
use_auth_token=use_auth_token,
revision=revision,
subfolder=subfolder,
device_map=device_map,
max_memory=max_memory,
offload_folder=offload_folder,
offload_state_dict=offload_state_dict,
user_agent=user_agent,
**kwargs,
)
# load model
model_file = None
if from_flax:
model_file = _get_model_file(
pretrained_model_name_or_path,
weights_name=FLAX_WEIGHTS_NAME,
cache_dir=cache_dir,
force_download=force_download,
resume_download=resume_download,
proxies=proxies,
local_files_only=local_files_only,
use_auth_token=use_auth_token,
revision=revision,
subfolder=subfolder,
user_agent=user_agent,
commit_hash=commit_hash,
)
model = cls.from_config(config, **unused_kwargs)
# Convert the weights
from .modeling_pytorch_flax_utils import load_flax_checkpoint_in_pytorch_model
model = load_flax_checkpoint_in_pytorch_model(model, model_file)
else:
if use_safetensors:
try:
model_file = _get_model_file(
pretrained_model_name_or_path,
weights_name=_add_variant(SAFETENSORS_WEIGHTS_NAME, variant),
cache_dir=cache_dir,
force_download=force_download,
resume_download=resume_download,
proxies=proxies,
local_files_only=local_files_only,
use_auth_token=use_auth_token,
revision=revision,
subfolder=subfolder,
user_agent=user_agent,
commit_hash=commit_hash,
)
except IOError as e:
if not allow_pickle:
raise e
pass
if model_file is None:
model_file = _get_model_file(
pretrained_model_name_or_path,
weights_name=_add_variant(WEIGHTS_NAME, variant),
cache_dir=cache_dir,
force_download=force_download,
resume_download=resume_download,
proxies=proxies,
local_files_only=local_files_only,
use_auth_token=use_auth_token,
revision=revision,
subfolder=subfolder,
user_agent=user_agent,
commit_hash=commit_hash,
)
if low_cpu_mem_usage:
# Instantiate model with empty weights
with accelerate.init_empty_weights():
model = cls.from_config(config, **unused_kwargs)
# if device_map is None, load the state dict and move the params from meta device to the cpu
if device_map is None:
param_device = "cpu"
state_dict = load_state_dict(model_file, variant=variant)
model._convert_deprecated_attention_blocks(state_dict)
# move the params from meta device to cpu
missing_keys = set(model.state_dict().keys()) - set(state_dict.keys())
if len(missing_keys) > 0:
raise ValueError(
f"Cannot load {cls} from {pretrained_model_name_or_path} because the following keys are"
f" missing: \n {', '.join(missing_keys)}. \n Please make sure to pass"
" `low_cpu_mem_usage=False` and `device_map=None` if you want to randomly initialize"
" those weights or else make sure your checkpoint file is correct."
)
unexpected_keys = load_model_dict_into_meta(
model,
state_dict,
device=param_device,
dtype=torch_dtype,
model_name_or_path=pretrained_model_name_or_path,
)
if cls._keys_to_ignore_on_load_unexpected is not None:
for pat in cls._keys_to_ignore_on_load_unexpected:
unexpected_keys = [k for k in unexpected_keys if re.search(pat, k) is None]
if len(unexpected_keys) > 0:
logger.warn(
f"Some weights of the model checkpoint were not used when initializing {cls.__name__}: \n {[', '.join(unexpected_keys)]}"
)
else: # else let accelerate handle loading and dispatching.
# Load weights and dispatch according to the device_map
# by default the device_map is None and the weights are loaded on the CPU
try:
accelerate.load_checkpoint_and_dispatch(
model,
model_file,
device_map,
max_memory=max_memory,
offload_folder=offload_folder,
offload_state_dict=offload_state_dict,
dtype=torch_dtype,
)
except AttributeError as e:
# When using accelerate loading, we do not have the ability to load the state
# dict and rename the weight names manually. Additionally, accelerate skips
# torch loading conventions and directly writes into `module.{_buffers, _parameters}`
# (which look like they should be private variables?), so we can't use the standard hooks
# to rename parameters on load. We need to mimic the original weight names so the correct
# attributes are available. After we have loaded the weights, we convert the deprecated
# names to the new non-deprecated names. Then we _greatly encourage_ the user to convert
# the weights so we don't have to do this again.
if "'Attention' object has no attribute" in str(e):
logger.warn(
f"Taking `{str(e)}` while using `accelerate.load_checkpoint_and_dispatch` to mean {pretrained_model_name_or_path}"
" was saved with deprecated attention block weight names. We will load it with the deprecated attention block"
" names and convert them on the fly to the new attention block format. Please re-save the model after this conversion,"
" so we don't have to do the on the fly renaming in the future. If the model is from a hub checkpoint,"
" please also re-upload it or open a PR on the original repository."
)
model._temp_convert_self_to_deprecated_attention_blocks()
accelerate.load_checkpoint_and_dispatch(
model,
model_file,
device_map,
max_memory=max_memory,
offload_folder=offload_folder,
offload_state_dict=offload_state_dict,
dtype=torch_dtype,
)
model._undo_temp_convert_self_to_deprecated_attention_blocks()
else:
raise e
loading_info = {
"missing_keys": [],
"unexpected_keys": [],
"mismatched_keys": [],
"error_msgs": [],
}
else:
model = cls.from_config(config, **unused_kwargs)
state_dict = load_state_dict(model_file, variant=variant)
model._convert_deprecated_attention_blocks(state_dict)
model, missing_keys, unexpected_keys, mismatched_keys, error_msgs = cls._load_pretrained_model(
model,
state_dict,
model_file,
pretrained_model_name_or_path,
ignore_mismatched_sizes=ignore_mismatched_sizes,
)
loading_info = {
"missing_keys": missing_keys,
"unexpected_keys": unexpected_keys,
"mismatched_keys": mismatched_keys,
"error_msgs": error_msgs,
}
if torch_dtype is not None and not isinstance(torch_dtype, torch.dtype):
raise ValueError(
f"{torch_dtype} needs to be of type `torch.dtype`, e.g. `torch.float16`, but is {type(torch_dtype)}."
)
elif torch_dtype is not None:
model = model.to(torch_dtype)
model.register_to_config(_name_or_path=pretrained_model_name_or_path)
# Set model in evaluation mode to deactivate DropOut modules by default
model.eval()
if output_loading_info:
return model, loading_info
return model
@classmethod
def _load_pretrained_model(
cls,
model,
state_dict,
resolved_archive_file,
pretrained_model_name_or_path,
ignore_mismatched_sizes=False,
):
# Retrieve missing & unexpected_keys
model_state_dict = model.state_dict()
loaded_keys = list(state_dict.keys())
expected_keys = list(model_state_dict.keys())
original_loaded_keys = loaded_keys
missing_keys = list(set(expected_keys) - set(loaded_keys))
unexpected_keys = list(set(loaded_keys) - set(expected_keys))
# Make sure we are able to load base models as well as derived models (with heads)
model_to_load = model
def _find_mismatched_keys(
state_dict,
model_state_dict,
loaded_keys,
ignore_mismatched_sizes,
):
mismatched_keys = []
if ignore_mismatched_sizes:
for checkpoint_key in loaded_keys:
model_key = checkpoint_key
if (
model_key in model_state_dict
and state_dict[checkpoint_key].shape != model_state_dict[model_key].shape
):
mismatched_keys.append(
(checkpoint_key, state_dict[checkpoint_key].shape, model_state_dict[model_key].shape)
)
del state_dict[checkpoint_key]
return mismatched_keys
if state_dict is not None:
# Whole checkpoint
mismatched_keys = _find_mismatched_keys(
state_dict,
model_state_dict,
original_loaded_keys,
ignore_mismatched_sizes,
)
error_msgs = _load_state_dict_into_model(model_to_load, state_dict)
if len(error_msgs) > 0:
error_msg = "\n\t".join(error_msgs)
if "size mismatch" in error_msg:
error_msg += (
"\n\tYou may consider adding `ignore_mismatched_sizes=True` in the model `from_pretrained` method."
)
raise RuntimeError(f"Error(s) in loading state_dict for {model.__class__.__name__}:\n\t{error_msg}")
if len(unexpected_keys) > 0:
logger.warning(
f"Some weights of the model checkpoint at {pretrained_model_name_or_path} were not used when"
f" initializing {model.__class__.__name__}: {unexpected_keys}\n- This IS expected if you are"
f" initializing {model.__class__.__name__} from the checkpoint of a model trained on another task"
" or with another architecture (e.g. initializing a BertForSequenceClassification model from a"
" BertForPreTraining model).\n- This IS NOT expected if you are initializing"
f" {model.__class__.__name__} from the checkpoint of a model that you expect to be exactly"
" identical (initializing a BertForSequenceClassification model from a"
" BertForSequenceClassification model)."
)
else:
logger.info(f"All model checkpoint weights were used when initializing {model.__class__.__name__}.\n")
if len(missing_keys) > 0:
logger.warning(
f"Some weights of {model.__class__.__name__} were not initialized from the model checkpoint at"
f" {pretrained_model_name_or_path} and are newly initialized: {missing_keys}\nYou should probably"
" TRAIN this model on a down-stream task to be able to use it for predictions and inference."
)
elif len(mismatched_keys) == 0:
logger.info(
f"All the weights of {model.__class__.__name__} were initialized from the model checkpoint at"
f" {pretrained_model_name_or_path}.\nIf your task is similar to the task the model of the"
f" checkpoint was trained on, you can already use {model.__class__.__name__} for predictions"
" without further training."
)
if len(mismatched_keys) > 0:
mismatched_warning = "\n".join(
[
f"- {key}: found shape {shape1} in the checkpoint and {shape2} in the model instantiated"
for key, shape1, shape2 in mismatched_keys
]
)
logger.warning(
f"Some weights of {model.__class__.__name__} were not initialized from the model checkpoint at"
f" {pretrained_model_name_or_path} and are newly initialized because the shapes did not"
f" match:\n{mismatched_warning}\nYou should probably TRAIN this model on a down-stream task to be"
" able to use it for predictions and inference."
)
return model, missing_keys, unexpected_keys, mismatched_keys, error_msgs
@property
def device(self) -> device:
"""
`torch.device`: The device on which the module is (assuming that all the module parameters are on the same
device).
"""
return get_parameter_device(self)
@property
def dtype(self) -> torch.dtype:
"""
`torch.dtype`: The dtype of the module (assuming that all the module parameters have the same dtype).
"""
return get_parameter_dtype(self)
def num_parameters(self, only_trainable: bool = False, exclude_embeddings: bool = False) -> int:
"""
Get number of (trainable or non-embedding) parameters in the module.
Args:
only_trainable (`bool`, *optional*, defaults to `False`):
Whether or not to return only the number of trainable parameters.
exclude_embeddings (`bool`, *optional*, defaults to `False`):
Whether or not to return only the number of non-embedding parameters.
Returns:
`int`: The number of parameters.
Example:
```py
from diffusers import UNet2DConditionModel
model_id = "runwayml/stable-diffusion-v1-5"
unet = UNet2DConditionModel.from_pretrained(model_id, subfolder="unet")
unet.num_parameters(only_trainable=True)
859520964
```
"""
if exclude_embeddings:
embedding_param_names = [
f"{name}.weight"
for name, module_type in self.named_modules()
if isinstance(module_type, torch.nn.Embedding)
]
non_embedding_parameters = [
parameter for name, parameter in self.named_parameters() if name not in embedding_param_names
]
return sum(p.numel() for p in non_embedding_parameters if p.requires_grad or not only_trainable)
else:
return sum(p.numel() for p in self.parameters() if p.requires_grad or not only_trainable)
def _convert_deprecated_attention_blocks(self, state_dict):
deprecated_attention_block_paths = []
def recursive_find_attn_block(name, module):
if hasattr(module, "_from_deprecated_attn_block") and module._from_deprecated_attn_block:
deprecated_attention_block_paths.append(name)
for sub_name, sub_module in module.named_children():
sub_name = sub_name if name == "" else f"{name}.{sub_name}"
recursive_find_attn_block(sub_name, sub_module)
recursive_find_attn_block("", self)
# NOTE: we have to check if the deprecated parameters are in the state dict
# because it is possible we are loading from a state dict that was already
# converted
for path in deprecated_attention_block_paths:
# group_norm path stays the same
# query -> to_q
if f"{path}.query.weight" in state_dict:
state_dict[f"{path}.to_q.weight"] = state_dict.pop(f"{path}.query.weight")
if f"{path}.query.bias" in state_dict:
state_dict[f"{path}.to_q.bias"] = state_dict.pop(f"{path}.query.bias")
# key -> to_k
if f"{path}.key.weight" in state_dict:
state_dict[f"{path}.to_k.weight"] = state_dict.pop(f"{path}.key.weight")
if f"{path}.key.bias" in state_dict:
state_dict[f"{path}.to_k.bias"] = state_dict.pop(f"{path}.key.bias")
# value -> to_v
if f"{path}.value.weight" in state_dict:
state_dict[f"{path}.to_v.weight"] = state_dict.pop(f"{path}.value.weight")
if f"{path}.value.bias" in state_dict:
state_dict[f"{path}.to_v.bias"] = state_dict.pop(f"{path}.value.bias")
# proj_attn -> to_out.0
if f"{path}.proj_attn.weight" in state_dict:
state_dict[f"{path}.to_out.0.weight"] = state_dict.pop(f"{path}.proj_attn.weight")
if f"{path}.proj_attn.bias" in state_dict:
state_dict[f"{path}.to_out.0.bias"] = state_dict.pop(f"{path}.proj_attn.bias")
def _temp_convert_self_to_deprecated_attention_blocks(self):
deprecated_attention_block_modules = []
def recursive_find_attn_block(module):
if hasattr(module, "_from_deprecated_attn_block") and module._from_deprecated_attn_block:
deprecated_attention_block_modules.append(module)
for sub_module in module.children():
recursive_find_attn_block(sub_module)
recursive_find_attn_block(self)
for module in deprecated_attention_block_modules:
module.query = module.to_q
module.key = module.to_k
module.value = module.to_v
module.proj_attn = module.to_out[0]
# We don't _have_ to delete the old attributes, but it's helpful to ensure
# that _all_ the weights are loaded into the new attributes and we're not
# making an incorrect assumption that this model should be converted when
# it really shouldn't be.
del module.to_q
del module.to_k
del module.to_v
del module.to_out
def _undo_temp_convert_self_to_deprecated_attention_blocks(self):
deprecated_attention_block_modules = []
def recursive_find_attn_block(module):
if hasattr(module, "_from_deprecated_attn_block") and module._from_deprecated_attn_block:
deprecated_attention_block_modules.append(module)
for sub_module in module.children():
recursive_find_attn_block(sub_module)
recursive_find_attn_block(self)
for module in deprecated_attention_block_modules:
module.to_q = module.query
module.to_k = module.key
module.to_v = module.value
module.to_out = nn.ModuleList([module.proj_attn, nn.Dropout(module.dropout)])
del module.query
del module.key
del module.value
del module.proj_attn
| diffusers-main | src/diffusers/models/modeling_utils.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import torch
import torch.nn as nn
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from .embeddings import GaussianFourierProjection, TimestepEmbedding, Timesteps
from .modeling_utils import ModelMixin
from .unet_2d_blocks import UNetMidBlock2D, get_down_block, get_up_block
@dataclass
class UNet2DOutput(BaseOutput):
"""
The output of [`UNet2DModel`].
Args:
sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`):
The hidden states output from the last layer of the model.
"""
sample: torch.FloatTensor
class UNet2DModel(ModelMixin, ConfigMixin):
r"""
A 2D UNet model that takes a noisy sample and a timestep and returns a sample shaped output.
This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
for all models (such as downloading or saving).
Parameters:
sample_size (`int` or `Tuple[int, int]`, *optional*, defaults to `None`):
Height and width of input/output sample. Dimensions must be a multiple of `2 ** (len(block_out_channels) -
1)`.
in_channels (`int`, *optional*, defaults to 3): Number of channels in the input sample.
out_channels (`int`, *optional*, defaults to 3): Number of channels in the output.
center_input_sample (`bool`, *optional*, defaults to `False`): Whether to center the input sample.
time_embedding_type (`str`, *optional*, defaults to `"positional"`): Type of time embedding to use.
freq_shift (`int`, *optional*, defaults to 0): Frequency shift for Fourier time embedding.
flip_sin_to_cos (`bool`, *optional*, defaults to `True`):
Whether to flip sin to cos for Fourier time embedding.
down_block_types (`Tuple[str]`, *optional*, defaults to `("DownBlock2D", "AttnDownBlock2D", "AttnDownBlock2D", "AttnDownBlock2D")`):
Tuple of downsample block types.
mid_block_type (`str`, *optional*, defaults to `"UNetMidBlock2D"`):
Block type for middle of UNet, it can be either `UNetMidBlock2D` or `UnCLIPUNetMidBlock2D`.
up_block_types (`Tuple[str]`, *optional*, defaults to `("AttnUpBlock2D", "AttnUpBlock2D", "AttnUpBlock2D", "UpBlock2D")`):
Tuple of upsample block types.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(224, 448, 672, 896)`):
Tuple of block output channels.
layers_per_block (`int`, *optional*, defaults to `2`): The number of layers per block.
mid_block_scale_factor (`float`, *optional*, defaults to `1`): The scale factor for the mid block.
downsample_padding (`int`, *optional*, defaults to `1`): The padding for the downsample convolution.
downsample_type (`str`, *optional*, defaults to `conv`):
The downsample type for downsampling layers. Choose between "conv" and "resnet"
upsample_type (`str`, *optional*, defaults to `conv`):
The upsample type for upsampling layers. Choose between "conv" and "resnet"
dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
attention_head_dim (`int`, *optional*, defaults to `8`): The attention head dimension.
norm_num_groups (`int`, *optional*, defaults to `32`): The number of groups for normalization.
attn_norm_num_groups (`int`, *optional*, defaults to `None`):
If set to an integer, a group norm layer will be created in the mid block's [`Attention`] layer with the
given number of groups. If left as `None`, the group norm layer will only be created if
`resnet_time_scale_shift` is set to `default`, and if created will have `norm_num_groups` groups.
norm_eps (`float`, *optional*, defaults to `1e-5`): The epsilon for normalization.
resnet_time_scale_shift (`str`, *optional*, defaults to `"default"`): Time scale shift config
for ResNet blocks (see [`~models.resnet.ResnetBlock2D`]). Choose from `default` or `scale_shift`.
class_embed_type (`str`, *optional*, defaults to `None`):
The type of class embedding to use which is ultimately summed with the time embeddings. Choose from `None`,
`"timestep"`, or `"identity"`.
num_class_embeds (`int`, *optional*, defaults to `None`):
Input dimension of the learnable embedding matrix to be projected to `time_embed_dim` when performing class
conditioning with `class_embed_type` equal to `None`.
"""
@register_to_config
def __init__(
self,
sample_size: Optional[Union[int, Tuple[int, int]]] = None,
in_channels: int = 3,
out_channels: int = 3,
center_input_sample: bool = False,
time_embedding_type: str = "positional",
freq_shift: int = 0,
flip_sin_to_cos: bool = True,
down_block_types: Tuple[str] = ("DownBlock2D", "AttnDownBlock2D", "AttnDownBlock2D", "AttnDownBlock2D"),
up_block_types: Tuple[str] = ("AttnUpBlock2D", "AttnUpBlock2D", "AttnUpBlock2D", "UpBlock2D"),
block_out_channels: Tuple[int] = (224, 448, 672, 896),
layers_per_block: int = 2,
mid_block_scale_factor: float = 1,
downsample_padding: int = 1,
downsample_type: str = "conv",
upsample_type: str = "conv",
dropout: float = 0.0,
act_fn: str = "silu",
attention_head_dim: Optional[int] = 8,
norm_num_groups: int = 32,
attn_norm_num_groups: Optional[int] = None,
norm_eps: float = 1e-5,
resnet_time_scale_shift: str = "default",
add_attention: bool = True,
class_embed_type: Optional[str] = None,
num_class_embeds: Optional[int] = None,
):
super().__init__()
self.sample_size = sample_size
time_embed_dim = block_out_channels[0] * 4
# Check inputs
if len(down_block_types) != len(up_block_types):
raise ValueError(
f"Must provide the same number of `down_block_types` as `up_block_types`. `down_block_types`: {down_block_types}. `up_block_types`: {up_block_types}."
)
if len(block_out_channels) != len(down_block_types):
raise ValueError(
f"Must provide the same number of `block_out_channels` as `down_block_types`. `block_out_channels`: {block_out_channels}. `down_block_types`: {down_block_types}."
)
# input
self.conv_in = nn.Conv2d(in_channels, block_out_channels[0], kernel_size=3, padding=(1, 1))
# time
if time_embedding_type == "fourier":
self.time_proj = GaussianFourierProjection(embedding_size=block_out_channels[0], scale=16)
timestep_input_dim = 2 * block_out_channels[0]
elif time_embedding_type == "positional":
self.time_proj = Timesteps(block_out_channels[0], flip_sin_to_cos, freq_shift)
timestep_input_dim = block_out_channels[0]
self.time_embedding = TimestepEmbedding(timestep_input_dim, time_embed_dim)
# class embedding
if class_embed_type is None and num_class_embeds is not None:
self.class_embedding = nn.Embedding(num_class_embeds, time_embed_dim)
elif class_embed_type == "timestep":
self.class_embedding = TimestepEmbedding(timestep_input_dim, time_embed_dim)
elif class_embed_type == "identity":
self.class_embedding = nn.Identity(time_embed_dim, time_embed_dim)
else:
self.class_embedding = None
self.down_blocks = nn.ModuleList([])
self.mid_block = None
self.up_blocks = nn.ModuleList([])
# down
output_channel = block_out_channels[0]
for i, down_block_type in enumerate(down_block_types):
input_channel = output_channel
output_channel = block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
down_block = get_down_block(
down_block_type,
num_layers=layers_per_block,
in_channels=input_channel,
out_channels=output_channel,
temb_channels=time_embed_dim,
add_downsample=not is_final_block,
resnet_eps=norm_eps,
resnet_act_fn=act_fn,
resnet_groups=norm_num_groups,
attention_head_dim=attention_head_dim if attention_head_dim is not None else output_channel,
downsample_padding=downsample_padding,
resnet_time_scale_shift=resnet_time_scale_shift,
downsample_type=downsample_type,
dropout=dropout,
)
self.down_blocks.append(down_block)
# mid
self.mid_block = UNetMidBlock2D(
in_channels=block_out_channels[-1],
temb_channels=time_embed_dim,
dropout=dropout,
resnet_eps=norm_eps,
resnet_act_fn=act_fn,
output_scale_factor=mid_block_scale_factor,
resnet_time_scale_shift=resnet_time_scale_shift,
attention_head_dim=attention_head_dim if attention_head_dim is not None else block_out_channels[-1],
resnet_groups=norm_num_groups,
attn_groups=attn_norm_num_groups,
add_attention=add_attention,
)
# up
reversed_block_out_channels = list(reversed(block_out_channels))
output_channel = reversed_block_out_channels[0]
for i, up_block_type in enumerate(up_block_types):
prev_output_channel = output_channel
output_channel = reversed_block_out_channels[i]
input_channel = reversed_block_out_channels[min(i + 1, len(block_out_channels) - 1)]
is_final_block = i == len(block_out_channels) - 1
up_block = get_up_block(
up_block_type,
num_layers=layers_per_block + 1,
in_channels=input_channel,
out_channels=output_channel,
prev_output_channel=prev_output_channel,
temb_channels=time_embed_dim,
add_upsample=not is_final_block,
resnet_eps=norm_eps,
resnet_act_fn=act_fn,
resnet_groups=norm_num_groups,
attention_head_dim=attention_head_dim if attention_head_dim is not None else output_channel,
resnet_time_scale_shift=resnet_time_scale_shift,
upsample_type=upsample_type,
dropout=dropout,
)
self.up_blocks.append(up_block)
prev_output_channel = output_channel
# out
num_groups_out = norm_num_groups if norm_num_groups is not None else min(block_out_channels[0] // 4, 32)
self.conv_norm_out = nn.GroupNorm(num_channels=block_out_channels[0], num_groups=num_groups_out, eps=norm_eps)
self.conv_act = nn.SiLU()
self.conv_out = nn.Conv2d(block_out_channels[0], out_channels, kernel_size=3, padding=1)
def forward(
self,
sample: torch.FloatTensor,
timestep: Union[torch.Tensor, float, int],
class_labels: Optional[torch.Tensor] = None,
return_dict: bool = True,
) -> Union[UNet2DOutput, Tuple]:
r"""
The [`UNet2DModel`] forward method.
Args:
sample (`torch.FloatTensor`):
The noisy input tensor with the following shape `(batch, channel, height, width)`.
timestep (`torch.FloatTensor` or `float` or `int`): The number of timesteps to denoise an input.
class_labels (`torch.FloatTensor`, *optional*, defaults to `None`):
Optional class labels for conditioning. Their embeddings will be summed with the timestep embeddings.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.unet_2d.UNet2DOutput`] instead of a plain tuple.
Returns:
[`~models.unet_2d.UNet2DOutput`] or `tuple`:
If `return_dict` is True, an [`~models.unet_2d.UNet2DOutput`] is returned, otherwise a `tuple` is
returned where the first element is the sample tensor.
"""
# 0. center input if necessary
if self.config.center_input_sample:
sample = 2 * sample - 1.0
# 1. time
timesteps = timestep
if not torch.is_tensor(timesteps):
timesteps = torch.tensor([timesteps], dtype=torch.long, device=sample.device)
elif torch.is_tensor(timesteps) and len(timesteps.shape) == 0:
timesteps = timesteps[None].to(sample.device)
# broadcast to batch dimension in a way that's compatible with ONNX/Core ML
timesteps = timesteps * torch.ones(sample.shape[0], dtype=timesteps.dtype, device=timesteps.device)
t_emb = self.time_proj(timesteps)
# timesteps does not contain any weights and will always return f32 tensors
# but time_embedding might actually be running in fp16. so we need to cast here.
# there might be better ways to encapsulate this.
t_emb = t_emb.to(dtype=self.dtype)
emb = self.time_embedding(t_emb)
if self.class_embedding is not None:
if class_labels is None:
raise ValueError("class_labels should be provided when doing class conditioning")
if self.config.class_embed_type == "timestep":
class_labels = self.time_proj(class_labels)
class_emb = self.class_embedding(class_labels).to(dtype=self.dtype)
emb = emb + class_emb
# 2. pre-process
skip_sample = sample
sample = self.conv_in(sample)
# 3. down
down_block_res_samples = (sample,)
for downsample_block in self.down_blocks:
if hasattr(downsample_block, "skip_conv"):
sample, res_samples, skip_sample = downsample_block(
hidden_states=sample, temb=emb, skip_sample=skip_sample
)
else:
sample, res_samples = downsample_block(hidden_states=sample, temb=emb)
down_block_res_samples += res_samples
# 4. mid
sample = self.mid_block(sample, emb)
# 5. up
skip_sample = None
for upsample_block in self.up_blocks:
res_samples = down_block_res_samples[-len(upsample_block.resnets) :]
down_block_res_samples = down_block_res_samples[: -len(upsample_block.resnets)]
if hasattr(upsample_block, "skip_conv"):
sample, skip_sample = upsample_block(sample, res_samples, emb, skip_sample)
else:
sample = upsample_block(sample, res_samples, emb)
# 6. post-process
sample = self.conv_norm_out(sample)
sample = self.conv_act(sample)
sample = self.conv_out(sample)
if skip_sample is not None:
sample += skip_sample
if self.config.time_embedding_type == "fourier":
timesteps = timesteps.reshape((sample.shape[0], *([1] * len(sample.shape[1:]))))
sample = sample / timesteps
if not return_dict:
return (sample,)
return UNet2DOutput(sample=sample)
| diffusers-main | src/diffusers/models/unet_2d.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import flax.linen as nn
import jax.numpy as jnp
from .attention_flax import FlaxTransformer2DModel
from .resnet_flax import FlaxDownsample2D, FlaxResnetBlock2D, FlaxUpsample2D
class FlaxCrossAttnDownBlock2D(nn.Module):
r"""
Cross Attention 2D Downsizing block - original architecture from Unet transformers:
https://arxiv.org/abs/2103.06104
Parameters:
in_channels (:obj:`int`):
Input channels
out_channels (:obj:`int`):
Output channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of attention blocks layers
num_attention_heads (:obj:`int`, *optional*, defaults to 1):
Number of attention heads of each spatial transformer block
add_downsample (:obj:`bool`, *optional*, defaults to `True`):
Whether to add downsampling layer before each final output
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`):
enable memory efficient attention https://arxiv.org/abs/2112.05682
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
out_channels: int
dropout: float = 0.0
num_layers: int = 1
num_attention_heads: int = 1
add_downsample: bool = True
use_linear_projection: bool = False
only_cross_attention: bool = False
use_memory_efficient_attention: bool = False
dtype: jnp.dtype = jnp.float32
def setup(self):
resnets = []
attentions = []
for i in range(self.num_layers):
in_channels = self.in_channels if i == 0 else self.out_channels
res_block = FlaxResnetBlock2D(
in_channels=in_channels,
out_channels=self.out_channels,
dropout_prob=self.dropout,
dtype=self.dtype,
)
resnets.append(res_block)
attn_block = FlaxTransformer2DModel(
in_channels=self.out_channels,
n_heads=self.num_attention_heads,
d_head=self.out_channels // self.num_attention_heads,
depth=1,
use_linear_projection=self.use_linear_projection,
only_cross_attention=self.only_cross_attention,
use_memory_efficient_attention=self.use_memory_efficient_attention,
dtype=self.dtype,
)
attentions.append(attn_block)
self.resnets = resnets
self.attentions = attentions
if self.add_downsample:
self.downsamplers_0 = FlaxDownsample2D(self.out_channels, dtype=self.dtype)
def __call__(self, hidden_states, temb, encoder_hidden_states, deterministic=True):
output_states = ()
for resnet, attn in zip(self.resnets, self.attentions):
hidden_states = resnet(hidden_states, temb, deterministic=deterministic)
hidden_states = attn(hidden_states, encoder_hidden_states, deterministic=deterministic)
output_states += (hidden_states,)
if self.add_downsample:
hidden_states = self.downsamplers_0(hidden_states)
output_states += (hidden_states,)
return hidden_states, output_states
class FlaxDownBlock2D(nn.Module):
r"""
Flax 2D downsizing block
Parameters:
in_channels (:obj:`int`):
Input channels
out_channels (:obj:`int`):
Output channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of attention blocks layers
add_downsample (:obj:`bool`, *optional*, defaults to `True`):
Whether to add downsampling layer before each final output
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
out_channels: int
dropout: float = 0.0
num_layers: int = 1
add_downsample: bool = True
dtype: jnp.dtype = jnp.float32
def setup(self):
resnets = []
for i in range(self.num_layers):
in_channels = self.in_channels if i == 0 else self.out_channels
res_block = FlaxResnetBlock2D(
in_channels=in_channels,
out_channels=self.out_channels,
dropout_prob=self.dropout,
dtype=self.dtype,
)
resnets.append(res_block)
self.resnets = resnets
if self.add_downsample:
self.downsamplers_0 = FlaxDownsample2D(self.out_channels, dtype=self.dtype)
def __call__(self, hidden_states, temb, deterministic=True):
output_states = ()
for resnet in self.resnets:
hidden_states = resnet(hidden_states, temb, deterministic=deterministic)
output_states += (hidden_states,)
if self.add_downsample:
hidden_states = self.downsamplers_0(hidden_states)
output_states += (hidden_states,)
return hidden_states, output_states
class FlaxCrossAttnUpBlock2D(nn.Module):
r"""
Cross Attention 2D Upsampling block - original architecture from Unet transformers:
https://arxiv.org/abs/2103.06104
Parameters:
in_channels (:obj:`int`):
Input channels
out_channels (:obj:`int`):
Output channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of attention blocks layers
num_attention_heads (:obj:`int`, *optional*, defaults to 1):
Number of attention heads of each spatial transformer block
add_upsample (:obj:`bool`, *optional*, defaults to `True`):
Whether to add upsampling layer before each final output
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`):
enable memory efficient attention https://arxiv.org/abs/2112.05682
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
out_channels: int
prev_output_channel: int
dropout: float = 0.0
num_layers: int = 1
num_attention_heads: int = 1
add_upsample: bool = True
use_linear_projection: bool = False
only_cross_attention: bool = False
use_memory_efficient_attention: bool = False
dtype: jnp.dtype = jnp.float32
def setup(self):
resnets = []
attentions = []
for i in range(self.num_layers):
res_skip_channels = self.in_channels if (i == self.num_layers - 1) else self.out_channels
resnet_in_channels = self.prev_output_channel if i == 0 else self.out_channels
res_block = FlaxResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=self.out_channels,
dropout_prob=self.dropout,
dtype=self.dtype,
)
resnets.append(res_block)
attn_block = FlaxTransformer2DModel(
in_channels=self.out_channels,
n_heads=self.num_attention_heads,
d_head=self.out_channels // self.num_attention_heads,
depth=1,
use_linear_projection=self.use_linear_projection,
only_cross_attention=self.only_cross_attention,
use_memory_efficient_attention=self.use_memory_efficient_attention,
dtype=self.dtype,
)
attentions.append(attn_block)
self.resnets = resnets
self.attentions = attentions
if self.add_upsample:
self.upsamplers_0 = FlaxUpsample2D(self.out_channels, dtype=self.dtype)
def __call__(self, hidden_states, res_hidden_states_tuple, temb, encoder_hidden_states, deterministic=True):
for resnet, attn in zip(self.resnets, self.attentions):
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = jnp.concatenate((hidden_states, res_hidden_states), axis=-1)
hidden_states = resnet(hidden_states, temb, deterministic=deterministic)
hidden_states = attn(hidden_states, encoder_hidden_states, deterministic=deterministic)
if self.add_upsample:
hidden_states = self.upsamplers_0(hidden_states)
return hidden_states
class FlaxUpBlock2D(nn.Module):
r"""
Flax 2D upsampling block
Parameters:
in_channels (:obj:`int`):
Input channels
out_channels (:obj:`int`):
Output channels
prev_output_channel (:obj:`int`):
Output channels from the previous block
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of attention blocks layers
add_downsample (:obj:`bool`, *optional*, defaults to `True`):
Whether to add downsampling layer before each final output
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
out_channels: int
prev_output_channel: int
dropout: float = 0.0
num_layers: int = 1
add_upsample: bool = True
dtype: jnp.dtype = jnp.float32
def setup(self):
resnets = []
for i in range(self.num_layers):
res_skip_channels = self.in_channels if (i == self.num_layers - 1) else self.out_channels
resnet_in_channels = self.prev_output_channel if i == 0 else self.out_channels
res_block = FlaxResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=self.out_channels,
dropout_prob=self.dropout,
dtype=self.dtype,
)
resnets.append(res_block)
self.resnets = resnets
if self.add_upsample:
self.upsamplers_0 = FlaxUpsample2D(self.out_channels, dtype=self.dtype)
def __call__(self, hidden_states, res_hidden_states_tuple, temb, deterministic=True):
for resnet in self.resnets:
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = jnp.concatenate((hidden_states, res_hidden_states), axis=-1)
hidden_states = resnet(hidden_states, temb, deterministic=deterministic)
if self.add_upsample:
hidden_states = self.upsamplers_0(hidden_states)
return hidden_states
class FlaxUNetMidBlock2DCrossAttn(nn.Module):
r"""
Cross Attention 2D Mid-level block - original architecture from Unet transformers: https://arxiv.org/abs/2103.06104
Parameters:
in_channels (:obj:`int`):
Input channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of attention blocks layers
num_attention_heads (:obj:`int`, *optional*, defaults to 1):
Number of attention heads of each spatial transformer block
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`):
enable memory efficient attention https://arxiv.org/abs/2112.05682
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
dropout: float = 0.0
num_layers: int = 1
num_attention_heads: int = 1
use_linear_projection: bool = False
use_memory_efficient_attention: bool = False
dtype: jnp.dtype = jnp.float32
def setup(self):
# there is always at least one resnet
resnets = [
FlaxResnetBlock2D(
in_channels=self.in_channels,
out_channels=self.in_channels,
dropout_prob=self.dropout,
dtype=self.dtype,
)
]
attentions = []
for _ in range(self.num_layers):
attn_block = FlaxTransformer2DModel(
in_channels=self.in_channels,
n_heads=self.num_attention_heads,
d_head=self.in_channels // self.num_attention_heads,
depth=1,
use_linear_projection=self.use_linear_projection,
use_memory_efficient_attention=self.use_memory_efficient_attention,
dtype=self.dtype,
)
attentions.append(attn_block)
res_block = FlaxResnetBlock2D(
in_channels=self.in_channels,
out_channels=self.in_channels,
dropout_prob=self.dropout,
dtype=self.dtype,
)
resnets.append(res_block)
self.resnets = resnets
self.attentions = attentions
def __call__(self, hidden_states, temb, encoder_hidden_states, deterministic=True):
hidden_states = self.resnets[0](hidden_states, temb)
for attn, resnet in zip(self.attentions, self.resnets[1:]):
hidden_states = attn(hidden_states, encoder_hidden_states, deterministic=deterministic)
hidden_states = resnet(hidden_states, temb, deterministic=deterministic)
return hidden_states
| diffusers-main | src/diffusers/models/unet_2d_blocks_flax.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
import flax.linen as nn
import jax.numpy as jnp
def get_sinusoidal_embeddings(
timesteps: jnp.ndarray,
embedding_dim: int,
freq_shift: float = 1,
min_timescale: float = 1,
max_timescale: float = 1.0e4,
flip_sin_to_cos: bool = False,
scale: float = 1.0,
) -> jnp.ndarray:
"""Returns the positional encoding (same as Tensor2Tensor).
Args:
timesteps: a 1-D Tensor of N indices, one per batch element.
These may be fractional.
embedding_dim: The number of output channels.
min_timescale: The smallest time unit (should probably be 0.0).
max_timescale: The largest time unit.
Returns:
a Tensor of timing signals [N, num_channels]
"""
assert timesteps.ndim == 1, "Timesteps should be a 1d-array"
assert embedding_dim % 2 == 0, f"Embedding dimension {embedding_dim} should be even"
num_timescales = float(embedding_dim // 2)
log_timescale_increment = math.log(max_timescale / min_timescale) / (num_timescales - freq_shift)
inv_timescales = min_timescale * jnp.exp(jnp.arange(num_timescales, dtype=jnp.float32) * -log_timescale_increment)
emb = jnp.expand_dims(timesteps, 1) * jnp.expand_dims(inv_timescales, 0)
# scale embeddings
scaled_time = scale * emb
if flip_sin_to_cos:
signal = jnp.concatenate([jnp.cos(scaled_time), jnp.sin(scaled_time)], axis=1)
else:
signal = jnp.concatenate([jnp.sin(scaled_time), jnp.cos(scaled_time)], axis=1)
signal = jnp.reshape(signal, [jnp.shape(timesteps)[0], embedding_dim])
return signal
class FlaxTimestepEmbedding(nn.Module):
r"""
Time step Embedding Module. Learns embeddings for input time steps.
Args:
time_embed_dim (`int`, *optional*, defaults to `32`):
Time step embedding dimension
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
time_embed_dim: int = 32
dtype: jnp.dtype = jnp.float32
@nn.compact
def __call__(self, temb):
temb = nn.Dense(self.time_embed_dim, dtype=self.dtype, name="linear_1")(temb)
temb = nn.silu(temb)
temb = nn.Dense(self.time_embed_dim, dtype=self.dtype, name="linear_2")(temb)
return temb
class FlaxTimesteps(nn.Module):
r"""
Wrapper Module for sinusoidal Time step Embeddings as described in https://arxiv.org/abs/2006.11239
Args:
dim (`int`, *optional*, defaults to `32`):
Time step embedding dimension
"""
dim: int = 32
flip_sin_to_cos: bool = False
freq_shift: float = 1
@nn.compact
def __call__(self, timesteps):
return get_sinusoidal_embeddings(
timesteps, embedding_dim=self.dim, flip_sin_to_cos=self.flip_sin_to_cos, freq_shift=self.freq_shift
)
| diffusers-main | src/diffusers/models/embeddings_flax.py |
# Copyright 2023 Alibaba DAMO-VILAB and The HuggingFace Team. All rights reserved.
# Copyright 2023 The ModelScope Team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Any, Dict, List, Optional, Tuple, Union
import torch
import torch.nn as nn
import torch.utils.checkpoint
from ..configuration_utils import ConfigMixin, register_to_config
from ..loaders import UNet2DConditionLoadersMixin
from ..utils import BaseOutput, logging
from .attention_processor import (
ADDED_KV_ATTENTION_PROCESSORS,
CROSS_ATTENTION_PROCESSORS,
AttentionProcessor,
AttnAddedKVProcessor,
AttnProcessor,
)
from .embeddings import TimestepEmbedding, Timesteps
from .modeling_utils import ModelMixin
from .transformer_temporal import TransformerTemporalModel
from .unet_3d_blocks import (
CrossAttnDownBlock3D,
CrossAttnUpBlock3D,
DownBlock3D,
UNetMidBlock3DCrossAttn,
UpBlock3D,
get_down_block,
get_up_block,
)
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
@dataclass
class UNet3DConditionOutput(BaseOutput):
"""
The output of [`UNet3DConditionModel`].
Args:
sample (`torch.FloatTensor` of shape `(batch_size, num_frames, num_channels, height, width)`):
The hidden states output conditioned on `encoder_hidden_states` input. Output of last layer of model.
"""
sample: torch.FloatTensor
class UNet3DConditionModel(ModelMixin, ConfigMixin, UNet2DConditionLoadersMixin):
r"""
A conditional 3D UNet model that takes a noisy sample, conditional state, and a timestep and returns a sample
shaped output.
This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
for all models (such as downloading or saving).
Parameters:
sample_size (`int` or `Tuple[int, int]`, *optional*, defaults to `None`):
Height and width of input/output sample.
in_channels (`int`, *optional*, defaults to 4): The number of channels in the input sample.
out_channels (`int`, *optional*, defaults to 4): The number of channels in the output.
down_block_types (`Tuple[str]`, *optional*, defaults to `("CrossAttnDownBlock2D", "CrossAttnDownBlock2D", "CrossAttnDownBlock2D", "DownBlock2D")`):
The tuple of downsample blocks to use.
up_block_types (`Tuple[str]`, *optional*, defaults to `("UpBlock2D", "CrossAttnUpBlock2D", "CrossAttnUpBlock2D", "CrossAttnUpBlock2D")`):
The tuple of upsample blocks to use.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(320, 640, 1280, 1280)`):
The tuple of output channels for each block.
layers_per_block (`int`, *optional*, defaults to 2): The number of layers per block.
downsample_padding (`int`, *optional*, defaults to 1): The padding to use for the downsampling convolution.
mid_block_scale_factor (`float`, *optional*, defaults to 1.0): The scale factor to use for the mid block.
act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
norm_num_groups (`int`, *optional*, defaults to 32): The number of groups to use for the normalization.
If `None`, normalization and activation layers is skipped in post-processing.
norm_eps (`float`, *optional*, defaults to 1e-5): The epsilon to use for the normalization.
cross_attention_dim (`int`, *optional*, defaults to 1280): The dimension of the cross attention features.
attention_head_dim (`int`, *optional*, defaults to 8): The dimension of the attention heads.
num_attention_heads (`int`, *optional*): The number of attention heads.
"""
_supports_gradient_checkpointing = False
@register_to_config
def __init__(
self,
sample_size: Optional[int] = None,
in_channels: int = 4,
out_channels: int = 4,
down_block_types: Tuple[str] = (
"CrossAttnDownBlock3D",
"CrossAttnDownBlock3D",
"CrossAttnDownBlock3D",
"DownBlock3D",
),
up_block_types: Tuple[str] = ("UpBlock3D", "CrossAttnUpBlock3D", "CrossAttnUpBlock3D", "CrossAttnUpBlock3D"),
block_out_channels: Tuple[int] = (320, 640, 1280, 1280),
layers_per_block: int = 2,
downsample_padding: int = 1,
mid_block_scale_factor: float = 1,
act_fn: str = "silu",
norm_num_groups: Optional[int] = 32,
norm_eps: float = 1e-5,
cross_attention_dim: int = 1024,
attention_head_dim: Union[int, Tuple[int]] = 64,
num_attention_heads: Optional[Union[int, Tuple[int]]] = None,
):
super().__init__()
self.sample_size = sample_size
if num_attention_heads is not None:
raise NotImplementedError(
"At the moment it is not possible to define the number of attention heads via `num_attention_heads` because of a naming issue as described in https://github.com/huggingface/diffusers/issues/2011#issuecomment-1547958131. Passing `num_attention_heads` will only be supported in diffusers v0.19."
)
# If `num_attention_heads` is not defined (which is the case for most models)
# it will default to `attention_head_dim`. This looks weird upon first reading it and it is.
# The reason for this behavior is to correct for incorrectly named variables that were introduced
# when this library was created. The incorrect naming was only discovered much later in https://github.com/huggingface/diffusers/issues/2011#issuecomment-1547958131
# Changing `attention_head_dim` to `num_attention_heads` for 40,000+ configurations is too backwards breaking
# which is why we correct for the naming here.
num_attention_heads = num_attention_heads or attention_head_dim
# Check inputs
if len(down_block_types) != len(up_block_types):
raise ValueError(
f"Must provide the same number of `down_block_types` as `up_block_types`. `down_block_types`: {down_block_types}. `up_block_types`: {up_block_types}."
)
if len(block_out_channels) != len(down_block_types):
raise ValueError(
f"Must provide the same number of `block_out_channels` as `down_block_types`. `block_out_channels`: {block_out_channels}. `down_block_types`: {down_block_types}."
)
if not isinstance(num_attention_heads, int) and len(num_attention_heads) != len(down_block_types):
raise ValueError(
f"Must provide the same number of `num_attention_heads` as `down_block_types`. `num_attention_heads`: {num_attention_heads}. `down_block_types`: {down_block_types}."
)
# input
conv_in_kernel = 3
conv_out_kernel = 3
conv_in_padding = (conv_in_kernel - 1) // 2
self.conv_in = nn.Conv2d(
in_channels, block_out_channels[0], kernel_size=conv_in_kernel, padding=conv_in_padding
)
# time
time_embed_dim = block_out_channels[0] * 4
self.time_proj = Timesteps(block_out_channels[0], True, 0)
timestep_input_dim = block_out_channels[0]
self.time_embedding = TimestepEmbedding(
timestep_input_dim,
time_embed_dim,
act_fn=act_fn,
)
self.transformer_in = TransformerTemporalModel(
num_attention_heads=8,
attention_head_dim=attention_head_dim,
in_channels=block_out_channels[0],
num_layers=1,
)
# class embedding
self.down_blocks = nn.ModuleList([])
self.up_blocks = nn.ModuleList([])
if isinstance(num_attention_heads, int):
num_attention_heads = (num_attention_heads,) * len(down_block_types)
# down
output_channel = block_out_channels[0]
for i, down_block_type in enumerate(down_block_types):
input_channel = output_channel
output_channel = block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
down_block = get_down_block(
down_block_type,
num_layers=layers_per_block,
in_channels=input_channel,
out_channels=output_channel,
temb_channels=time_embed_dim,
add_downsample=not is_final_block,
resnet_eps=norm_eps,
resnet_act_fn=act_fn,
resnet_groups=norm_num_groups,
cross_attention_dim=cross_attention_dim,
num_attention_heads=num_attention_heads[i],
downsample_padding=downsample_padding,
dual_cross_attention=False,
)
self.down_blocks.append(down_block)
# mid
self.mid_block = UNetMidBlock3DCrossAttn(
in_channels=block_out_channels[-1],
temb_channels=time_embed_dim,
resnet_eps=norm_eps,
resnet_act_fn=act_fn,
output_scale_factor=mid_block_scale_factor,
cross_attention_dim=cross_attention_dim,
num_attention_heads=num_attention_heads[-1],
resnet_groups=norm_num_groups,
dual_cross_attention=False,
)
# count how many layers upsample the images
self.num_upsamplers = 0
# up
reversed_block_out_channels = list(reversed(block_out_channels))
reversed_num_attention_heads = list(reversed(num_attention_heads))
output_channel = reversed_block_out_channels[0]
for i, up_block_type in enumerate(up_block_types):
is_final_block = i == len(block_out_channels) - 1
prev_output_channel = output_channel
output_channel = reversed_block_out_channels[i]
input_channel = reversed_block_out_channels[min(i + 1, len(block_out_channels) - 1)]
# add upsample block for all BUT final layer
if not is_final_block:
add_upsample = True
self.num_upsamplers += 1
else:
add_upsample = False
up_block = get_up_block(
up_block_type,
num_layers=layers_per_block + 1,
in_channels=input_channel,
out_channels=output_channel,
prev_output_channel=prev_output_channel,
temb_channels=time_embed_dim,
add_upsample=add_upsample,
resnet_eps=norm_eps,
resnet_act_fn=act_fn,
resnet_groups=norm_num_groups,
cross_attention_dim=cross_attention_dim,
num_attention_heads=reversed_num_attention_heads[i],
dual_cross_attention=False,
)
self.up_blocks.append(up_block)
prev_output_channel = output_channel
# out
if norm_num_groups is not None:
self.conv_norm_out = nn.GroupNorm(
num_channels=block_out_channels[0], num_groups=norm_num_groups, eps=norm_eps
)
self.conv_act = nn.SiLU()
else:
self.conv_norm_out = None
self.conv_act = None
conv_out_padding = (conv_out_kernel - 1) // 2
self.conv_out = nn.Conv2d(
block_out_channels[0], out_channels, kernel_size=conv_out_kernel, padding=conv_out_padding
)
@property
# Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.attn_processors
def attn_processors(self) -> Dict[str, AttentionProcessor]:
r"""
Returns:
`dict` of attention processors: A dictionary containing all attention processors used in the model with
indexed by its weight name.
"""
# set recursively
processors = {}
def fn_recursive_add_processors(name: str, module: torch.nn.Module, processors: Dict[str, AttentionProcessor]):
if hasattr(module, "get_processor"):
processors[f"{name}.processor"] = module.get_processor(return_deprecated_lora=True)
for sub_name, child in module.named_children():
fn_recursive_add_processors(f"{name}.{sub_name}", child, processors)
return processors
for name, module in self.named_children():
fn_recursive_add_processors(name, module, processors)
return processors
# Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.set_attention_slice
def set_attention_slice(self, slice_size):
r"""
Enable sliced attention computation.
When this option is enabled, the attention module splits the input tensor in slices to compute attention in
several steps. This is useful for saving some memory in exchange for a small decrease in speed.
Args:
slice_size (`str` or `int` or `list(int)`, *optional*, defaults to `"auto"`):
When `"auto"`, input to the attention heads is halved, so attention is computed in two steps. If
`"max"`, maximum amount of memory is saved by running only one slice at a time. If a number is
provided, uses as many slices as `attention_head_dim // slice_size`. In this case, `attention_head_dim`
must be a multiple of `slice_size`.
"""
sliceable_head_dims = []
def fn_recursive_retrieve_sliceable_dims(module: torch.nn.Module):
if hasattr(module, "set_attention_slice"):
sliceable_head_dims.append(module.sliceable_head_dim)
for child in module.children():
fn_recursive_retrieve_sliceable_dims(child)
# retrieve number of attention layers
for module in self.children():
fn_recursive_retrieve_sliceable_dims(module)
num_sliceable_layers = len(sliceable_head_dims)
if slice_size == "auto":
# half the attention head size is usually a good trade-off between
# speed and memory
slice_size = [dim // 2 for dim in sliceable_head_dims]
elif slice_size == "max":
# make smallest slice possible
slice_size = num_sliceable_layers * [1]
slice_size = num_sliceable_layers * [slice_size] if not isinstance(slice_size, list) else slice_size
if len(slice_size) != len(sliceable_head_dims):
raise ValueError(
f"You have provided {len(slice_size)}, but {self.config} has {len(sliceable_head_dims)} different"
f" attention layers. Make sure to match `len(slice_size)` to be {len(sliceable_head_dims)}."
)
for i in range(len(slice_size)):
size = slice_size[i]
dim = sliceable_head_dims[i]
if size is not None and size > dim:
raise ValueError(f"size {size} has to be smaller or equal to {dim}.")
# Recursively walk through all the children.
# Any children which exposes the set_attention_slice method
# gets the message
def fn_recursive_set_attention_slice(module: torch.nn.Module, slice_size: List[int]):
if hasattr(module, "set_attention_slice"):
module.set_attention_slice(slice_size.pop())
for child in module.children():
fn_recursive_set_attention_slice(child, slice_size)
reversed_slice_size = list(reversed(slice_size))
for module in self.children():
fn_recursive_set_attention_slice(module, reversed_slice_size)
# Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.set_attn_processor
def set_attn_processor(self, processor: Union[AttentionProcessor, Dict[str, AttentionProcessor]]):
r"""
Sets the attention processor to use to compute attention.
Parameters:
processor (`dict` of `AttentionProcessor` or only `AttentionProcessor`):
The instantiated processor class or a dictionary of processor classes that will be set as the processor
for **all** `Attention` layers.
If `processor` is a dict, the key needs to define the path to the corresponding cross attention
processor. This is strongly recommended when setting trainable attention processors.
"""
count = len(self.attn_processors.keys())
if isinstance(processor, dict) and len(processor) != count:
raise ValueError(
f"A dict of processors was passed, but the number of processors {len(processor)} does not match the"
f" number of attention layers: {count}. Please make sure to pass {count} processor classes."
)
def fn_recursive_attn_processor(name: str, module: torch.nn.Module, processor):
if hasattr(module, "set_processor"):
if not isinstance(processor, dict):
module.set_processor(processor)
else:
module.set_processor(processor.pop(f"{name}.processor"))
for sub_name, child in module.named_children():
fn_recursive_attn_processor(f"{name}.{sub_name}", child, processor)
for name, module in self.named_children():
fn_recursive_attn_processor(name, module, processor)
def enable_forward_chunking(self, chunk_size=None, dim=0):
"""
Sets the attention processor to use [feed forward
chunking](https://huggingface.co/blog/reformer#2-chunked-feed-forward-layers).
Parameters:
chunk_size (`int`, *optional*):
The chunk size of the feed-forward layers. If not specified, will run feed-forward layer individually
over each tensor of dim=`dim`.
dim (`int`, *optional*, defaults to `0`):
The dimension over which the feed-forward computation should be chunked. Choose between dim=0 (batch)
or dim=1 (sequence length).
"""
if dim not in [0, 1]:
raise ValueError(f"Make sure to set `dim` to either 0 or 1, not {dim}")
# By default chunk size is 1
chunk_size = chunk_size or 1
def fn_recursive_feed_forward(module: torch.nn.Module, chunk_size: int, dim: int):
if hasattr(module, "set_chunk_feed_forward"):
module.set_chunk_feed_forward(chunk_size=chunk_size, dim=dim)
for child in module.children():
fn_recursive_feed_forward(child, chunk_size, dim)
for module in self.children():
fn_recursive_feed_forward(module, chunk_size, dim)
def disable_forward_chunking(self):
def fn_recursive_feed_forward(module: torch.nn.Module, chunk_size: int, dim: int):
if hasattr(module, "set_chunk_feed_forward"):
module.set_chunk_feed_forward(chunk_size=chunk_size, dim=dim)
for child in module.children():
fn_recursive_feed_forward(child, chunk_size, dim)
for module in self.children():
fn_recursive_feed_forward(module, None, 0)
# Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.set_default_attn_processor
def set_default_attn_processor(self):
"""
Disables custom attention processors and sets the default attention implementation.
"""
if all(proc.__class__ in ADDED_KV_ATTENTION_PROCESSORS for proc in self.attn_processors.values()):
processor = AttnAddedKVProcessor()
elif all(proc.__class__ in CROSS_ATTENTION_PROCESSORS for proc in self.attn_processors.values()):
processor = AttnProcessor()
else:
raise ValueError(
f"Cannot call `set_default_attn_processor` when attention processors are of type {next(iter(self.attn_processors.values()))}"
)
self.set_attn_processor(processor)
def _set_gradient_checkpointing(self, module, value=False):
if isinstance(module, (CrossAttnDownBlock3D, DownBlock3D, CrossAttnUpBlock3D, UpBlock3D)):
module.gradient_checkpointing = value
def forward(
self,
sample: torch.FloatTensor,
timestep: Union[torch.Tensor, float, int],
encoder_hidden_states: torch.Tensor,
class_labels: Optional[torch.Tensor] = None,
timestep_cond: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
down_block_additional_residuals: Optional[Tuple[torch.Tensor]] = None,
mid_block_additional_residual: Optional[torch.Tensor] = None,
return_dict: bool = True,
) -> Union[UNet3DConditionOutput, Tuple]:
r"""
The [`UNet3DConditionModel`] forward method.
Args:
sample (`torch.FloatTensor`):
The noisy input tensor with the following shape `(batch, num_frames, channel, height, width`.
timestep (`torch.FloatTensor` or `float` or `int`): The number of timesteps to denoise an input.
encoder_hidden_states (`torch.FloatTensor`):
The encoder hidden states with shape `(batch, sequence_length, feature_dim)`.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.unet_3d_condition.UNet3DConditionOutput`] instead of a plain
tuple.
cross_attention_kwargs (`dict`, *optional*):
A kwargs dictionary that if specified is passed along to the [`AttnProcessor`].
Returns:
[`~models.unet_3d_condition.UNet3DConditionOutput`] or `tuple`:
If `return_dict` is True, an [`~models.unet_3d_condition.UNet3DConditionOutput`] is returned, otherwise
a `tuple` is returned where the first element is the sample tensor.
"""
# By default samples have to be AT least a multiple of the overall upsampling factor.
# The overall upsampling factor is equal to 2 ** (# num of upsampling layears).
# However, the upsampling interpolation output size can be forced to fit any upsampling size
# on the fly if necessary.
default_overall_up_factor = 2**self.num_upsamplers
# upsample size should be forwarded when sample is not a multiple of `default_overall_up_factor`
forward_upsample_size = False
upsample_size = None
if any(s % default_overall_up_factor != 0 for s in sample.shape[-2:]):
logger.info("Forward upsample size to force interpolation output size.")
forward_upsample_size = True
# prepare attention_mask
if attention_mask is not None:
attention_mask = (1 - attention_mask.to(sample.dtype)) * -10000.0
attention_mask = attention_mask.unsqueeze(1)
# 1. time
timesteps = timestep
if not torch.is_tensor(timesteps):
# TODO: this requires sync between CPU and GPU. So try to pass timesteps as tensors if you can
# This would be a good case for the `match` statement (Python 3.10+)
is_mps = sample.device.type == "mps"
if isinstance(timestep, float):
dtype = torch.float32 if is_mps else torch.float64
else:
dtype = torch.int32 if is_mps else torch.int64
timesteps = torch.tensor([timesteps], dtype=dtype, device=sample.device)
elif len(timesteps.shape) == 0:
timesteps = timesteps[None].to(sample.device)
# broadcast to batch dimension in a way that's compatible with ONNX/Core ML
num_frames = sample.shape[2]
timesteps = timesteps.expand(sample.shape[0])
t_emb = self.time_proj(timesteps)
# timesteps does not contain any weights and will always return f32 tensors
# but time_embedding might actually be running in fp16. so we need to cast here.
# there might be better ways to encapsulate this.
t_emb = t_emb.to(dtype=self.dtype)
emb = self.time_embedding(t_emb, timestep_cond)
emb = emb.repeat_interleave(repeats=num_frames, dim=0)
encoder_hidden_states = encoder_hidden_states.repeat_interleave(repeats=num_frames, dim=0)
# 2. pre-process
sample = sample.permute(0, 2, 1, 3, 4).reshape((sample.shape[0] * num_frames, -1) + sample.shape[3:])
sample = self.conv_in(sample)
sample = self.transformer_in(
sample,
num_frames=num_frames,
cross_attention_kwargs=cross_attention_kwargs,
return_dict=False,
)[0]
# 3. down
down_block_res_samples = (sample,)
for downsample_block in self.down_blocks:
if hasattr(downsample_block, "has_cross_attention") and downsample_block.has_cross_attention:
sample, res_samples = downsample_block(
hidden_states=sample,
temb=emb,
encoder_hidden_states=encoder_hidden_states,
attention_mask=attention_mask,
num_frames=num_frames,
cross_attention_kwargs=cross_attention_kwargs,
)
else:
sample, res_samples = downsample_block(hidden_states=sample, temb=emb, num_frames=num_frames)
down_block_res_samples += res_samples
if down_block_additional_residuals is not None:
new_down_block_res_samples = ()
for down_block_res_sample, down_block_additional_residual in zip(
down_block_res_samples, down_block_additional_residuals
):
down_block_res_sample = down_block_res_sample + down_block_additional_residual
new_down_block_res_samples += (down_block_res_sample,)
down_block_res_samples = new_down_block_res_samples
# 4. mid
if self.mid_block is not None:
sample = self.mid_block(
sample,
emb,
encoder_hidden_states=encoder_hidden_states,
attention_mask=attention_mask,
num_frames=num_frames,
cross_attention_kwargs=cross_attention_kwargs,
)
if mid_block_additional_residual is not None:
sample = sample + mid_block_additional_residual
# 5. up
for i, upsample_block in enumerate(self.up_blocks):
is_final_block = i == len(self.up_blocks) - 1
res_samples = down_block_res_samples[-len(upsample_block.resnets) :]
down_block_res_samples = down_block_res_samples[: -len(upsample_block.resnets)]
# if we have not reached the final block and need to forward the
# upsample size, we do it here
if not is_final_block and forward_upsample_size:
upsample_size = down_block_res_samples[-1].shape[2:]
if hasattr(upsample_block, "has_cross_attention") and upsample_block.has_cross_attention:
sample = upsample_block(
hidden_states=sample,
temb=emb,
res_hidden_states_tuple=res_samples,
encoder_hidden_states=encoder_hidden_states,
upsample_size=upsample_size,
attention_mask=attention_mask,
num_frames=num_frames,
cross_attention_kwargs=cross_attention_kwargs,
)
else:
sample = upsample_block(
hidden_states=sample,
temb=emb,
res_hidden_states_tuple=res_samples,
upsample_size=upsample_size,
num_frames=num_frames,
)
# 6. post-process
if self.conv_norm_out:
sample = self.conv_norm_out(sample)
sample = self.conv_act(sample)
sample = self.conv_out(sample)
# reshape to (batch, channel, framerate, width, height)
sample = sample[None, :].reshape((-1, num_frames) + sample.shape[1:]).permute(0, 2, 1, 3, 4)
if not return_dict:
return (sample,)
return UNet3DConditionOutput(sample=sample)
| diffusers-main | src/diffusers/models/unet_3d_condition.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Optional
import torch
import torch.nn.functional as F
from torch import nn
from ..loaders import PatchedLoraProjection, text_encoder_attn_modules, text_encoder_mlp_modules
from ..utils import logging
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
def adjust_lora_scale_text_encoder(text_encoder, lora_scale: float = 1.0):
for _, attn_module in text_encoder_attn_modules(text_encoder):
if isinstance(attn_module.q_proj, PatchedLoraProjection):
attn_module.q_proj.lora_scale = lora_scale
attn_module.k_proj.lora_scale = lora_scale
attn_module.v_proj.lora_scale = lora_scale
attn_module.out_proj.lora_scale = lora_scale
for _, mlp_module in text_encoder_mlp_modules(text_encoder):
if isinstance(mlp_module.fc1, PatchedLoraProjection):
mlp_module.fc1.lora_scale = lora_scale
mlp_module.fc2.lora_scale = lora_scale
class LoRALinearLayer(nn.Module):
def __init__(self, in_features, out_features, rank=4, network_alpha=None, device=None, dtype=None):
super().__init__()
self.down = nn.Linear(in_features, rank, bias=False, device=device, dtype=dtype)
self.up = nn.Linear(rank, out_features, bias=False, device=device, dtype=dtype)
# This value has the same meaning as the `--network_alpha` option in the kohya-ss trainer script.
# See https://github.com/darkstorm2150/sd-scripts/blob/main/docs/train_network_README-en.md#execute-learning
self.network_alpha = network_alpha
self.rank = rank
self.out_features = out_features
self.in_features = in_features
nn.init.normal_(self.down.weight, std=1 / rank)
nn.init.zeros_(self.up.weight)
def forward(self, hidden_states):
orig_dtype = hidden_states.dtype
dtype = self.down.weight.dtype
down_hidden_states = self.down(hidden_states.to(dtype))
up_hidden_states = self.up(down_hidden_states)
if self.network_alpha is not None:
up_hidden_states *= self.network_alpha / self.rank
return up_hidden_states.to(orig_dtype)
class LoRAConv2dLayer(nn.Module):
def __init__(
self, in_features, out_features, rank=4, kernel_size=(1, 1), stride=(1, 1), padding=0, network_alpha=None
):
super().__init__()
self.down = nn.Conv2d(in_features, rank, kernel_size=kernel_size, stride=stride, padding=padding, bias=False)
# according to the official kohya_ss trainer kernel_size are always fixed for the up layer
# # see: https://github.com/bmaltais/kohya_ss/blob/2accb1305979ba62f5077a23aabac23b4c37e935/networks/lora_diffusers.py#L129
self.up = nn.Conv2d(rank, out_features, kernel_size=(1, 1), stride=(1, 1), bias=False)
# This value has the same meaning as the `--network_alpha` option in the kohya-ss trainer script.
# See https://github.com/darkstorm2150/sd-scripts/blob/main/docs/train_network_README-en.md#execute-learning
self.network_alpha = network_alpha
self.rank = rank
nn.init.normal_(self.down.weight, std=1 / rank)
nn.init.zeros_(self.up.weight)
def forward(self, hidden_states):
orig_dtype = hidden_states.dtype
dtype = self.down.weight.dtype
down_hidden_states = self.down(hidden_states.to(dtype))
up_hidden_states = self.up(down_hidden_states)
if self.network_alpha is not None:
up_hidden_states *= self.network_alpha / self.rank
return up_hidden_states.to(orig_dtype)
class LoRACompatibleConv(nn.Conv2d):
"""
A convolutional layer that can be used with LoRA.
"""
def __init__(self, *args, lora_layer: Optional[LoRAConv2dLayer] = None, **kwargs):
super().__init__(*args, **kwargs)
self.lora_layer = lora_layer
def set_lora_layer(self, lora_layer: Optional[LoRAConv2dLayer]):
self.lora_layer = lora_layer
def _fuse_lora(self, lora_scale=1.0):
if self.lora_layer is None:
return
dtype, device = self.weight.data.dtype, self.weight.data.device
w_orig = self.weight.data.float()
w_up = self.lora_layer.up.weight.data.float()
w_down = self.lora_layer.down.weight.data.float()
if self.lora_layer.network_alpha is not None:
w_up = w_up * self.lora_layer.network_alpha / self.lora_layer.rank
fusion = torch.mm(w_up.flatten(start_dim=1), w_down.flatten(start_dim=1))
fusion = fusion.reshape((w_orig.shape))
fused_weight = w_orig + (lora_scale * fusion)
self.weight.data = fused_weight.to(device=device, dtype=dtype)
# we can drop the lora layer now
self.lora_layer = None
# offload the up and down matrices to CPU to not blow the memory
self.w_up = w_up.cpu()
self.w_down = w_down.cpu()
self._lora_scale = lora_scale
def _unfuse_lora(self):
if not (getattr(self, "w_up", None) is not None and getattr(self, "w_down", None) is not None):
return
fused_weight = self.weight.data
dtype, device = fused_weight.data.dtype, fused_weight.data.device
self.w_up = self.w_up.to(device=device).float()
self.w_down = self.w_down.to(device).float()
fusion = torch.mm(self.w_up.flatten(start_dim=1), self.w_down.flatten(start_dim=1))
fusion = fusion.reshape((fused_weight.shape))
unfused_weight = fused_weight.float() - (self._lora_scale * fusion)
self.weight.data = unfused_weight.to(device=device, dtype=dtype)
self.w_up = None
self.w_down = None
def forward(self, hidden_states, scale: float = 1.0):
if self.lora_layer is None:
# make sure to the functional Conv2D function as otherwise torch.compile's graph will break
# see: https://github.com/huggingface/diffusers/pull/4315
return F.conv2d(
hidden_states, self.weight, self.bias, self.stride, self.padding, self.dilation, self.groups
)
else:
return super().forward(hidden_states) + (scale * self.lora_layer(hidden_states))
class LoRACompatibleLinear(nn.Linear):
"""
A Linear layer that can be used with LoRA.
"""
def __init__(self, *args, lora_layer: Optional[LoRALinearLayer] = None, **kwargs):
super().__init__(*args, **kwargs)
self.lora_layer = lora_layer
def set_lora_layer(self, lora_layer: Optional[LoRALinearLayer]):
self.lora_layer = lora_layer
def _fuse_lora(self, lora_scale=1.0):
if self.lora_layer is None:
return
dtype, device = self.weight.data.dtype, self.weight.data.device
w_orig = self.weight.data.float()
w_up = self.lora_layer.up.weight.data.float()
w_down = self.lora_layer.down.weight.data.float()
if self.lora_layer.network_alpha is not None:
w_up = w_up * self.lora_layer.network_alpha / self.lora_layer.rank
fused_weight = w_orig + (lora_scale * torch.bmm(w_up[None, :], w_down[None, :])[0])
self.weight.data = fused_weight.to(device=device, dtype=dtype)
# we can drop the lora layer now
self.lora_layer = None
# offload the up and down matrices to CPU to not blow the memory
self.w_up = w_up.cpu()
self.w_down = w_down.cpu()
self._lora_scale = lora_scale
def _unfuse_lora(self):
if not (getattr(self, "w_up", None) is not None and getattr(self, "w_down", None) is not None):
return
fused_weight = self.weight.data
dtype, device = fused_weight.dtype, fused_weight.device
w_up = self.w_up.to(device=device).float()
w_down = self.w_down.to(device).float()
unfused_weight = fused_weight.float() - (self._lora_scale * torch.bmm(w_up[None, :], w_down[None, :])[0])
self.weight.data = unfused_weight.to(device=device, dtype=dtype)
self.w_up = None
self.w_down = None
def forward(self, hidden_states, scale: float = 1.0):
if self.lora_layer is None:
out = super().forward(hidden_states)
return out
else:
out = super().forward(hidden_states) + (scale * self.lora_layer(hidden_states))
return out
| diffusers-main | src/diffusers/models/lora.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Any, Dict, Optional
import torch
import torch.nn.functional as F
from torch import nn
from ..configuration_utils import ConfigMixin, register_to_config
from ..models.embeddings import ImagePositionalEmbeddings
from ..utils import BaseOutput, deprecate
from .attention import BasicTransformerBlock
from .embeddings import PatchEmbed
from .lora import LoRACompatibleConv, LoRACompatibleLinear
from .modeling_utils import ModelMixin
@dataclass
class Transformer2DModelOutput(BaseOutput):
"""
The output of [`Transformer2DModel`].
Args:
sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` or `(batch size, num_vector_embeds - 1, num_latent_pixels)` if [`Transformer2DModel`] is discrete):
The hidden states output conditioned on the `encoder_hidden_states` input. If discrete, returns probability
distributions for the unnoised latent pixels.
"""
sample: torch.FloatTensor
class Transformer2DModel(ModelMixin, ConfigMixin):
"""
A 2D Transformer model for image-like data.
Parameters:
num_attention_heads (`int`, *optional*, defaults to 16): The number of heads to use for multi-head attention.
attention_head_dim (`int`, *optional*, defaults to 88): The number of channels in each head.
in_channels (`int`, *optional*):
The number of channels in the input and output (specify if the input is **continuous**).
num_layers (`int`, *optional*, defaults to 1): The number of layers of Transformer blocks to use.
dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
cross_attention_dim (`int`, *optional*): The number of `encoder_hidden_states` dimensions to use.
sample_size (`int`, *optional*): The width of the latent images (specify if the input is **discrete**).
This is fixed during training since it is used to learn a number of position embeddings.
num_vector_embeds (`int`, *optional*):
The number of classes of the vector embeddings of the latent pixels (specify if the input is **discrete**).
Includes the class for the masked latent pixel.
activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to use in feed-forward.
num_embeds_ada_norm ( `int`, *optional*):
The number of diffusion steps used during training. Pass if at least one of the norm_layers is
`AdaLayerNorm`. This is fixed during training since it is used to learn a number of embeddings that are
added to the hidden states.
During inference, you can denoise for up to but not more steps than `num_embeds_ada_norm`.
attention_bias (`bool`, *optional*):
Configure if the `TransformerBlocks` attention should contain a bias parameter.
"""
@register_to_config
def __init__(
self,
num_attention_heads: int = 16,
attention_head_dim: int = 88,
in_channels: Optional[int] = None,
out_channels: Optional[int] = None,
num_layers: int = 1,
dropout: float = 0.0,
norm_num_groups: int = 32,
cross_attention_dim: Optional[int] = None,
attention_bias: bool = False,
sample_size: Optional[int] = None,
num_vector_embeds: Optional[int] = None,
patch_size: Optional[int] = None,
activation_fn: str = "geglu",
num_embeds_ada_norm: Optional[int] = None,
use_linear_projection: bool = False,
only_cross_attention: bool = False,
double_self_attention: bool = False,
upcast_attention: bool = False,
norm_type: str = "layer_norm",
norm_elementwise_affine: bool = True,
attention_type: str = "default",
):
super().__init__()
self.use_linear_projection = use_linear_projection
self.num_attention_heads = num_attention_heads
self.attention_head_dim = attention_head_dim
inner_dim = num_attention_heads * attention_head_dim
# 1. Transformer2DModel can process both standard continuous images of shape `(batch_size, num_channels, width, height)` as well as quantized image embeddings of shape `(batch_size, num_image_vectors)`
# Define whether input is continuous or discrete depending on configuration
self.is_input_continuous = (in_channels is not None) and (patch_size is None)
self.is_input_vectorized = num_vector_embeds is not None
self.is_input_patches = in_channels is not None and patch_size is not None
if norm_type == "layer_norm" and num_embeds_ada_norm is not None:
deprecation_message = (
f"The configuration file of this model: {self.__class__} is outdated. `norm_type` is either not set or"
" incorrectly set to `'layer_norm'`.Make sure to set `norm_type` to `'ada_norm'` in the config."
" Please make sure to update the config accordingly as leaving `norm_type` might led to incorrect"
" results in future versions. If you have downloaded this checkpoint from the Hugging Face Hub, it"
" would be very nice if you could open a Pull request for the `transformer/config.json` file"
)
deprecate("norm_type!=num_embeds_ada_norm", "1.0.0", deprecation_message, standard_warn=False)
norm_type = "ada_norm"
if self.is_input_continuous and self.is_input_vectorized:
raise ValueError(
f"Cannot define both `in_channels`: {in_channels} and `num_vector_embeds`: {num_vector_embeds}. Make"
" sure that either `in_channels` or `num_vector_embeds` is None."
)
elif self.is_input_vectorized and self.is_input_patches:
raise ValueError(
f"Cannot define both `num_vector_embeds`: {num_vector_embeds} and `patch_size`: {patch_size}. Make"
" sure that either `num_vector_embeds` or `num_patches` is None."
)
elif not self.is_input_continuous and not self.is_input_vectorized and not self.is_input_patches:
raise ValueError(
f"Has to define `in_channels`: {in_channels}, `num_vector_embeds`: {num_vector_embeds}, or patch_size:"
f" {patch_size}. Make sure that `in_channels`, `num_vector_embeds` or `num_patches` is not None."
)
# 2. Define input layers
if self.is_input_continuous:
self.in_channels = in_channels
self.norm = torch.nn.GroupNorm(num_groups=norm_num_groups, num_channels=in_channels, eps=1e-6, affine=True)
if use_linear_projection:
self.proj_in = LoRACompatibleLinear(in_channels, inner_dim)
else:
self.proj_in = LoRACompatibleConv(in_channels, inner_dim, kernel_size=1, stride=1, padding=0)
elif self.is_input_vectorized:
assert sample_size is not None, "Transformer2DModel over discrete input must provide sample_size"
assert num_vector_embeds is not None, "Transformer2DModel over discrete input must provide num_embed"
self.height = sample_size
self.width = sample_size
self.num_vector_embeds = num_vector_embeds
self.num_latent_pixels = self.height * self.width
self.latent_image_embedding = ImagePositionalEmbeddings(
num_embed=num_vector_embeds, embed_dim=inner_dim, height=self.height, width=self.width
)
elif self.is_input_patches:
assert sample_size is not None, "Transformer2DModel over patched input must provide sample_size"
self.height = sample_size
self.width = sample_size
self.patch_size = patch_size
self.pos_embed = PatchEmbed(
height=sample_size,
width=sample_size,
patch_size=patch_size,
in_channels=in_channels,
embed_dim=inner_dim,
)
# 3. Define transformers blocks
self.transformer_blocks = nn.ModuleList(
[
BasicTransformerBlock(
inner_dim,
num_attention_heads,
attention_head_dim,
dropout=dropout,
cross_attention_dim=cross_attention_dim,
activation_fn=activation_fn,
num_embeds_ada_norm=num_embeds_ada_norm,
attention_bias=attention_bias,
only_cross_attention=only_cross_attention,
double_self_attention=double_self_attention,
upcast_attention=upcast_attention,
norm_type=norm_type,
norm_elementwise_affine=norm_elementwise_affine,
attention_type=attention_type,
)
for d in range(num_layers)
]
)
# 4. Define output layers
self.out_channels = in_channels if out_channels is None else out_channels
if self.is_input_continuous:
# TODO: should use out_channels for continuous projections
if use_linear_projection:
self.proj_out = LoRACompatibleLinear(inner_dim, in_channels)
else:
self.proj_out = LoRACompatibleConv(inner_dim, in_channels, kernel_size=1, stride=1, padding=0)
elif self.is_input_vectorized:
self.norm_out = nn.LayerNorm(inner_dim)
self.out = nn.Linear(inner_dim, self.num_vector_embeds - 1)
elif self.is_input_patches:
self.norm_out = nn.LayerNorm(inner_dim, elementwise_affine=False, eps=1e-6)
self.proj_out_1 = nn.Linear(inner_dim, 2 * inner_dim)
self.proj_out_2 = nn.Linear(inner_dim, patch_size * patch_size * self.out_channels)
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor] = None,
timestep: Optional[torch.LongTensor] = None,
class_labels: Optional[torch.LongTensor] = None,
cross_attention_kwargs: Dict[str, Any] = None,
attention_mask: Optional[torch.Tensor] = None,
encoder_attention_mask: Optional[torch.Tensor] = None,
return_dict: bool = True,
):
"""
The [`Transformer2DModel`] forward method.
Args:
hidden_states (`torch.LongTensor` of shape `(batch size, num latent pixels)` if discrete, `torch.FloatTensor` of shape `(batch size, channel, height, width)` if continuous):
Input `hidden_states`.
encoder_hidden_states ( `torch.FloatTensor` of shape `(batch size, sequence len, embed dims)`, *optional*):
Conditional embeddings for cross attention layer. If not given, cross-attention defaults to
self-attention.
timestep ( `torch.LongTensor`, *optional*):
Used to indicate denoising step. Optional timestep to be applied as an embedding in `AdaLayerNorm`.
class_labels ( `torch.LongTensor` of shape `(batch size, num classes)`, *optional*):
Used to indicate class labels conditioning. Optional class labels to be applied as an embedding in
`AdaLayerZeroNorm`.
encoder_attention_mask ( `torch.Tensor`, *optional*):
Cross-attention mask applied to `encoder_hidden_states`. Two formats supported:
* Mask `(batch, sequence_length)` True = keep, False = discard.
* Bias `(batch, 1, sequence_length)` 0 = keep, -10000 = discard.
If `ndim == 2`: will be interpreted as a mask, then converted into a bias consistent with the format
above. This bias will be added to the cross-attention scores.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.unet_2d_condition.UNet2DConditionOutput`] instead of a plain
tuple.
Returns:
If `return_dict` is True, an [`~models.transformer_2d.Transformer2DModelOutput`] is returned, otherwise a
`tuple` where the first element is the sample tensor.
"""
# ensure attention_mask is a bias, and give it a singleton query_tokens dimension.
# we may have done this conversion already, e.g. if we came here via UNet2DConditionModel#forward.
# we can tell by counting dims; if ndim == 2: it's a mask rather than a bias.
# expects mask of shape:
# [batch, key_tokens]
# adds singleton query_tokens dimension:
# [batch, 1, key_tokens]
# this helps to broadcast it as a bias over attention scores, which will be in one of the following shapes:
# [batch, heads, query_tokens, key_tokens] (e.g. torch sdp attn)
# [batch * heads, query_tokens, key_tokens] (e.g. xformers or classic attn)
if attention_mask is not None and attention_mask.ndim == 2:
# assume that mask is expressed as:
# (1 = keep, 0 = discard)
# convert mask into a bias that can be added to attention scores:
# (keep = +0, discard = -10000.0)
attention_mask = (1 - attention_mask.to(hidden_states.dtype)) * -10000.0
attention_mask = attention_mask.unsqueeze(1)
# convert encoder_attention_mask to a bias the same way we do for attention_mask
if encoder_attention_mask is not None and encoder_attention_mask.ndim == 2:
encoder_attention_mask = (1 - encoder_attention_mask.to(hidden_states.dtype)) * -10000.0
encoder_attention_mask = encoder_attention_mask.unsqueeze(1)
# Retrieve lora scale.
lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0
# 1. Input
if self.is_input_continuous:
batch, _, height, width = hidden_states.shape
residual = hidden_states
hidden_states = self.norm(hidden_states)
if not self.use_linear_projection:
hidden_states = self.proj_in(hidden_states, scale=lora_scale)
inner_dim = hidden_states.shape[1]
hidden_states = hidden_states.permute(0, 2, 3, 1).reshape(batch, height * width, inner_dim)
else:
inner_dim = hidden_states.shape[1]
hidden_states = hidden_states.permute(0, 2, 3, 1).reshape(batch, height * width, inner_dim)
hidden_states = self.proj_in(hidden_states, scale=lora_scale)
elif self.is_input_vectorized:
hidden_states = self.latent_image_embedding(hidden_states)
elif self.is_input_patches:
hidden_states = self.pos_embed(hidden_states)
# 2. Blocks
for block in self.transformer_blocks:
if self.training and self.gradient_checkpointing:
hidden_states = torch.utils.checkpoint.checkpoint(
block,
hidden_states,
attention_mask,
encoder_hidden_states,
encoder_attention_mask,
timestep,
cross_attention_kwargs,
class_labels,
use_reentrant=False,
)
else:
hidden_states = block(
hidden_states,
attention_mask=attention_mask,
encoder_hidden_states=encoder_hidden_states,
encoder_attention_mask=encoder_attention_mask,
timestep=timestep,
cross_attention_kwargs=cross_attention_kwargs,
class_labels=class_labels,
)
# 3. Output
if self.is_input_continuous:
if not self.use_linear_projection:
hidden_states = hidden_states.reshape(batch, height, width, inner_dim).permute(0, 3, 1, 2).contiguous()
hidden_states = self.proj_out(hidden_states, scale=lora_scale)
else:
hidden_states = self.proj_out(hidden_states, scale=lora_scale)
hidden_states = hidden_states.reshape(batch, height, width, inner_dim).permute(0, 3, 1, 2).contiguous()
output = hidden_states + residual
elif self.is_input_vectorized:
hidden_states = self.norm_out(hidden_states)
logits = self.out(hidden_states)
# (batch, self.num_vector_embeds - 1, self.num_latent_pixels)
logits = logits.permute(0, 2, 1)
# log(p(x_0))
output = F.log_softmax(logits.double(), dim=1).float()
elif self.is_input_patches:
# TODO: cleanup!
conditioning = self.transformer_blocks[0].norm1.emb(
timestep, class_labels, hidden_dtype=hidden_states.dtype
)
shift, scale = self.proj_out_1(F.silu(conditioning)).chunk(2, dim=1)
hidden_states = self.norm_out(hidden_states) * (1 + scale[:, None]) + shift[:, None]
hidden_states = self.proj_out_2(hidden_states)
# unpatchify
height = width = int(hidden_states.shape[1] ** 0.5)
hidden_states = hidden_states.reshape(
shape=(-1, height, width, self.patch_size, self.patch_size, self.out_channels)
)
hidden_states = torch.einsum("nhwpqc->nchpwq", hidden_states)
output = hidden_states.reshape(
shape=(-1, self.out_channels, height * self.patch_size, width * self.patch_size)
)
if not return_dict:
return (output,)
return Transformer2DModelOutput(sample=output)
| diffusers-main | src/diffusers/models/transformer_2d.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# JAX implementation of VQGAN from taming-transformers https://github.com/CompVis/taming-transformers
import math
from functools import partial
from typing import Tuple
import flax
import flax.linen as nn
import jax
import jax.numpy as jnp
from flax.core.frozen_dict import FrozenDict
from ..configuration_utils import ConfigMixin, flax_register_to_config
from ..utils import BaseOutput
from .modeling_flax_utils import FlaxModelMixin
@flax.struct.dataclass
class FlaxDecoderOutput(BaseOutput):
"""
Output of decoding method.
Args:
sample (`jnp.ndarray` of shape `(batch_size, num_channels, height, width)`):
The decoded output sample from the last layer of the model.
dtype (`jnp.dtype`, *optional*, defaults to `jnp.float32`):
The `dtype` of the parameters.
"""
sample: jnp.ndarray
@flax.struct.dataclass
class FlaxAutoencoderKLOutput(BaseOutput):
"""
Output of AutoencoderKL encoding method.
Args:
latent_dist (`FlaxDiagonalGaussianDistribution`):
Encoded outputs of `Encoder` represented as the mean and logvar of `FlaxDiagonalGaussianDistribution`.
`FlaxDiagonalGaussianDistribution` allows for sampling latents from the distribution.
"""
latent_dist: "FlaxDiagonalGaussianDistribution"
class FlaxUpsample2D(nn.Module):
"""
Flax implementation of 2D Upsample layer
Args:
in_channels (`int`):
Input channels
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
dtype: jnp.dtype = jnp.float32
def setup(self):
self.conv = nn.Conv(
self.in_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
def __call__(self, hidden_states):
batch, height, width, channels = hidden_states.shape
hidden_states = jax.image.resize(
hidden_states,
shape=(batch, height * 2, width * 2, channels),
method="nearest",
)
hidden_states = self.conv(hidden_states)
return hidden_states
class FlaxDownsample2D(nn.Module):
"""
Flax implementation of 2D Downsample layer
Args:
in_channels (`int`):
Input channels
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
dtype: jnp.dtype = jnp.float32
def setup(self):
self.conv = nn.Conv(
self.in_channels,
kernel_size=(3, 3),
strides=(2, 2),
padding="VALID",
dtype=self.dtype,
)
def __call__(self, hidden_states):
pad = ((0, 0), (0, 1), (0, 1), (0, 0)) # pad height and width dim
hidden_states = jnp.pad(hidden_states, pad_width=pad)
hidden_states = self.conv(hidden_states)
return hidden_states
class FlaxResnetBlock2D(nn.Module):
"""
Flax implementation of 2D Resnet Block.
Args:
in_channels (`int`):
Input channels
out_channels (`int`):
Output channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
groups (:obj:`int`, *optional*, defaults to `32`):
The number of groups to use for group norm.
use_nin_shortcut (:obj:`bool`, *optional*, defaults to `None`):
Whether to use `nin_shortcut`. This activates a new layer inside ResNet block
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
out_channels: int = None
dropout: float = 0.0
groups: int = 32
use_nin_shortcut: bool = None
dtype: jnp.dtype = jnp.float32
def setup(self):
out_channels = self.in_channels if self.out_channels is None else self.out_channels
self.norm1 = nn.GroupNorm(num_groups=self.groups, epsilon=1e-6)
self.conv1 = nn.Conv(
out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
self.norm2 = nn.GroupNorm(num_groups=self.groups, epsilon=1e-6)
self.dropout_layer = nn.Dropout(self.dropout)
self.conv2 = nn.Conv(
out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
use_nin_shortcut = self.in_channels != out_channels if self.use_nin_shortcut is None else self.use_nin_shortcut
self.conv_shortcut = None
if use_nin_shortcut:
self.conv_shortcut = nn.Conv(
out_channels,
kernel_size=(1, 1),
strides=(1, 1),
padding="VALID",
dtype=self.dtype,
)
def __call__(self, hidden_states, deterministic=True):
residual = hidden_states
hidden_states = self.norm1(hidden_states)
hidden_states = nn.swish(hidden_states)
hidden_states = self.conv1(hidden_states)
hidden_states = self.norm2(hidden_states)
hidden_states = nn.swish(hidden_states)
hidden_states = self.dropout_layer(hidden_states, deterministic)
hidden_states = self.conv2(hidden_states)
if self.conv_shortcut is not None:
residual = self.conv_shortcut(residual)
return hidden_states + residual
class FlaxAttentionBlock(nn.Module):
r"""
Flax Convolutional based multi-head attention block for diffusion-based VAE.
Parameters:
channels (:obj:`int`):
Input channels
num_head_channels (:obj:`int`, *optional*, defaults to `None`):
Number of attention heads
num_groups (:obj:`int`, *optional*, defaults to `32`):
The number of groups to use for group norm
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
channels: int
num_head_channels: int = None
num_groups: int = 32
dtype: jnp.dtype = jnp.float32
def setup(self):
self.num_heads = self.channels // self.num_head_channels if self.num_head_channels is not None else 1
dense = partial(nn.Dense, self.channels, dtype=self.dtype)
self.group_norm = nn.GroupNorm(num_groups=self.num_groups, epsilon=1e-6)
self.query, self.key, self.value = dense(), dense(), dense()
self.proj_attn = dense()
def transpose_for_scores(self, projection):
new_projection_shape = projection.shape[:-1] + (self.num_heads, -1)
# move heads to 2nd position (B, T, H * D) -> (B, T, H, D)
new_projection = projection.reshape(new_projection_shape)
# (B, T, H, D) -> (B, H, T, D)
new_projection = jnp.transpose(new_projection, (0, 2, 1, 3))
return new_projection
def __call__(self, hidden_states):
residual = hidden_states
batch, height, width, channels = hidden_states.shape
hidden_states = self.group_norm(hidden_states)
hidden_states = hidden_states.reshape((batch, height * width, channels))
query = self.query(hidden_states)
key = self.key(hidden_states)
value = self.value(hidden_states)
# transpose
query = self.transpose_for_scores(query)
key = self.transpose_for_scores(key)
value = self.transpose_for_scores(value)
# compute attentions
scale = 1 / math.sqrt(math.sqrt(self.channels / self.num_heads))
attn_weights = jnp.einsum("...qc,...kc->...qk", query * scale, key * scale)
attn_weights = nn.softmax(attn_weights, axis=-1)
# attend to values
hidden_states = jnp.einsum("...kc,...qk->...qc", value, attn_weights)
hidden_states = jnp.transpose(hidden_states, (0, 2, 1, 3))
new_hidden_states_shape = hidden_states.shape[:-2] + (self.channels,)
hidden_states = hidden_states.reshape(new_hidden_states_shape)
hidden_states = self.proj_attn(hidden_states)
hidden_states = hidden_states.reshape((batch, height, width, channels))
hidden_states = hidden_states + residual
return hidden_states
class FlaxDownEncoderBlock2D(nn.Module):
r"""
Flax Resnet blocks-based Encoder block for diffusion-based VAE.
Parameters:
in_channels (:obj:`int`):
Input channels
out_channels (:obj:`int`):
Output channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of Resnet layer block
resnet_groups (:obj:`int`, *optional*, defaults to `32`):
The number of groups to use for the Resnet block group norm
add_downsample (:obj:`bool`, *optional*, defaults to `True`):
Whether to add downsample layer
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
out_channels: int
dropout: float = 0.0
num_layers: int = 1
resnet_groups: int = 32
add_downsample: bool = True
dtype: jnp.dtype = jnp.float32
def setup(self):
resnets = []
for i in range(self.num_layers):
in_channels = self.in_channels if i == 0 else self.out_channels
res_block = FlaxResnetBlock2D(
in_channels=in_channels,
out_channels=self.out_channels,
dropout=self.dropout,
groups=self.resnet_groups,
dtype=self.dtype,
)
resnets.append(res_block)
self.resnets = resnets
if self.add_downsample:
self.downsamplers_0 = FlaxDownsample2D(self.out_channels, dtype=self.dtype)
def __call__(self, hidden_states, deterministic=True):
for resnet in self.resnets:
hidden_states = resnet(hidden_states, deterministic=deterministic)
if self.add_downsample:
hidden_states = self.downsamplers_0(hidden_states)
return hidden_states
class FlaxUpDecoderBlock2D(nn.Module):
r"""
Flax Resnet blocks-based Decoder block for diffusion-based VAE.
Parameters:
in_channels (:obj:`int`):
Input channels
out_channels (:obj:`int`):
Output channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of Resnet layer block
resnet_groups (:obj:`int`, *optional*, defaults to `32`):
The number of groups to use for the Resnet block group norm
add_upsample (:obj:`bool`, *optional*, defaults to `True`):
Whether to add upsample layer
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
out_channels: int
dropout: float = 0.0
num_layers: int = 1
resnet_groups: int = 32
add_upsample: bool = True
dtype: jnp.dtype = jnp.float32
def setup(self):
resnets = []
for i in range(self.num_layers):
in_channels = self.in_channels if i == 0 else self.out_channels
res_block = FlaxResnetBlock2D(
in_channels=in_channels,
out_channels=self.out_channels,
dropout=self.dropout,
groups=self.resnet_groups,
dtype=self.dtype,
)
resnets.append(res_block)
self.resnets = resnets
if self.add_upsample:
self.upsamplers_0 = FlaxUpsample2D(self.out_channels, dtype=self.dtype)
def __call__(self, hidden_states, deterministic=True):
for resnet in self.resnets:
hidden_states = resnet(hidden_states, deterministic=deterministic)
if self.add_upsample:
hidden_states = self.upsamplers_0(hidden_states)
return hidden_states
class FlaxUNetMidBlock2D(nn.Module):
r"""
Flax Unet Mid-Block module.
Parameters:
in_channels (:obj:`int`):
Input channels
dropout (:obj:`float`, *optional*, defaults to 0.0):
Dropout rate
num_layers (:obj:`int`, *optional*, defaults to 1):
Number of Resnet layer block
resnet_groups (:obj:`int`, *optional*, defaults to `32`):
The number of groups to use for the Resnet and Attention block group norm
num_attention_heads (:obj:`int`, *optional*, defaults to `1`):
Number of attention heads for each attention block
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int
dropout: float = 0.0
num_layers: int = 1
resnet_groups: int = 32
num_attention_heads: int = 1
dtype: jnp.dtype = jnp.float32
def setup(self):
resnet_groups = self.resnet_groups if self.resnet_groups is not None else min(self.in_channels // 4, 32)
# there is always at least one resnet
resnets = [
FlaxResnetBlock2D(
in_channels=self.in_channels,
out_channels=self.in_channels,
dropout=self.dropout,
groups=resnet_groups,
dtype=self.dtype,
)
]
attentions = []
for _ in range(self.num_layers):
attn_block = FlaxAttentionBlock(
channels=self.in_channels,
num_head_channels=self.num_attention_heads,
num_groups=resnet_groups,
dtype=self.dtype,
)
attentions.append(attn_block)
res_block = FlaxResnetBlock2D(
in_channels=self.in_channels,
out_channels=self.in_channels,
dropout=self.dropout,
groups=resnet_groups,
dtype=self.dtype,
)
resnets.append(res_block)
self.resnets = resnets
self.attentions = attentions
def __call__(self, hidden_states, deterministic=True):
hidden_states = self.resnets[0](hidden_states, deterministic=deterministic)
for attn, resnet in zip(self.attentions, self.resnets[1:]):
hidden_states = attn(hidden_states)
hidden_states = resnet(hidden_states, deterministic=deterministic)
return hidden_states
class FlaxEncoder(nn.Module):
r"""
Flax Implementation of VAE Encoder.
This model is a Flax Linen [flax.linen.Module](https://flax.readthedocs.io/en/latest/flax.linen.html#module)
subclass. Use it as a regular Flax linen Module and refer to the Flax documentation for all matter related to
general usage and behavior.
Finally, this model supports inherent JAX features such as:
- [Just-In-Time (JIT) compilation](https://jax.readthedocs.io/en/latest/jax.html#just-in-time-compilation-jit)
- [Automatic Differentiation](https://jax.readthedocs.io/en/latest/jax.html#automatic-differentiation)
- [Vectorization](https://jax.readthedocs.io/en/latest/jax.html#vectorization-vmap)
- [Parallelization](https://jax.readthedocs.io/en/latest/jax.html#parallelization-pmap)
Parameters:
in_channels (:obj:`int`, *optional*, defaults to 3):
Input channels
out_channels (:obj:`int`, *optional*, defaults to 3):
Output channels
down_block_types (:obj:`Tuple[str]`, *optional*, defaults to `(DownEncoderBlock2D)`):
DownEncoder block type
block_out_channels (:obj:`Tuple[str]`, *optional*, defaults to `(64,)`):
Tuple containing the number of output channels for each block
layers_per_block (:obj:`int`, *optional*, defaults to `2`):
Number of Resnet layer for each block
norm_num_groups (:obj:`int`, *optional*, defaults to `32`):
norm num group
act_fn (:obj:`str`, *optional*, defaults to `silu`):
Activation function
double_z (:obj:`bool`, *optional*, defaults to `False`):
Whether to double the last output channels
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
Parameters `dtype`
"""
in_channels: int = 3
out_channels: int = 3
down_block_types: Tuple[str] = ("DownEncoderBlock2D",)
block_out_channels: Tuple[int] = (64,)
layers_per_block: int = 2
norm_num_groups: int = 32
act_fn: str = "silu"
double_z: bool = False
dtype: jnp.dtype = jnp.float32
def setup(self):
block_out_channels = self.block_out_channels
# in
self.conv_in = nn.Conv(
block_out_channels[0],
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
# downsampling
down_blocks = []
output_channel = block_out_channels[0]
for i, _ in enumerate(self.down_block_types):
input_channel = output_channel
output_channel = block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
down_block = FlaxDownEncoderBlock2D(
in_channels=input_channel,
out_channels=output_channel,
num_layers=self.layers_per_block,
resnet_groups=self.norm_num_groups,
add_downsample=not is_final_block,
dtype=self.dtype,
)
down_blocks.append(down_block)
self.down_blocks = down_blocks
# middle
self.mid_block = FlaxUNetMidBlock2D(
in_channels=block_out_channels[-1],
resnet_groups=self.norm_num_groups,
num_attention_heads=None,
dtype=self.dtype,
)
# end
conv_out_channels = 2 * self.out_channels if self.double_z else self.out_channels
self.conv_norm_out = nn.GroupNorm(num_groups=self.norm_num_groups, epsilon=1e-6)
self.conv_out = nn.Conv(
conv_out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
def __call__(self, sample, deterministic: bool = True):
# in
sample = self.conv_in(sample)
# downsampling
for block in self.down_blocks:
sample = block(sample, deterministic=deterministic)
# middle
sample = self.mid_block(sample, deterministic=deterministic)
# end
sample = self.conv_norm_out(sample)
sample = nn.swish(sample)
sample = self.conv_out(sample)
return sample
class FlaxDecoder(nn.Module):
r"""
Flax Implementation of VAE Decoder.
This model is a Flax Linen [flax.linen.Module](https://flax.readthedocs.io/en/latest/flax.linen.html#module)
subclass. Use it as a regular Flax linen Module and refer to the Flax documentation for all matter related to
general usage and behavior.
Finally, this model supports inherent JAX features such as:
- [Just-In-Time (JIT) compilation](https://jax.readthedocs.io/en/latest/jax.html#just-in-time-compilation-jit)
- [Automatic Differentiation](https://jax.readthedocs.io/en/latest/jax.html#automatic-differentiation)
- [Vectorization](https://jax.readthedocs.io/en/latest/jax.html#vectorization-vmap)
- [Parallelization](https://jax.readthedocs.io/en/latest/jax.html#parallelization-pmap)
Parameters:
in_channels (:obj:`int`, *optional*, defaults to 3):
Input channels
out_channels (:obj:`int`, *optional*, defaults to 3):
Output channels
up_block_types (:obj:`Tuple[str]`, *optional*, defaults to `(UpDecoderBlock2D)`):
UpDecoder block type
block_out_channels (:obj:`Tuple[str]`, *optional*, defaults to `(64,)`):
Tuple containing the number of output channels for each block
layers_per_block (:obj:`int`, *optional*, defaults to `2`):
Number of Resnet layer for each block
norm_num_groups (:obj:`int`, *optional*, defaults to `32`):
norm num group
act_fn (:obj:`str`, *optional*, defaults to `silu`):
Activation function
double_z (:obj:`bool`, *optional*, defaults to `False`):
Whether to double the last output channels
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
parameters `dtype`
"""
in_channels: int = 3
out_channels: int = 3
up_block_types: Tuple[str] = ("UpDecoderBlock2D",)
block_out_channels: int = (64,)
layers_per_block: int = 2
norm_num_groups: int = 32
act_fn: str = "silu"
dtype: jnp.dtype = jnp.float32
def setup(self):
block_out_channels = self.block_out_channels
# z to block_in
self.conv_in = nn.Conv(
block_out_channels[-1],
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
# middle
self.mid_block = FlaxUNetMidBlock2D(
in_channels=block_out_channels[-1],
resnet_groups=self.norm_num_groups,
num_attention_heads=None,
dtype=self.dtype,
)
# upsampling
reversed_block_out_channels = list(reversed(block_out_channels))
output_channel = reversed_block_out_channels[0]
up_blocks = []
for i, _ in enumerate(self.up_block_types):
prev_output_channel = output_channel
output_channel = reversed_block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
up_block = FlaxUpDecoderBlock2D(
in_channels=prev_output_channel,
out_channels=output_channel,
num_layers=self.layers_per_block + 1,
resnet_groups=self.norm_num_groups,
add_upsample=not is_final_block,
dtype=self.dtype,
)
up_blocks.append(up_block)
prev_output_channel = output_channel
self.up_blocks = up_blocks
# end
self.conv_norm_out = nn.GroupNorm(num_groups=self.norm_num_groups, epsilon=1e-6)
self.conv_out = nn.Conv(
self.out_channels,
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
def __call__(self, sample, deterministic: bool = True):
# z to block_in
sample = self.conv_in(sample)
# middle
sample = self.mid_block(sample, deterministic=deterministic)
# upsampling
for block in self.up_blocks:
sample = block(sample, deterministic=deterministic)
sample = self.conv_norm_out(sample)
sample = nn.swish(sample)
sample = self.conv_out(sample)
return sample
class FlaxDiagonalGaussianDistribution(object):
def __init__(self, parameters, deterministic=False):
# Last axis to account for channels-last
self.mean, self.logvar = jnp.split(parameters, 2, axis=-1)
self.logvar = jnp.clip(self.logvar, -30.0, 20.0)
self.deterministic = deterministic
self.std = jnp.exp(0.5 * self.logvar)
self.var = jnp.exp(self.logvar)
if self.deterministic:
self.var = self.std = jnp.zeros_like(self.mean)
def sample(self, key):
return self.mean + self.std * jax.random.normal(key, self.mean.shape)
def kl(self, other=None):
if self.deterministic:
return jnp.array([0.0])
if other is None:
return 0.5 * jnp.sum(self.mean**2 + self.var - 1.0 - self.logvar, axis=[1, 2, 3])
return 0.5 * jnp.sum(
jnp.square(self.mean - other.mean) / other.var + self.var / other.var - 1.0 - self.logvar + other.logvar,
axis=[1, 2, 3],
)
def nll(self, sample, axis=[1, 2, 3]):
if self.deterministic:
return jnp.array([0.0])
logtwopi = jnp.log(2.0 * jnp.pi)
return 0.5 * jnp.sum(logtwopi + self.logvar + jnp.square(sample - self.mean) / self.var, axis=axis)
def mode(self):
return self.mean
@flax_register_to_config
class FlaxAutoencoderKL(nn.Module, FlaxModelMixin, ConfigMixin):
r"""
Flax implementation of a VAE model with KL loss for decoding latent representations.
This model inherits from [`FlaxModelMixin`]. Check the superclass documentation for it's generic methods
implemented for all models (such as downloading or saving).
This model is a Flax Linen [flax.linen.Module](https://flax.readthedocs.io/en/latest/flax.linen.html#module)
subclass. Use it as a regular Flax Linen module and refer to the Flax documentation for all matter related to its
general usage and behavior.
Inherent JAX features such as the following are supported:
- [Just-In-Time (JIT) compilation](https://jax.readthedocs.io/en/latest/jax.html#just-in-time-compilation-jit)
- [Automatic Differentiation](https://jax.readthedocs.io/en/latest/jax.html#automatic-differentiation)
- [Vectorization](https://jax.readthedocs.io/en/latest/jax.html#vectorization-vmap)
- [Parallelization](https://jax.readthedocs.io/en/latest/jax.html#parallelization-pmap)
Parameters:
in_channels (`int`, *optional*, defaults to 3):
Number of channels in the input image.
out_channels (`int`, *optional*, defaults to 3):
Number of channels in the output.
down_block_types (`Tuple[str]`, *optional*, defaults to `(DownEncoderBlock2D)`):
Tuple of downsample block types.
up_block_types (`Tuple[str]`, *optional*, defaults to `(UpDecoderBlock2D)`):
Tuple of upsample block types.
block_out_channels (`Tuple[str]`, *optional*, defaults to `(64,)`):
Tuple of block output channels.
layers_per_block (`int`, *optional*, defaults to `2`):
Number of ResNet layer for each block.
act_fn (`str`, *optional*, defaults to `silu`):
The activation function to use.
latent_channels (`int`, *optional*, defaults to `4`):
Number of channels in the latent space.
norm_num_groups (`int`, *optional*, defaults to `32`):
The number of groups for normalization.
sample_size (`int`, *optional*, defaults to 32):
Sample input size.
scaling_factor (`float`, *optional*, defaults to 0.18215):
The component-wise standard deviation of the trained latent space computed using the first batch of the
training set. This is used to scale the latent space to have unit variance when training the diffusion
model. The latents are scaled with the formula `z = z * scaling_factor` before being passed to the
diffusion model. When decoding, the latents are scaled back to the original scale with the formula: `z = 1
/ scaling_factor * z`. For more details, refer to sections 4.3.2 and D.1 of the [High-Resolution Image
Synthesis with Latent Diffusion Models](https://arxiv.org/abs/2112.10752) paper.
dtype (`jnp.dtype`, *optional*, defaults to `jnp.float32`):
The `dtype` of the parameters.
"""
in_channels: int = 3
out_channels: int = 3
down_block_types: Tuple[str] = ("DownEncoderBlock2D",)
up_block_types: Tuple[str] = ("UpDecoderBlock2D",)
block_out_channels: Tuple[int] = (64,)
layers_per_block: int = 1
act_fn: str = "silu"
latent_channels: int = 4
norm_num_groups: int = 32
sample_size: int = 32
scaling_factor: float = 0.18215
dtype: jnp.dtype = jnp.float32
def setup(self):
self.encoder = FlaxEncoder(
in_channels=self.config.in_channels,
out_channels=self.config.latent_channels,
down_block_types=self.config.down_block_types,
block_out_channels=self.config.block_out_channels,
layers_per_block=self.config.layers_per_block,
act_fn=self.config.act_fn,
norm_num_groups=self.config.norm_num_groups,
double_z=True,
dtype=self.dtype,
)
self.decoder = FlaxDecoder(
in_channels=self.config.latent_channels,
out_channels=self.config.out_channels,
up_block_types=self.config.up_block_types,
block_out_channels=self.config.block_out_channels,
layers_per_block=self.config.layers_per_block,
norm_num_groups=self.config.norm_num_groups,
act_fn=self.config.act_fn,
dtype=self.dtype,
)
self.quant_conv = nn.Conv(
2 * self.config.latent_channels,
kernel_size=(1, 1),
strides=(1, 1),
padding="VALID",
dtype=self.dtype,
)
self.post_quant_conv = nn.Conv(
self.config.latent_channels,
kernel_size=(1, 1),
strides=(1, 1),
padding="VALID",
dtype=self.dtype,
)
def init_weights(self, rng: jax.random.KeyArray) -> FrozenDict:
# init input tensors
sample_shape = (1, self.in_channels, self.sample_size, self.sample_size)
sample = jnp.zeros(sample_shape, dtype=jnp.float32)
params_rng, dropout_rng, gaussian_rng = jax.random.split(rng, 3)
rngs = {"params": params_rng, "dropout": dropout_rng, "gaussian": gaussian_rng}
return self.init(rngs, sample)["params"]
def encode(self, sample, deterministic: bool = True, return_dict: bool = True):
sample = jnp.transpose(sample, (0, 2, 3, 1))
hidden_states = self.encoder(sample, deterministic=deterministic)
moments = self.quant_conv(hidden_states)
posterior = FlaxDiagonalGaussianDistribution(moments)
if not return_dict:
return (posterior,)
return FlaxAutoencoderKLOutput(latent_dist=posterior)
def decode(self, latents, deterministic: bool = True, return_dict: bool = True):
if latents.shape[-1] != self.config.latent_channels:
latents = jnp.transpose(latents, (0, 2, 3, 1))
hidden_states = self.post_quant_conv(latents)
hidden_states = self.decoder(hidden_states, deterministic=deterministic)
hidden_states = jnp.transpose(hidden_states, (0, 3, 1, 2))
if not return_dict:
return (hidden_states,)
return FlaxDecoderOutput(sample=hidden_states)
def __call__(self, sample, sample_posterior=False, deterministic: bool = True, return_dict: bool = True):
posterior = self.encode(sample, deterministic=deterministic, return_dict=return_dict)
if sample_posterior:
rng = self.make_rng("gaussian")
hidden_states = posterior.latent_dist.sample(rng)
else:
hidden_states = posterior.latent_dist.mode()
sample = self.decode(hidden_states, return_dict=return_dict).sample
if not return_dict:
return (sample,)
return FlaxDecoderOutput(sample=sample)
| diffusers-main | src/diffusers/models/vae_flax.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import torch
import torch.nn as nn
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.accelerate_utils import apply_forward_hook
from .modeling_utils import ModelMixin
from .vae import Decoder, DecoderOutput, Encoder, VectorQuantizer
@dataclass
class VQEncoderOutput(BaseOutput):
"""
Output of VQModel encoding method.
Args:
latents (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`):
The encoded output sample from the last layer of the model.
"""
latents: torch.FloatTensor
class VQModel(ModelMixin, ConfigMixin):
r"""
A VQ-VAE model for decoding latent representations.
This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
for all models (such as downloading or saving).
Parameters:
in_channels (int, *optional*, defaults to 3): Number of channels in the input image.
out_channels (int, *optional*, defaults to 3): Number of channels in the output.
down_block_types (`Tuple[str]`, *optional*, defaults to `("DownEncoderBlock2D",)`):
Tuple of downsample block types.
up_block_types (`Tuple[str]`, *optional*, defaults to `("UpDecoderBlock2D",)`):
Tuple of upsample block types.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(64,)`):
Tuple of block output channels.
act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
latent_channels (`int`, *optional*, defaults to `3`): Number of channels in the latent space.
sample_size (`int`, *optional*, defaults to `32`): Sample input size.
num_vq_embeddings (`int`, *optional*, defaults to `256`): Number of codebook vectors in the VQ-VAE.
vq_embed_dim (`int`, *optional*): Hidden dim of codebook vectors in the VQ-VAE.
scaling_factor (`float`, *optional*, defaults to `0.18215`):
The component-wise standard deviation of the trained latent space computed using the first batch of the
training set. This is used to scale the latent space to have unit variance when training the diffusion
model. The latents are scaled with the formula `z = z * scaling_factor` before being passed to the
diffusion model. When decoding, the latents are scaled back to the original scale with the formula: `z = 1
/ scaling_factor * z`. For more details, refer to sections 4.3.2 and D.1 of the [High-Resolution Image
Synthesis with Latent Diffusion Models](https://arxiv.org/abs/2112.10752) paper.
"""
@register_to_config
def __init__(
self,
in_channels: int = 3,
out_channels: int = 3,
down_block_types: Tuple[str] = ("DownEncoderBlock2D",),
up_block_types: Tuple[str] = ("UpDecoderBlock2D",),
block_out_channels: Tuple[int] = (64,),
layers_per_block: int = 1,
act_fn: str = "silu",
latent_channels: int = 3,
sample_size: int = 32,
num_vq_embeddings: int = 256,
norm_num_groups: int = 32,
vq_embed_dim: Optional[int] = None,
scaling_factor: float = 0.18215,
norm_type: str = "group", # group, spatial
):
super().__init__()
# pass init params to Encoder
self.encoder = Encoder(
in_channels=in_channels,
out_channels=latent_channels,
down_block_types=down_block_types,
block_out_channels=block_out_channels,
layers_per_block=layers_per_block,
act_fn=act_fn,
norm_num_groups=norm_num_groups,
double_z=False,
)
vq_embed_dim = vq_embed_dim if vq_embed_dim is not None else latent_channels
self.quant_conv = nn.Conv2d(latent_channels, vq_embed_dim, 1)
self.quantize = VectorQuantizer(num_vq_embeddings, vq_embed_dim, beta=0.25, remap=None, sane_index_shape=False)
self.post_quant_conv = nn.Conv2d(vq_embed_dim, latent_channels, 1)
# pass init params to Decoder
self.decoder = Decoder(
in_channels=latent_channels,
out_channels=out_channels,
up_block_types=up_block_types,
block_out_channels=block_out_channels,
layers_per_block=layers_per_block,
act_fn=act_fn,
norm_num_groups=norm_num_groups,
norm_type=norm_type,
)
@apply_forward_hook
def encode(self, x: torch.FloatTensor, return_dict: bool = True) -> VQEncoderOutput:
h = self.encoder(x)
h = self.quant_conv(h)
if not return_dict:
return (h,)
return VQEncoderOutput(latents=h)
@apply_forward_hook
def decode(
self, h: torch.FloatTensor, force_not_quantize: bool = False, return_dict: bool = True
) -> Union[DecoderOutput, torch.FloatTensor]:
# also go through quantization layer
if not force_not_quantize:
quant, _, _ = self.quantize(h)
else:
quant = h
quant2 = self.post_quant_conv(quant)
dec = self.decoder(quant2, quant if self.config.norm_type == "spatial" else None)
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
def forward(self, sample: torch.FloatTensor, return_dict: bool = True) -> Union[DecoderOutput, torch.FloatTensor]:
r"""
The [`VQModel`] forward method.
Args:
sample (`torch.FloatTensor`): Input sample.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`models.vq_model.VQEncoderOutput`] instead of a plain tuple.
Returns:
[`~models.vq_model.VQEncoderOutput`] or `tuple`:
If return_dict is True, a [`~models.vq_model.VQEncoderOutput`] is returned, otherwise a plain `tuple`
is returned.
"""
x = sample
h = self.encode(x).latents
dec = self.decode(h).sample
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
| diffusers-main | src/diffusers/models/vq_model.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional
import numpy as np
import torch
import torch.nn as nn
from ..utils import BaseOutput, is_torch_version
from ..utils.torch_utils import randn_tensor
from .activations import get_activation
from .attention_processor import SpatialNorm
from .unet_2d_blocks import AutoencoderTinyBlock, UNetMidBlock2D, get_down_block, get_up_block
@dataclass
class DecoderOutput(BaseOutput):
"""
Output of decoding method.
Args:
sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`):
The decoded output sample from the last layer of the model.
"""
sample: torch.FloatTensor
class Encoder(nn.Module):
def __init__(
self,
in_channels=3,
out_channels=3,
down_block_types=("DownEncoderBlock2D",),
block_out_channels=(64,),
layers_per_block=2,
norm_num_groups=32,
act_fn="silu",
double_z=True,
):
super().__init__()
self.layers_per_block = layers_per_block
self.conv_in = nn.Conv2d(
in_channels,
block_out_channels[0],
kernel_size=3,
stride=1,
padding=1,
)
self.mid_block = None
self.down_blocks = nn.ModuleList([])
# down
output_channel = block_out_channels[0]
for i, down_block_type in enumerate(down_block_types):
input_channel = output_channel
output_channel = block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
down_block = get_down_block(
down_block_type,
num_layers=self.layers_per_block,
in_channels=input_channel,
out_channels=output_channel,
add_downsample=not is_final_block,
resnet_eps=1e-6,
downsample_padding=0,
resnet_act_fn=act_fn,
resnet_groups=norm_num_groups,
attention_head_dim=output_channel,
temb_channels=None,
)
self.down_blocks.append(down_block)
# mid
self.mid_block = UNetMidBlock2D(
in_channels=block_out_channels[-1],
resnet_eps=1e-6,
resnet_act_fn=act_fn,
output_scale_factor=1,
resnet_time_scale_shift="default",
attention_head_dim=block_out_channels[-1],
resnet_groups=norm_num_groups,
temb_channels=None,
)
# out
self.conv_norm_out = nn.GroupNorm(num_channels=block_out_channels[-1], num_groups=norm_num_groups, eps=1e-6)
self.conv_act = nn.SiLU()
conv_out_channels = 2 * out_channels if double_z else out_channels
self.conv_out = nn.Conv2d(block_out_channels[-1], conv_out_channels, 3, padding=1)
self.gradient_checkpointing = False
def forward(self, x):
sample = x
sample = self.conv_in(sample)
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
# down
if is_torch_version(">=", "1.11.0"):
for down_block in self.down_blocks:
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(down_block), sample, use_reentrant=False
)
# middle
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(self.mid_block), sample, use_reentrant=False
)
else:
for down_block in self.down_blocks:
sample = torch.utils.checkpoint.checkpoint(create_custom_forward(down_block), sample)
# middle
sample = torch.utils.checkpoint.checkpoint(create_custom_forward(self.mid_block), sample)
else:
# down
for down_block in self.down_blocks:
sample = down_block(sample)
# middle
sample = self.mid_block(sample)
# post-process
sample = self.conv_norm_out(sample)
sample = self.conv_act(sample)
sample = self.conv_out(sample)
return sample
class Decoder(nn.Module):
def __init__(
self,
in_channels=3,
out_channels=3,
up_block_types=("UpDecoderBlock2D",),
block_out_channels=(64,),
layers_per_block=2,
norm_num_groups=32,
act_fn="silu",
norm_type="group", # group, spatial
):
super().__init__()
self.layers_per_block = layers_per_block
self.conv_in = nn.Conv2d(
in_channels,
block_out_channels[-1],
kernel_size=3,
stride=1,
padding=1,
)
self.mid_block = None
self.up_blocks = nn.ModuleList([])
temb_channels = in_channels if norm_type == "spatial" else None
# mid
self.mid_block = UNetMidBlock2D(
in_channels=block_out_channels[-1],
resnet_eps=1e-6,
resnet_act_fn=act_fn,
output_scale_factor=1,
resnet_time_scale_shift="default" if norm_type == "group" else norm_type,
attention_head_dim=block_out_channels[-1],
resnet_groups=norm_num_groups,
temb_channels=temb_channels,
)
# up
reversed_block_out_channels = list(reversed(block_out_channels))
output_channel = reversed_block_out_channels[0]
for i, up_block_type in enumerate(up_block_types):
prev_output_channel = output_channel
output_channel = reversed_block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
up_block = get_up_block(
up_block_type,
num_layers=self.layers_per_block + 1,
in_channels=prev_output_channel,
out_channels=output_channel,
prev_output_channel=None,
add_upsample=not is_final_block,
resnet_eps=1e-6,
resnet_act_fn=act_fn,
resnet_groups=norm_num_groups,
attention_head_dim=output_channel,
temb_channels=temb_channels,
resnet_time_scale_shift=norm_type,
)
self.up_blocks.append(up_block)
prev_output_channel = output_channel
# out
if norm_type == "spatial":
self.conv_norm_out = SpatialNorm(block_out_channels[0], temb_channels)
else:
self.conv_norm_out = nn.GroupNorm(num_channels=block_out_channels[0], num_groups=norm_num_groups, eps=1e-6)
self.conv_act = nn.SiLU()
self.conv_out = nn.Conv2d(block_out_channels[0], out_channels, 3, padding=1)
self.gradient_checkpointing = False
def forward(self, z, latent_embeds=None):
sample = z
sample = self.conv_in(sample)
upscale_dtype = next(iter(self.up_blocks.parameters())).dtype
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
# middle
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(self.mid_block), sample, latent_embeds, use_reentrant=False
)
sample = sample.to(upscale_dtype)
# up
for up_block in self.up_blocks:
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(up_block), sample, latent_embeds, use_reentrant=False
)
else:
# middle
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(self.mid_block), sample, latent_embeds
)
sample = sample.to(upscale_dtype)
# up
for up_block in self.up_blocks:
sample = torch.utils.checkpoint.checkpoint(create_custom_forward(up_block), sample, latent_embeds)
else:
# middle
sample = self.mid_block(sample, latent_embeds)
sample = sample.to(upscale_dtype)
# up
for up_block in self.up_blocks:
sample = up_block(sample, latent_embeds)
# post-process
if latent_embeds is None:
sample = self.conv_norm_out(sample)
else:
sample = self.conv_norm_out(sample, latent_embeds)
sample = self.conv_act(sample)
sample = self.conv_out(sample)
return sample
class UpSample(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
) -> None:
super().__init__()
self.in_channels = in_channels
self.out_channels = out_channels
self.deconv = nn.ConvTranspose2d(in_channels, out_channels, kernel_size=4, stride=2, padding=1)
def forward(self, x: torch.FloatTensor) -> torch.FloatTensor:
x = torch.relu(x)
x = self.deconv(x)
return x
class MaskConditionEncoder(nn.Module):
"""
used in AsymmetricAutoencoderKL
"""
def __init__(
self,
in_ch: int,
out_ch: int = 192,
res_ch: int = 768,
stride: int = 16,
) -> None:
super().__init__()
channels = []
while stride > 1:
stride = stride // 2
in_ch_ = out_ch * 2
if out_ch > res_ch:
out_ch = res_ch
if stride == 1:
in_ch_ = res_ch
channels.append((in_ch_, out_ch))
out_ch *= 2
out_channels = []
for _in_ch, _out_ch in channels:
out_channels.append(_out_ch)
out_channels.append(channels[-1][0])
layers = []
in_ch_ = in_ch
for l in range(len(out_channels)):
out_ch_ = out_channels[l]
if l == 0 or l == 1:
layers.append(nn.Conv2d(in_ch_, out_ch_, kernel_size=3, stride=1, padding=1))
else:
layers.append(nn.Conv2d(in_ch_, out_ch_, kernel_size=4, stride=2, padding=1))
in_ch_ = out_ch_
self.layers = nn.Sequential(*layers)
def forward(self, x: torch.FloatTensor, mask=None) -> torch.FloatTensor:
out = {}
for l in range(len(self.layers)):
layer = self.layers[l]
x = layer(x)
out[str(tuple(x.shape))] = x
x = torch.relu(x)
return out
class MaskConditionDecoder(nn.Module):
"""The `MaskConditionDecoder` should be used in combination with [`AsymmetricAutoencoderKL`] to enhance the model's
decoder with a conditioner on the mask and masked image."""
def __init__(
self,
in_channels=3,
out_channels=3,
up_block_types=("UpDecoderBlock2D",),
block_out_channels=(64,),
layers_per_block=2,
norm_num_groups=32,
act_fn="silu",
norm_type="group", # group, spatial
):
super().__init__()
self.layers_per_block = layers_per_block
self.conv_in = nn.Conv2d(
in_channels,
block_out_channels[-1],
kernel_size=3,
stride=1,
padding=1,
)
self.mid_block = None
self.up_blocks = nn.ModuleList([])
temb_channels = in_channels if norm_type == "spatial" else None
# mid
self.mid_block = UNetMidBlock2D(
in_channels=block_out_channels[-1],
resnet_eps=1e-6,
resnet_act_fn=act_fn,
output_scale_factor=1,
resnet_time_scale_shift="default" if norm_type == "group" else norm_type,
attention_head_dim=block_out_channels[-1],
resnet_groups=norm_num_groups,
temb_channels=temb_channels,
)
# up
reversed_block_out_channels = list(reversed(block_out_channels))
output_channel = reversed_block_out_channels[0]
for i, up_block_type in enumerate(up_block_types):
prev_output_channel = output_channel
output_channel = reversed_block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
up_block = get_up_block(
up_block_type,
num_layers=self.layers_per_block + 1,
in_channels=prev_output_channel,
out_channels=output_channel,
prev_output_channel=None,
add_upsample=not is_final_block,
resnet_eps=1e-6,
resnet_act_fn=act_fn,
resnet_groups=norm_num_groups,
attention_head_dim=output_channel,
temb_channels=temb_channels,
resnet_time_scale_shift=norm_type,
)
self.up_blocks.append(up_block)
prev_output_channel = output_channel
# condition encoder
self.condition_encoder = MaskConditionEncoder(
in_ch=out_channels,
out_ch=block_out_channels[0],
res_ch=block_out_channels[-1],
)
# out
if norm_type == "spatial":
self.conv_norm_out = SpatialNorm(block_out_channels[0], temb_channels)
else:
self.conv_norm_out = nn.GroupNorm(num_channels=block_out_channels[0], num_groups=norm_num_groups, eps=1e-6)
self.conv_act = nn.SiLU()
self.conv_out = nn.Conv2d(block_out_channels[0], out_channels, 3, padding=1)
self.gradient_checkpointing = False
def forward(self, z, image=None, mask=None, latent_embeds=None):
sample = z
sample = self.conv_in(sample)
upscale_dtype = next(iter(self.up_blocks.parameters())).dtype
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
# middle
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(self.mid_block), sample, latent_embeds, use_reentrant=False
)
sample = sample.to(upscale_dtype)
# condition encoder
if image is not None and mask is not None:
masked_image = (1 - mask) * image
im_x = torch.utils.checkpoint.checkpoint(
create_custom_forward(self.condition_encoder), masked_image, mask, use_reentrant=False
)
# up
for up_block in self.up_blocks:
if image is not None and mask is not None:
sample_ = im_x[str(tuple(sample.shape))]
mask_ = nn.functional.interpolate(mask, size=sample.shape[-2:], mode="nearest")
sample = sample * mask_ + sample_ * (1 - mask_)
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(up_block), sample, latent_embeds, use_reentrant=False
)
if image is not None and mask is not None:
sample = sample * mask + im_x[str(tuple(sample.shape))] * (1 - mask)
else:
# middle
sample = torch.utils.checkpoint.checkpoint(
create_custom_forward(self.mid_block), sample, latent_embeds
)
sample = sample.to(upscale_dtype)
# condition encoder
if image is not None and mask is not None:
masked_image = (1 - mask) * image
im_x = torch.utils.checkpoint.checkpoint(
create_custom_forward(self.condition_encoder), masked_image, mask
)
# up
for up_block in self.up_blocks:
if image is not None and mask is not None:
sample_ = im_x[str(tuple(sample.shape))]
mask_ = nn.functional.interpolate(mask, size=sample.shape[-2:], mode="nearest")
sample = sample * mask_ + sample_ * (1 - mask_)
sample = torch.utils.checkpoint.checkpoint(create_custom_forward(up_block), sample, latent_embeds)
if image is not None and mask is not None:
sample = sample * mask + im_x[str(tuple(sample.shape))] * (1 - mask)
else:
# middle
sample = self.mid_block(sample, latent_embeds)
sample = sample.to(upscale_dtype)
# condition encoder
if image is not None and mask is not None:
masked_image = (1 - mask) * image
im_x = self.condition_encoder(masked_image, mask)
# up
for up_block in self.up_blocks:
if image is not None and mask is not None:
sample_ = im_x[str(tuple(sample.shape))]
mask_ = nn.functional.interpolate(mask, size=sample.shape[-2:], mode="nearest")
sample = sample * mask_ + sample_ * (1 - mask_)
sample = up_block(sample, latent_embeds)
if image is not None and mask is not None:
sample = sample * mask + im_x[str(tuple(sample.shape))] * (1 - mask)
# post-process
if latent_embeds is None:
sample = self.conv_norm_out(sample)
else:
sample = self.conv_norm_out(sample, latent_embeds)
sample = self.conv_act(sample)
sample = self.conv_out(sample)
return sample
class VectorQuantizer(nn.Module):
"""
Improved version over VectorQuantizer, can be used as a drop-in replacement. Mostly avoids costly matrix
multiplications and allows for post-hoc remapping of indices.
"""
# NOTE: due to a bug the beta term was applied to the wrong term. for
# backwards compatibility we use the buggy version by default, but you can
# specify legacy=False to fix it.
def __init__(
self, n_e, vq_embed_dim, beta, remap=None, unknown_index="random", sane_index_shape=False, legacy=True
):
super().__init__()
self.n_e = n_e
self.vq_embed_dim = vq_embed_dim
self.beta = beta
self.legacy = legacy
self.embedding = nn.Embedding(self.n_e, self.vq_embed_dim)
self.embedding.weight.data.uniform_(-1.0 / self.n_e, 1.0 / self.n_e)
self.remap = remap
if self.remap is not None:
self.register_buffer("used", torch.tensor(np.load(self.remap)))
self.re_embed = self.used.shape[0]
self.unknown_index = unknown_index # "random" or "extra" or integer
if self.unknown_index == "extra":
self.unknown_index = self.re_embed
self.re_embed = self.re_embed + 1
print(
f"Remapping {self.n_e} indices to {self.re_embed} indices. "
f"Using {self.unknown_index} for unknown indices."
)
else:
self.re_embed = n_e
self.sane_index_shape = sane_index_shape
def remap_to_used(self, inds):
ishape = inds.shape
assert len(ishape) > 1
inds = inds.reshape(ishape[0], -1)
used = self.used.to(inds)
match = (inds[:, :, None] == used[None, None, ...]).long()
new = match.argmax(-1)
unknown = match.sum(2) < 1
if self.unknown_index == "random":
new[unknown] = torch.randint(0, self.re_embed, size=new[unknown].shape).to(device=new.device)
else:
new[unknown] = self.unknown_index
return new.reshape(ishape)
def unmap_to_all(self, inds):
ishape = inds.shape
assert len(ishape) > 1
inds = inds.reshape(ishape[0], -1)
used = self.used.to(inds)
if self.re_embed > self.used.shape[0]: # extra token
inds[inds >= self.used.shape[0]] = 0 # simply set to zero
back = torch.gather(used[None, :][inds.shape[0] * [0], :], 1, inds)
return back.reshape(ishape)
def forward(self, z):
# reshape z -> (batch, height, width, channel) and flatten
z = z.permute(0, 2, 3, 1).contiguous()
z_flattened = z.view(-1, self.vq_embed_dim)
# distances from z to embeddings e_j (z - e)^2 = z^2 + e^2 - 2 e * z
min_encoding_indices = torch.argmin(torch.cdist(z_flattened, self.embedding.weight), dim=1)
z_q = self.embedding(min_encoding_indices).view(z.shape)
perplexity = None
min_encodings = None
# compute loss for embedding
if not self.legacy:
loss = self.beta * torch.mean((z_q.detach() - z) ** 2) + torch.mean((z_q - z.detach()) ** 2)
else:
loss = torch.mean((z_q.detach() - z) ** 2) + self.beta * torch.mean((z_q - z.detach()) ** 2)
# preserve gradients
z_q = z + (z_q - z).detach()
# reshape back to match original input shape
z_q = z_q.permute(0, 3, 1, 2).contiguous()
if self.remap is not None:
min_encoding_indices = min_encoding_indices.reshape(z.shape[0], -1) # add batch axis
min_encoding_indices = self.remap_to_used(min_encoding_indices)
min_encoding_indices = min_encoding_indices.reshape(-1, 1) # flatten
if self.sane_index_shape:
min_encoding_indices = min_encoding_indices.reshape(z_q.shape[0], z_q.shape[2], z_q.shape[3])
return z_q, loss, (perplexity, min_encodings, min_encoding_indices)
def get_codebook_entry(self, indices, shape):
# shape specifying (batch, height, width, channel)
if self.remap is not None:
indices = indices.reshape(shape[0], -1) # add batch axis
indices = self.unmap_to_all(indices)
indices = indices.reshape(-1) # flatten again
# get quantized latent vectors
z_q = self.embedding(indices)
if shape is not None:
z_q = z_q.view(shape)
# reshape back to match original input shape
z_q = z_q.permute(0, 3, 1, 2).contiguous()
return z_q
class DiagonalGaussianDistribution(object):
def __init__(self, parameters, deterministic=False):
self.parameters = parameters
self.mean, self.logvar = torch.chunk(parameters, 2, dim=1)
self.logvar = torch.clamp(self.logvar, -30.0, 20.0)
self.deterministic = deterministic
self.std = torch.exp(0.5 * self.logvar)
self.var = torch.exp(self.logvar)
if self.deterministic:
self.var = self.std = torch.zeros_like(
self.mean, device=self.parameters.device, dtype=self.parameters.dtype
)
def sample(self, generator: Optional[torch.Generator] = None) -> torch.FloatTensor:
# make sure sample is on the same device as the parameters and has same dtype
sample = randn_tensor(
self.mean.shape, generator=generator, device=self.parameters.device, dtype=self.parameters.dtype
)
x = self.mean + self.std * sample
return x
def kl(self, other=None):
if self.deterministic:
return torch.Tensor([0.0])
else:
if other is None:
return 0.5 * torch.sum(torch.pow(self.mean, 2) + self.var - 1.0 - self.logvar, dim=[1, 2, 3])
else:
return 0.5 * torch.sum(
torch.pow(self.mean - other.mean, 2) / other.var
+ self.var / other.var
- 1.0
- self.logvar
+ other.logvar,
dim=[1, 2, 3],
)
def nll(self, sample, dims=[1, 2, 3]):
if self.deterministic:
return torch.Tensor([0.0])
logtwopi = np.log(2.0 * np.pi)
return 0.5 * torch.sum(logtwopi + self.logvar + torch.pow(sample - self.mean, 2) / self.var, dim=dims)
def mode(self):
return self.mean
class EncoderTiny(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
num_blocks: int,
block_out_channels: int,
act_fn: str,
):
super().__init__()
layers = []
for i, num_block in enumerate(num_blocks):
num_channels = block_out_channels[i]
if i == 0:
layers.append(nn.Conv2d(in_channels, num_channels, kernel_size=3, padding=1))
else:
layers.append(nn.Conv2d(num_channels, num_channels, kernel_size=3, padding=1, stride=2, bias=False))
for _ in range(num_block):
layers.append(AutoencoderTinyBlock(num_channels, num_channels, act_fn))
layers.append(nn.Conv2d(block_out_channels[-1], out_channels, kernel_size=3, padding=1))
self.layers = nn.Sequential(*layers)
self.gradient_checkpointing = False
def forward(self, x):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
x = torch.utils.checkpoint.checkpoint(create_custom_forward(self.layers), x, use_reentrant=False)
else:
x = torch.utils.checkpoint.checkpoint(create_custom_forward(self.layers), x)
else:
# scale image from [-1, 1] to [0, 1] to match TAESD convention
x = self.layers(x.add(1).div(2))
return x
class DecoderTiny(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
num_blocks: int,
block_out_channels: int,
upsampling_scaling_factor: int,
act_fn: str,
):
super().__init__()
layers = [
nn.Conv2d(in_channels, block_out_channels[0], kernel_size=3, padding=1),
get_activation(act_fn),
]
for i, num_block in enumerate(num_blocks):
is_final_block = i == (len(num_blocks) - 1)
num_channels = block_out_channels[i]
for _ in range(num_block):
layers.append(AutoencoderTinyBlock(num_channels, num_channels, act_fn))
if not is_final_block:
layers.append(nn.Upsample(scale_factor=upsampling_scaling_factor))
conv_out_channel = num_channels if not is_final_block else out_channels
layers.append(nn.Conv2d(num_channels, conv_out_channel, kernel_size=3, padding=1, bias=is_final_block))
self.layers = nn.Sequential(*layers)
self.gradient_checkpointing = False
def forward(self, x):
# Clamp.
x = torch.tanh(x / 3) * 3
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
x = torch.utils.checkpoint.checkpoint(create_custom_forward(self.layers), x, use_reentrant=False)
else:
x = torch.utils.checkpoint.checkpoint(create_custom_forward(self.layers), x)
else:
x = self.layers(x)
# scale image from [0, 1] to [-1, 1] to match diffusers convention
return x.mul(2).sub(1)
| diffusers-main | src/diffusers/models/vae.py |
# Copyright 2023 Ollin Boer Bohan and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Tuple, Union
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.accelerate_utils import apply_forward_hook
from .modeling_utils import ModelMixin
from .vae import DecoderOutput, DecoderTiny, EncoderTiny
@dataclass
class AutoencoderTinyOutput(BaseOutput):
"""
Output of AutoencoderTiny encoding method.
Args:
latents (`torch.Tensor`): Encoded outputs of the `Encoder`.
"""
latents: torch.Tensor
class AutoencoderTiny(ModelMixin, ConfigMixin):
r"""
A tiny distilled VAE model for encoding images into latents and decoding latent representations into images.
[`AutoencoderTiny`] is a wrapper around the original implementation of `TAESD`.
This model inherits from [`ModelMixin`]. Check the superclass documentation for its generic methods implemented for
all models (such as downloading or saving).
Parameters:
in_channels (`int`, *optional*, defaults to 3): Number of channels in the input image.
out_channels (`int`, *optional*, defaults to 3): Number of channels in the output.
encoder_block_out_channels (`Tuple[int]`, *optional*, defaults to `(64, 64, 64, 64)`):
Tuple of integers representing the number of output channels for each encoder block. The length of the
tuple should be equal to the number of encoder blocks.
decoder_block_out_channels (`Tuple[int]`, *optional*, defaults to `(64, 64, 64, 64)`):
Tuple of integers representing the number of output channels for each decoder block. The length of the
tuple should be equal to the number of decoder blocks.
act_fn (`str`, *optional*, defaults to `"relu"`):
Activation function to be used throughout the model.
latent_channels (`int`, *optional*, defaults to 4):
Number of channels in the latent representation. The latent space acts as a compressed representation of
the input image.
upsampling_scaling_factor (`int`, *optional*, defaults to 2):
Scaling factor for upsampling in the decoder. It determines the size of the output image during the
upsampling process.
num_encoder_blocks (`Tuple[int]`, *optional*, defaults to `(1, 3, 3, 3)`):
Tuple of integers representing the number of encoder blocks at each stage of the encoding process. The
length of the tuple should be equal to the number of stages in the encoder. Each stage has a different
number of encoder blocks.
num_decoder_blocks (`Tuple[int]`, *optional*, defaults to `(3, 3, 3, 1)`):
Tuple of integers representing the number of decoder blocks at each stage of the decoding process. The
length of the tuple should be equal to the number of stages in the decoder. Each stage has a different
number of decoder blocks.
latent_magnitude (`float`, *optional*, defaults to 3.0):
Magnitude of the latent representation. This parameter scales the latent representation values to control
the extent of information preservation.
latent_shift (float, *optional*, defaults to 0.5):
Shift applied to the latent representation. This parameter controls the center of the latent space.
scaling_factor (`float`, *optional*, defaults to 1.0):
The component-wise standard deviation of the trained latent space computed using the first batch of the
training set. This is used to scale the latent space to have unit variance when training the diffusion
model. The latents are scaled with the formula `z = z * scaling_factor` before being passed to the
diffusion model. When decoding, the latents are scaled back to the original scale with the formula: `z = 1
/ scaling_factor * z`. For more details, refer to sections 4.3.2 and D.1 of the [High-Resolution Image
Synthesis with Latent Diffusion Models](https://arxiv.org/abs/2112.10752) paper. For this Autoencoder,
however, no such scaling factor was used, hence the value of 1.0 as the default.
force_upcast (`bool`, *optional*, default to `False`):
If enabled it will force the VAE to run in float32 for high image resolution pipelines, such as SD-XL. VAE
can be fine-tuned / trained to a lower range without losing too much precision, in which case
`force_upcast` can be set to `False` (see this fp16-friendly
[AutoEncoder](https://huggingface.co/madebyollin/sdxl-vae-fp16-fix)).
"""
_supports_gradient_checkpointing = True
@register_to_config
def __init__(
self,
in_channels=3,
out_channels=3,
encoder_block_out_channels: Tuple[int] = (64, 64, 64, 64),
decoder_block_out_channels: Tuple[int] = (64, 64, 64, 64),
act_fn: str = "relu",
latent_channels: int = 4,
upsampling_scaling_factor: int = 2,
num_encoder_blocks: Tuple[int] = (1, 3, 3, 3),
num_decoder_blocks: Tuple[int] = (3, 3, 3, 1),
latent_magnitude: int = 3,
latent_shift: float = 0.5,
force_upcast: float = False,
scaling_factor: float = 1.0,
):
super().__init__()
if len(encoder_block_out_channels) != len(num_encoder_blocks):
raise ValueError("`encoder_block_out_channels` should have the same length as `num_encoder_blocks`.")
if len(decoder_block_out_channels) != len(num_decoder_blocks):
raise ValueError("`decoder_block_out_channels` should have the same length as `num_decoder_blocks`.")
self.encoder = EncoderTiny(
in_channels=in_channels,
out_channels=latent_channels,
num_blocks=num_encoder_blocks,
block_out_channels=encoder_block_out_channels,
act_fn=act_fn,
)
self.decoder = DecoderTiny(
in_channels=latent_channels,
out_channels=out_channels,
num_blocks=num_decoder_blocks,
block_out_channels=decoder_block_out_channels,
upsampling_scaling_factor=upsampling_scaling_factor,
act_fn=act_fn,
)
self.latent_magnitude = latent_magnitude
self.latent_shift = latent_shift
self.scaling_factor = scaling_factor
self.use_slicing = False
self.use_tiling = False
# only relevant if vae tiling is enabled
self.spatial_scale_factor = 2**out_channels
self.tile_overlap_factor = 0.125
self.tile_sample_min_size = 512
self.tile_latent_min_size = self.tile_sample_min_size // self.spatial_scale_factor
def _set_gradient_checkpointing(self, module, value=False):
if isinstance(module, (EncoderTiny, DecoderTiny)):
module.gradient_checkpointing = value
def scale_latents(self, x):
"""raw latents -> [0, 1]"""
return x.div(2 * self.latent_magnitude).add(self.latent_shift).clamp(0, 1)
def unscale_latents(self, x):
"""[0, 1] -> raw latents"""
return x.sub(self.latent_shift).mul(2 * self.latent_magnitude)
def enable_slicing(self):
r"""
Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to
compute decoding in several steps. This is useful to save some memory and allow larger batch sizes.
"""
self.use_slicing = True
def disable_slicing(self):
r"""
Disable sliced VAE decoding. If `enable_slicing` was previously enabled, this method will go back to computing
decoding in one step.
"""
self.use_slicing = False
def enable_tiling(self, use_tiling: bool = True):
r"""
Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to
compute decoding and encoding in several steps. This is useful for saving a large amount of memory and to allow
processing larger images.
"""
self.use_tiling = use_tiling
def disable_tiling(self):
r"""
Disable tiled VAE decoding. If `enable_tiling` was previously enabled, this method will go back to computing
decoding in one step.
"""
self.enable_tiling(False)
def _tiled_encode(self, x: torch.FloatTensor) -> torch.FloatTensor:
r"""Encode a batch of images using a tiled encoder.
When this option is enabled, the VAE will split the input tensor into tiles to compute encoding in several
steps. This is useful to keep memory use constant regardless of image size. To avoid tiling artifacts, the
tiles overlap and are blended together to form a smooth output.
Args:
x (`torch.FloatTensor`): Input batch of images.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.autoencoder_tiny.AutoencoderTinyOutput`] instead of a plain tuple.
Returns:
[`~models.autoencoder_tiny.AutoencoderTinyOutput`] or `tuple`:
If return_dict is True, a [`~models.autoencoder_tiny.AutoencoderTinyOutput`] is returned, otherwise a
plain `tuple` is returned.
"""
# scale of encoder output relative to input
sf = self.spatial_scale_factor
tile_size = self.tile_sample_min_size
# number of pixels to blend and to traverse between tile
blend_size = int(tile_size * self.tile_overlap_factor)
traverse_size = tile_size - blend_size
# tiles index (up/left)
ti = range(0, x.shape[-2], traverse_size)
tj = range(0, x.shape[-1], traverse_size)
# mask for blending
blend_masks = torch.stack(
torch.meshgrid([torch.arange(tile_size / sf) / (blend_size / sf - 1)] * 2, indexing="ij")
)
blend_masks = blend_masks.clamp(0, 1).to(x.device)
# output array
out = torch.zeros(x.shape[0], 4, x.shape[-2] // sf, x.shape[-1] // sf, device=x.device)
for i in ti:
for j in tj:
tile_in = x[..., i : i + tile_size, j : j + tile_size]
# tile result
tile_out = out[..., i // sf : (i + tile_size) // sf, j // sf : (j + tile_size) // sf]
tile = self.encoder(tile_in)
h, w = tile.shape[-2], tile.shape[-1]
# blend tile result into output
blend_mask_i = torch.ones_like(blend_masks[0]) if i == 0 else blend_masks[0]
blend_mask_j = torch.ones_like(blend_masks[1]) if j == 0 else blend_masks[1]
blend_mask = blend_mask_i * blend_mask_j
tile, blend_mask = tile[..., :h, :w], blend_mask[..., :h, :w]
tile_out.copy_(blend_mask * tile + (1 - blend_mask) * tile_out)
return out
def _tiled_decode(self, x: torch.FloatTensor) -> torch.FloatTensor:
r"""Encode a batch of images using a tiled encoder.
When this option is enabled, the VAE will split the input tensor into tiles to compute encoding in several
steps. This is useful to keep memory use constant regardless of image size. To avoid tiling artifacts, the
tiles overlap and are blended together to form a smooth output.
Args:
x (`torch.FloatTensor`): Input batch of images.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.autoencoder_tiny.AutoencoderTinyOutput`] instead of a plain tuple.
Returns:
[`~models.vae.DecoderOutput`] or `tuple`:
If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
returned.
"""
# scale of decoder output relative to input
sf = self.spatial_scale_factor
tile_size = self.tile_latent_min_size
# number of pixels to blend and to traverse between tiles
blend_size = int(tile_size * self.tile_overlap_factor)
traverse_size = tile_size - blend_size
# tiles index (up/left)
ti = range(0, x.shape[-2], traverse_size)
tj = range(0, x.shape[-1], traverse_size)
# mask for blending
blend_masks = torch.stack(
torch.meshgrid([torch.arange(tile_size * sf) / (blend_size * sf - 1)] * 2, indexing="ij")
)
blend_masks = blend_masks.clamp(0, 1).to(x.device)
# output array
out = torch.zeros(x.shape[0], 3, x.shape[-2] * sf, x.shape[-1] * sf, device=x.device)
for i in ti:
for j in tj:
tile_in = x[..., i : i + tile_size, j : j + tile_size]
# tile result
tile_out = out[..., i * sf : (i + tile_size) * sf, j * sf : (j + tile_size) * sf]
tile = self.decoder(tile_in)
h, w = tile.shape[-2], tile.shape[-1]
# blend tile result into output
blend_mask_i = torch.ones_like(blend_masks[0]) if i == 0 else blend_masks[0]
blend_mask_j = torch.ones_like(blend_masks[1]) if j == 0 else blend_masks[1]
blend_mask = (blend_mask_i * blend_mask_j)[..., :h, :w]
tile_out.copy_(blend_mask * tile + (1 - blend_mask) * tile_out)
return out
@apply_forward_hook
def encode(
self, x: torch.FloatTensor, return_dict: bool = True
) -> Union[AutoencoderTinyOutput, Tuple[torch.FloatTensor]]:
if self.use_slicing and x.shape[0] > 1:
output = [self._tiled_encode(x_slice) if self.use_tiling else self.encoder(x) for x_slice in x.split(1)]
output = torch.cat(output)
else:
output = self._tiled_encode(x) if self.use_tiling else self.encoder(x)
if not return_dict:
return (output,)
return AutoencoderTinyOutput(latents=output)
@apply_forward_hook
def decode(self, x: torch.FloatTensor, return_dict: bool = True) -> Union[DecoderOutput, Tuple[torch.FloatTensor]]:
if self.use_slicing and x.shape[0] > 1:
output = [self._tiled_decode(x_slice) if self.use_tiling else self.decoder(x) for x_slice in x.split(1)]
output = torch.cat(output)
else:
output = self._tiled_decode(x) if self.use_tiling else self.decoder(x)
if not return_dict:
return (output,)
return DecoderOutput(sample=output)
def forward(
self,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[DecoderOutput, Tuple[torch.FloatTensor]]:
r"""
Args:
sample (`torch.FloatTensor`): Input sample.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`DecoderOutput`] instead of a plain tuple.
"""
enc = self.encode(sample).latents
# scale latents to be in [0, 1], then quantize latents to a byte tensor,
# as if we were storing the latents in an RGBA uint8 image.
scaled_enc = self.scale_latents(enc).mul_(255).round_().byte()
# unquantize latents back into [0, 1], then unscale latents back to their original range,
# as if we were loading the latents from an RGBA uint8 image.
unscaled_enc = self.unscale_latents(scaled_enc / 255.0)
dec = self.decode(unscaled_enc)
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
| diffusers-main | src/diffusers/models/autoencoder_tiny.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Any, Dict, Optional, Tuple
import numpy as np
import torch
import torch.nn.functional as F
from torch import nn
from ..utils import is_torch_version, logging
from .activations import get_activation
from .attention import AdaGroupNorm
from .attention_processor import Attention, AttnAddedKVProcessor, AttnAddedKVProcessor2_0
from .dual_transformer_2d import DualTransformer2DModel
from .resnet import Downsample2D, FirDownsample2D, FirUpsample2D, KDownsample2D, KUpsample2D, ResnetBlock2D, Upsample2D
from .transformer_2d import Transformer2DModel
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
def get_down_block(
down_block_type,
num_layers,
in_channels,
out_channels,
temb_channels,
add_downsample,
resnet_eps,
resnet_act_fn,
transformer_layers_per_block=1,
num_attention_heads=None,
resnet_groups=None,
cross_attention_dim=None,
downsample_padding=None,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
resnet_time_scale_shift="default",
attention_type="default",
resnet_skip_time_act=False,
resnet_out_scale_factor=1.0,
cross_attention_norm=None,
attention_head_dim=None,
downsample_type=None,
dropout=0.0,
):
# If attn head dim is not defined, we default it to the number of heads
if attention_head_dim is None:
logger.warn(
f"It is recommended to provide `attention_head_dim` when calling `get_down_block`. Defaulting `attention_head_dim` to {num_attention_heads}."
)
attention_head_dim = num_attention_heads
down_block_type = down_block_type[7:] if down_block_type.startswith("UNetRes") else down_block_type
if down_block_type == "DownBlock2D":
return DownBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
downsample_padding=downsample_padding,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif down_block_type == "ResnetDownsampleBlock2D":
return ResnetDownsampleBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
resnet_time_scale_shift=resnet_time_scale_shift,
skip_time_act=resnet_skip_time_act,
output_scale_factor=resnet_out_scale_factor,
)
elif down_block_type == "AttnDownBlock2D":
if add_downsample is False:
downsample_type = None
else:
downsample_type = downsample_type or "conv" # default to 'conv'
return AttnDownBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
downsample_padding=downsample_padding,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
downsample_type=downsample_type,
)
elif down_block_type == "CrossAttnDownBlock2D":
if cross_attention_dim is None:
raise ValueError("cross_attention_dim must be specified for CrossAttnDownBlock2D")
return CrossAttnDownBlock2D(
num_layers=num_layers,
transformer_layers_per_block=transformer_layers_per_block,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
downsample_padding=downsample_padding,
cross_attention_dim=cross_attention_dim,
num_attention_heads=num_attention_heads,
dual_cross_attention=dual_cross_attention,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
resnet_time_scale_shift=resnet_time_scale_shift,
attention_type=attention_type,
)
elif down_block_type == "SimpleCrossAttnDownBlock2D":
if cross_attention_dim is None:
raise ValueError("cross_attention_dim must be specified for SimpleCrossAttnDownBlock2D")
return SimpleCrossAttnDownBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
cross_attention_dim=cross_attention_dim,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
skip_time_act=resnet_skip_time_act,
output_scale_factor=resnet_out_scale_factor,
only_cross_attention=only_cross_attention,
cross_attention_norm=cross_attention_norm,
)
elif down_block_type == "SkipDownBlock2D":
return SkipDownBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
downsample_padding=downsample_padding,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif down_block_type == "AttnSkipDownBlock2D":
return AttnSkipDownBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif down_block_type == "DownEncoderBlock2D":
return DownEncoderBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
downsample_padding=downsample_padding,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif down_block_type == "AttnDownEncoderBlock2D":
return AttnDownEncoderBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
downsample_padding=downsample_padding,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif down_block_type == "KDownBlock2D":
return KDownBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
)
elif down_block_type == "KCrossAttnDownBlock2D":
return KCrossAttnDownBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
cross_attention_dim=cross_attention_dim,
attention_head_dim=attention_head_dim,
add_self_attention=True if not add_downsample else False,
)
raise ValueError(f"{down_block_type} does not exist.")
def get_up_block(
up_block_type,
num_layers,
in_channels,
out_channels,
prev_output_channel,
temb_channels,
add_upsample,
resnet_eps,
resnet_act_fn,
transformer_layers_per_block=1,
num_attention_heads=None,
resnet_groups=None,
cross_attention_dim=None,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
resnet_time_scale_shift="default",
attention_type="default",
resnet_skip_time_act=False,
resnet_out_scale_factor=1.0,
cross_attention_norm=None,
attention_head_dim=None,
upsample_type=None,
dropout=0.0,
):
# If attn head dim is not defined, we default it to the number of heads
if attention_head_dim is None:
logger.warn(
f"It is recommended to provide `attention_head_dim` when calling `get_up_block`. Defaulting `attention_head_dim` to {num_attention_heads}."
)
attention_head_dim = num_attention_heads
up_block_type = up_block_type[7:] if up_block_type.startswith("UNetRes") else up_block_type
if up_block_type == "UpBlock2D":
return UpBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif up_block_type == "ResnetUpsampleBlock2D":
return ResnetUpsampleBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
resnet_time_scale_shift=resnet_time_scale_shift,
skip_time_act=resnet_skip_time_act,
output_scale_factor=resnet_out_scale_factor,
)
elif up_block_type == "CrossAttnUpBlock2D":
if cross_attention_dim is None:
raise ValueError("cross_attention_dim must be specified for CrossAttnUpBlock2D")
return CrossAttnUpBlock2D(
num_layers=num_layers,
transformer_layers_per_block=transformer_layers_per_block,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
cross_attention_dim=cross_attention_dim,
num_attention_heads=num_attention_heads,
dual_cross_attention=dual_cross_attention,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
resnet_time_scale_shift=resnet_time_scale_shift,
attention_type=attention_type,
)
elif up_block_type == "SimpleCrossAttnUpBlock2D":
if cross_attention_dim is None:
raise ValueError("cross_attention_dim must be specified for SimpleCrossAttnUpBlock2D")
return SimpleCrossAttnUpBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
cross_attention_dim=cross_attention_dim,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
skip_time_act=resnet_skip_time_act,
output_scale_factor=resnet_out_scale_factor,
only_cross_attention=only_cross_attention,
cross_attention_norm=cross_attention_norm,
)
elif up_block_type == "AttnUpBlock2D":
if add_upsample is False:
upsample_type = None
else:
upsample_type = upsample_type or "conv" # default to 'conv'
return AttnUpBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
dropout=dropout,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
upsample_type=upsample_type,
)
elif up_block_type == "SkipUpBlock2D":
return SkipUpBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif up_block_type == "AttnSkipUpBlock2D":
return AttnSkipUpBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
)
elif up_block_type == "UpDecoderBlock2D":
return UpDecoderBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
resnet_time_scale_shift=resnet_time_scale_shift,
temb_channels=temb_channels,
)
elif up_block_type == "AttnUpDecoderBlock2D":
return AttnUpDecoderBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
attention_head_dim=attention_head_dim,
resnet_time_scale_shift=resnet_time_scale_shift,
temb_channels=temb_channels,
)
elif up_block_type == "KUpBlock2D":
return KUpBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
)
elif up_block_type == "KCrossAttnUpBlock2D":
return KCrossAttnUpBlock2D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
dropout=dropout,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
cross_attention_dim=cross_attention_dim,
attention_head_dim=attention_head_dim,
)
raise ValueError(f"{up_block_type} does not exist.")
class AutoencoderTinyBlock(nn.Module):
def __init__(self, in_channels: int, out_channels: int, act_fn: str):
super().__init__()
act_fn = get_activation(act_fn)
self.conv = nn.Sequential(
nn.Conv2d(in_channels, out_channels, kernel_size=3, padding=1),
act_fn,
nn.Conv2d(out_channels, out_channels, kernel_size=3, padding=1),
act_fn,
nn.Conv2d(out_channels, out_channels, kernel_size=3, padding=1),
)
self.skip = (
nn.Conv2d(in_channels, out_channels, kernel_size=1, bias=False)
if in_channels != out_channels
else nn.Identity()
)
self.fuse = nn.ReLU()
def forward(self, x):
return self.fuse(self.conv(x) + self.skip(x))
class UNetMidBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default", # default, spatial
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
attn_groups: Optional[int] = None,
resnet_pre_norm: bool = True,
add_attention: bool = True,
attention_head_dim=1,
output_scale_factor=1.0,
):
super().__init__()
resnet_groups = resnet_groups if resnet_groups is not None else min(in_channels // 4, 32)
self.add_attention = add_attention
if attn_groups is None:
attn_groups = resnet_groups if resnet_time_scale_shift == "default" else None
# there is always at least one resnet
resnets = [
ResnetBlock2D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
]
attentions = []
if attention_head_dim is None:
logger.warn(
f"It is not recommend to pass `attention_head_dim=None`. Defaulting `attention_head_dim` to `in_channels`: {in_channels}."
)
attention_head_dim = in_channels
for _ in range(num_layers):
if self.add_attention:
attentions.append(
Attention(
in_channels,
heads=in_channels // attention_head_dim,
dim_head=attention_head_dim,
rescale_output_factor=output_scale_factor,
eps=resnet_eps,
norm_num_groups=attn_groups,
spatial_norm_dim=temb_channels if resnet_time_scale_shift == "spatial" else None,
residual_connection=True,
bias=True,
upcast_softmax=True,
_from_deprecated_attn_block=True,
)
)
else:
attentions.append(None)
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
def forward(self, hidden_states, temb=None):
hidden_states = self.resnets[0](hidden_states, temb)
for attn, resnet in zip(self.attentions, self.resnets[1:]):
if attn is not None:
hidden_states = attn(hidden_states, temb=temb)
hidden_states = resnet(hidden_states, temb)
return hidden_states
class UNetMidBlock2DCrossAttn(nn.Module):
def __init__(
self,
in_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
transformer_layers_per_block: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
num_attention_heads=1,
output_scale_factor=1.0,
cross_attention_dim=1280,
dual_cross_attention=False,
use_linear_projection=False,
upcast_attention=False,
attention_type="default",
):
super().__init__()
self.has_cross_attention = True
self.num_attention_heads = num_attention_heads
resnet_groups = resnet_groups if resnet_groups is not None else min(in_channels // 4, 32)
# there is always at least one resnet
resnets = [
ResnetBlock2D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
]
attentions = []
for _ in range(num_layers):
if not dual_cross_attention:
attentions.append(
Transformer2DModel(
num_attention_heads,
in_channels // num_attention_heads,
in_channels=in_channels,
num_layers=transformer_layers_per_block,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
use_linear_projection=use_linear_projection,
upcast_attention=upcast_attention,
attention_type=attention_type,
)
)
else:
attentions.append(
DualTransformer2DModel(
num_attention_heads,
in_channels // num_attention_heads,
in_channels=in_channels,
num_layers=1,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
)
)
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.FloatTensor,
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
) -> torch.FloatTensor:
lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0
hidden_states = self.resnets[0](hidden_states, temb, scale=lora_scale)
for attn, resnet in zip(self.attentions, self.resnets[1:]):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
ckpt_kwargs: Dict[str, Any] = {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
cross_attention_kwargs=cross_attention_kwargs,
attention_mask=attention_mask,
encoder_attention_mask=encoder_attention_mask,
return_dict=False,
)[0]
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet),
hidden_states,
temb,
**ckpt_kwargs,
)
else:
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
cross_attention_kwargs=cross_attention_kwargs,
attention_mask=attention_mask,
encoder_attention_mask=encoder_attention_mask,
return_dict=False,
)[0]
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
return hidden_states
class UNetMidBlock2DSimpleCrossAttn(nn.Module):
def __init__(
self,
in_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attention_head_dim=1,
output_scale_factor=1.0,
cross_attention_dim=1280,
skip_time_act=False,
only_cross_attention=False,
cross_attention_norm=None,
):
super().__init__()
self.has_cross_attention = True
self.attention_head_dim = attention_head_dim
resnet_groups = resnet_groups if resnet_groups is not None else min(in_channels // 4, 32)
self.num_heads = in_channels // self.attention_head_dim
# there is always at least one resnet
resnets = [
ResnetBlock2D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
)
]
attentions = []
for _ in range(num_layers):
processor = (
AttnAddedKVProcessor2_0() if hasattr(F, "scaled_dot_product_attention") else AttnAddedKVProcessor()
)
attentions.append(
Attention(
query_dim=in_channels,
cross_attention_dim=in_channels,
heads=self.num_heads,
dim_head=self.attention_head_dim,
added_kv_proj_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
bias=True,
upcast_softmax=True,
only_cross_attention=only_cross_attention,
cross_attention_norm=cross_attention_norm,
processor=processor,
)
)
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
def forward(
self,
hidden_states: torch.FloatTensor,
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
):
cross_attention_kwargs = cross_attention_kwargs if cross_attention_kwargs is not None else {}
lora_scale = cross_attention_kwargs.get("scale", 1.0)
if attention_mask is None:
# if encoder_hidden_states is defined: we are doing cross-attn, so we should use cross-attn mask.
mask = None if encoder_hidden_states is None else encoder_attention_mask
else:
# when attention_mask is defined: we don't even check for encoder_attention_mask.
# this is to maintain compatibility with UnCLIP, which uses 'attention_mask' param for cross-attn masks.
# TODO: UnCLIP should express cross-attn mask via encoder_attention_mask param instead of via attention_mask.
# then we can simplify this whole if/else block to:
# mask = attention_mask if encoder_hidden_states is None else encoder_attention_mask
mask = attention_mask
hidden_states = self.resnets[0](hidden_states, temb, scale=lora_scale)
for attn, resnet in zip(self.attentions, self.resnets[1:]):
# attn
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
attention_mask=mask,
**cross_attention_kwargs,
)
# resnet
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
return hidden_states
class AttnDownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attention_head_dim=1,
output_scale_factor=1.0,
downsample_padding=1,
downsample_type="conv",
):
super().__init__()
resnets = []
attentions = []
self.downsample_type = downsample_type
if attention_head_dim is None:
logger.warn(
f"It is not recommend to pass `attention_head_dim=None`. Defaulting `attention_head_dim` to `in_channels`: {out_channels}."
)
attention_head_dim = out_channels
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
attentions.append(
Attention(
out_channels,
heads=out_channels // attention_head_dim,
dim_head=attention_head_dim,
rescale_output_factor=output_scale_factor,
eps=resnet_eps,
norm_num_groups=resnet_groups,
residual_connection=True,
bias=True,
upcast_softmax=True,
_from_deprecated_attn_block=True,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if downsample_type == "conv":
self.downsamplers = nn.ModuleList(
[
Downsample2D(
out_channels, use_conv=True, out_channels=out_channels, padding=downsample_padding, name="op"
)
]
)
elif downsample_type == "resnet":
self.downsamplers = nn.ModuleList(
[
ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
down=True,
)
]
)
else:
self.downsamplers = None
def forward(self, hidden_states, temb=None, upsample_size=None, cross_attention_kwargs=None):
cross_attention_kwargs = cross_attention_kwargs if cross_attention_kwargs is not None else {}
lora_scale = cross_attention_kwargs.get("scale", 1.0)
output_states = ()
for resnet, attn in zip(self.resnets, self.attentions):
cross_attention_kwargs.update({"scale": lora_scale})
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
hidden_states = attn(hidden_states, **cross_attention_kwargs)
output_states = output_states + (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
if self.downsample_type == "resnet":
hidden_states = downsampler(hidden_states, temb=temb, scale=lora_scale)
else:
hidden_states = downsampler(hidden_states, scale=lora_scale)
output_states += (hidden_states,)
return hidden_states, output_states
class CrossAttnDownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
transformer_layers_per_block: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
num_attention_heads=1,
cross_attention_dim=1280,
output_scale_factor=1.0,
downsample_padding=1,
add_downsample=True,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
attention_type="default",
):
super().__init__()
resnets = []
attentions = []
self.has_cross_attention = True
self.num_attention_heads = num_attention_heads
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
if not dual_cross_attention:
attentions.append(
Transformer2DModel(
num_attention_heads,
out_channels // num_attention_heads,
in_channels=out_channels,
num_layers=transformer_layers_per_block,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
attention_type=attention_type,
)
)
else:
attentions.append(
DualTransformer2DModel(
num_attention_heads,
out_channels // num_attention_heads,
in_channels=out_channels,
num_layers=1,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
Downsample2D(
out_channels, use_conv=True, out_channels=out_channels, padding=downsample_padding, name="op"
)
]
)
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.FloatTensor,
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
additional_residuals=None,
):
output_states = ()
lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0
blocks = list(zip(self.resnets, self.attentions))
for i, (resnet, attn) in enumerate(blocks):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
ckpt_kwargs: Dict[str, Any] = {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet),
hidden_states,
temb,
**ckpt_kwargs,
)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
cross_attention_kwargs=cross_attention_kwargs,
attention_mask=attention_mask,
encoder_attention_mask=encoder_attention_mask,
return_dict=False,
)[0]
else:
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
cross_attention_kwargs=cross_attention_kwargs,
attention_mask=attention_mask,
encoder_attention_mask=encoder_attention_mask,
return_dict=False,
)[0]
# apply additional residuals to the output of the last pair of resnet and attention blocks
if i == len(blocks) - 1 and additional_residuals is not None:
hidden_states = hidden_states + additional_residuals
output_states = output_states + (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states, scale=lora_scale)
output_states = output_states + (hidden_states,)
return hidden_states, output_states
class DownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_downsample=True,
downsample_padding=1,
):
super().__init__()
resnets = []
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.resnets = nn.ModuleList(resnets)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
Downsample2D(
out_channels, use_conv=True, out_channels=out_channels, padding=downsample_padding, name="op"
)
]
)
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, temb=None, scale: float = 1.0):
output_states = ()
for resnet in self.resnets:
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb, use_reentrant=False
)
else:
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb
)
else:
hidden_states = resnet(hidden_states, temb, scale=scale)
output_states = output_states + (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states, scale=scale)
output_states = output_states + (hidden_states,)
return hidden_states, output_states
class DownEncoderBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_downsample=True,
downsample_padding=1,
):
super().__init__()
resnets = []
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=None,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.resnets = nn.ModuleList(resnets)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
Downsample2D(
out_channels, use_conv=True, out_channels=out_channels, padding=downsample_padding, name="op"
)
]
)
else:
self.downsamplers = None
def forward(self, hidden_states, scale: float = 1.0):
for resnet in self.resnets:
hidden_states = resnet(hidden_states, temb=None, scale=scale)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states, scale)
return hidden_states
class AttnDownEncoderBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attention_head_dim=1,
output_scale_factor=1.0,
add_downsample=True,
downsample_padding=1,
):
super().__init__()
resnets = []
attentions = []
if attention_head_dim is None:
logger.warn(
f"It is not recommend to pass `attention_head_dim=None`. Defaulting `attention_head_dim` to `in_channels`: {out_channels}."
)
attention_head_dim = out_channels
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=None,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
attentions.append(
Attention(
out_channels,
heads=out_channels // attention_head_dim,
dim_head=attention_head_dim,
rescale_output_factor=output_scale_factor,
eps=resnet_eps,
norm_num_groups=resnet_groups,
residual_connection=True,
bias=True,
upcast_softmax=True,
_from_deprecated_attn_block=True,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
Downsample2D(
out_channels, use_conv=True, out_channels=out_channels, padding=downsample_padding, name="op"
)
]
)
else:
self.downsamplers = None
def forward(self, hidden_states, scale: float = 1.0):
for resnet, attn in zip(self.resnets, self.attentions):
hidden_states = resnet(hidden_states, temb=None, scale=scale)
cross_attention_kwargs = {"scale": scale}
hidden_states = attn(hidden_states, **cross_attention_kwargs)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states, scale)
return hidden_states
class AttnSkipDownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_pre_norm: bool = True,
attention_head_dim=1,
output_scale_factor=np.sqrt(2.0),
add_downsample=True,
):
super().__init__()
self.attentions = nn.ModuleList([])
self.resnets = nn.ModuleList([])
if attention_head_dim is None:
logger.warn(
f"It is not recommend to pass `attention_head_dim=None`. Defaulting `attention_head_dim` to `in_channels`: {out_channels}."
)
attention_head_dim = out_channels
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
self.resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min(in_channels // 4, 32),
groups_out=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.attentions.append(
Attention(
out_channels,
heads=out_channels // attention_head_dim,
dim_head=attention_head_dim,
rescale_output_factor=output_scale_factor,
eps=resnet_eps,
norm_num_groups=32,
residual_connection=True,
bias=True,
upcast_softmax=True,
_from_deprecated_attn_block=True,
)
)
if add_downsample:
self.resnet_down = ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_in_shortcut=True,
down=True,
kernel="fir",
)
self.downsamplers = nn.ModuleList([FirDownsample2D(out_channels, out_channels=out_channels)])
self.skip_conv = nn.Conv2d(3, out_channels, kernel_size=(1, 1), stride=(1, 1))
else:
self.resnet_down = None
self.downsamplers = None
self.skip_conv = None
def forward(self, hidden_states, temb=None, skip_sample=None, scale: float = 1.0):
output_states = ()
for resnet, attn in zip(self.resnets, self.attentions):
hidden_states = resnet(hidden_states, temb, scale=scale)
cross_attention_kwargs = {"scale": scale}
hidden_states = attn(hidden_states, **cross_attention_kwargs)
output_states += (hidden_states,)
if self.downsamplers is not None:
hidden_states = self.resnet_down(hidden_states, temb, scale=scale)
for downsampler in self.downsamplers:
skip_sample = downsampler(skip_sample)
hidden_states = self.skip_conv(skip_sample) + hidden_states
output_states += (hidden_states,)
return hidden_states, output_states, skip_sample
class SkipDownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_pre_norm: bool = True,
output_scale_factor=np.sqrt(2.0),
add_downsample=True,
downsample_padding=1,
):
super().__init__()
self.resnets = nn.ModuleList([])
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
self.resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min(in_channels // 4, 32),
groups_out=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
if add_downsample:
self.resnet_down = ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_in_shortcut=True,
down=True,
kernel="fir",
)
self.downsamplers = nn.ModuleList([FirDownsample2D(out_channels, out_channels=out_channels)])
self.skip_conv = nn.Conv2d(3, out_channels, kernel_size=(1, 1), stride=(1, 1))
else:
self.resnet_down = None
self.downsamplers = None
self.skip_conv = None
def forward(self, hidden_states, temb=None, skip_sample=None, scale: float = 1.0):
output_states = ()
for resnet in self.resnets:
hidden_states = resnet(hidden_states, temb, scale)
output_states += (hidden_states,)
if self.downsamplers is not None:
hidden_states = self.resnet_down(hidden_states, temb, scale)
for downsampler in self.downsamplers:
skip_sample = downsampler(skip_sample)
hidden_states = self.skip_conv(skip_sample) + hidden_states
output_states += (hidden_states,)
return hidden_states, output_states, skip_sample
class ResnetDownsampleBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_downsample=True,
skip_time_act=False,
):
super().__init__()
resnets = []
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
)
)
self.resnets = nn.ModuleList(resnets)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
down=True,
)
]
)
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, temb=None, scale: float = 1.0):
output_states = ()
for resnet in self.resnets:
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb, use_reentrant=False
)
else:
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb
)
else:
hidden_states = resnet(hidden_states, temb, scale)
output_states = output_states + (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states, temb, scale)
output_states = output_states + (hidden_states,)
return hidden_states, output_states
class SimpleCrossAttnDownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attention_head_dim=1,
cross_attention_dim=1280,
output_scale_factor=1.0,
add_downsample=True,
skip_time_act=False,
only_cross_attention=False,
cross_attention_norm=None,
):
super().__init__()
self.has_cross_attention = True
resnets = []
attentions = []
self.attention_head_dim = attention_head_dim
self.num_heads = out_channels // self.attention_head_dim
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
)
)
processor = (
AttnAddedKVProcessor2_0() if hasattr(F, "scaled_dot_product_attention") else AttnAddedKVProcessor()
)
attentions.append(
Attention(
query_dim=out_channels,
cross_attention_dim=out_channels,
heads=self.num_heads,
dim_head=attention_head_dim,
added_kv_proj_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
bias=True,
upcast_softmax=True,
only_cross_attention=only_cross_attention,
cross_attention_norm=cross_attention_norm,
processor=processor,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
down=True,
)
]
)
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.FloatTensor,
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
):
output_states = ()
cross_attention_kwargs = cross_attention_kwargs if cross_attention_kwargs is not None else {}
lora_scale = cross_attention_kwargs.get("scale", 1.0)
if attention_mask is None:
# if encoder_hidden_states is defined: we are doing cross-attn, so we should use cross-attn mask.
mask = None if encoder_hidden_states is None else encoder_attention_mask
else:
# when attention_mask is defined: we don't even check for encoder_attention_mask.
# this is to maintain compatibility with UnCLIP, which uses 'attention_mask' param for cross-attn masks.
# TODO: UnCLIP should express cross-attn mask via encoder_attention_mask param instead of via attention_mask.
# then we can simplify this whole if/else block to:
# mask = attention_mask if encoder_hidden_states is None else encoder_attention_mask
mask = attention_mask
for resnet, attn in zip(self.resnets, self.attentions):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(resnet), hidden_states, temb)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
attention_mask=mask,
**cross_attention_kwargs,
)
else:
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
attention_mask=mask,
**cross_attention_kwargs,
)
output_states = output_states + (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states, temb, scale=lora_scale)
output_states = output_states + (hidden_states,)
return hidden_states, output_states
class KDownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 4,
resnet_eps: float = 1e-5,
resnet_act_fn: str = "gelu",
resnet_group_size: int = 32,
add_downsample=False,
):
super().__init__()
resnets = []
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
groups = in_channels // resnet_group_size
groups_out = out_channels // resnet_group_size
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
dropout=dropout,
temb_channels=temb_channels,
groups=groups,
groups_out=groups_out,
eps=resnet_eps,
non_linearity=resnet_act_fn,
time_embedding_norm="ada_group",
conv_shortcut_bias=False,
)
)
self.resnets = nn.ModuleList(resnets)
if add_downsample:
# YiYi's comments- might be able to use FirDownsample2D, look into details later
self.downsamplers = nn.ModuleList([KDownsample2D()])
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, temb=None, scale: float = 1.0):
output_states = ()
for resnet in self.resnets:
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb, use_reentrant=False
)
else:
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb
)
else:
hidden_states = resnet(hidden_states, temb, scale)
output_states += (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states)
return hidden_states, output_states
class KCrossAttnDownBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
cross_attention_dim: int,
dropout: float = 0.0,
num_layers: int = 4,
resnet_group_size: int = 32,
add_downsample=True,
attention_head_dim: int = 64,
add_self_attention: bool = False,
resnet_eps: float = 1e-5,
resnet_act_fn: str = "gelu",
):
super().__init__()
resnets = []
attentions = []
self.has_cross_attention = True
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
groups = in_channels // resnet_group_size
groups_out = out_channels // resnet_group_size
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
dropout=dropout,
temb_channels=temb_channels,
groups=groups,
groups_out=groups_out,
eps=resnet_eps,
non_linearity=resnet_act_fn,
time_embedding_norm="ada_group",
conv_shortcut_bias=False,
)
)
attentions.append(
KAttentionBlock(
out_channels,
out_channels // attention_head_dim,
attention_head_dim,
cross_attention_dim=cross_attention_dim,
temb_channels=temb_channels,
attention_bias=True,
add_self_attention=add_self_attention,
cross_attention_norm="layer_norm",
group_size=resnet_group_size,
)
)
self.resnets = nn.ModuleList(resnets)
self.attentions = nn.ModuleList(attentions)
if add_downsample:
self.downsamplers = nn.ModuleList([KDownsample2D()])
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.FloatTensor,
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
):
output_states = ()
lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0
for resnet, attn in zip(self.resnets, self.attentions):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
ckpt_kwargs: Dict[str, Any] = {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet),
hidden_states,
temb,
**ckpt_kwargs,
)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
emb=temb,
attention_mask=attention_mask,
cross_attention_kwargs=cross_attention_kwargs,
encoder_attention_mask=encoder_attention_mask,
)
else:
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
emb=temb,
attention_mask=attention_mask,
cross_attention_kwargs=cross_attention_kwargs,
encoder_attention_mask=encoder_attention_mask,
)
if self.downsamplers is None:
output_states += (None,)
else:
output_states += (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states)
return hidden_states, output_states
class AttnUpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
prev_output_channel: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attention_head_dim=1,
output_scale_factor=1.0,
upsample_type="conv",
):
super().__init__()
resnets = []
attentions = []
self.upsample_type = upsample_type
if attention_head_dim is None:
logger.warn(
f"It is not recommend to pass `attention_head_dim=None`. Defaulting `attention_head_dim` to `in_channels`: {out_channels}."
)
attention_head_dim = out_channels
for i in range(num_layers):
res_skip_channels = in_channels if (i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
attentions.append(
Attention(
out_channels,
heads=out_channels // attention_head_dim,
dim_head=attention_head_dim,
rescale_output_factor=output_scale_factor,
eps=resnet_eps,
norm_num_groups=resnet_groups,
residual_connection=True,
bias=True,
upcast_softmax=True,
_from_deprecated_attn_block=True,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if upsample_type == "conv":
self.upsamplers = nn.ModuleList([Upsample2D(out_channels, use_conv=True, out_channels=out_channels)])
elif upsample_type == "resnet":
self.upsamplers = nn.ModuleList(
[
ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
up=True,
)
]
)
else:
self.upsamplers = None
def forward(self, hidden_states, res_hidden_states_tuple, temb=None, upsample_size=None, scale: float = 1.0):
for resnet, attn in zip(self.resnets, self.attentions):
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat([hidden_states, res_hidden_states], dim=1)
hidden_states = resnet(hidden_states, temb, scale=scale)
cross_attention_kwargs = {"scale": scale}
hidden_states = attn(hidden_states, **cross_attention_kwargs)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
if self.upsample_type == "resnet":
hidden_states = upsampler(hidden_states, temb=temb, scale=scale)
else:
hidden_states = upsampler(hidden_states, scale=scale)
return hidden_states
class CrossAttnUpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
prev_output_channel: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
transformer_layers_per_block: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
num_attention_heads=1,
cross_attention_dim=1280,
output_scale_factor=1.0,
add_upsample=True,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
attention_type="default",
):
super().__init__()
resnets = []
attentions = []
self.has_cross_attention = True
self.num_attention_heads = num_attention_heads
for i in range(num_layers):
res_skip_channels = in_channels if (i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
if not dual_cross_attention:
attentions.append(
Transformer2DModel(
num_attention_heads,
out_channels // num_attention_heads,
in_channels=out_channels,
num_layers=transformer_layers_per_block,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
attention_type=attention_type,
)
)
else:
attentions.append(
DualTransformer2DModel(
num_attention_heads,
out_channels // num_attention_heads,
in_channels=out_channels,
num_layers=1,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if add_upsample:
self.upsamplers = nn.ModuleList([Upsample2D(out_channels, use_conv=True, out_channels=out_channels)])
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.FloatTensor,
res_hidden_states_tuple: Tuple[torch.FloatTensor, ...],
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
upsample_size: Optional[int] = None,
attention_mask: Optional[torch.FloatTensor] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
):
lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0
for resnet, attn in zip(self.resnets, self.attentions):
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat([hidden_states, res_hidden_states], dim=1)
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
ckpt_kwargs: Dict[str, Any] = {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet),
hidden_states,
temb,
**ckpt_kwargs,
)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
cross_attention_kwargs=cross_attention_kwargs,
attention_mask=attention_mask,
encoder_attention_mask=encoder_attention_mask,
return_dict=False,
)[0]
else:
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
cross_attention_kwargs=cross_attention_kwargs,
attention_mask=attention_mask,
encoder_attention_mask=encoder_attention_mask,
return_dict=False,
)[0]
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states, upsample_size, scale=lora_scale)
return hidden_states
class UpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
prev_output_channel: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_upsample=True,
):
super().__init__()
resnets = []
for i in range(num_layers):
res_skip_channels = in_channels if (i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.resnets = nn.ModuleList(resnets)
if add_upsample:
self.upsamplers = nn.ModuleList([Upsample2D(out_channels, use_conv=True, out_channels=out_channels)])
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, res_hidden_states_tuple, temb=None, upsample_size=None, scale: float = 1.0):
for resnet in self.resnets:
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat([hidden_states, res_hidden_states], dim=1)
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb, use_reentrant=False
)
else:
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb
)
else:
hidden_states = resnet(hidden_states, temb, scale=scale)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states, upsample_size, scale=scale)
return hidden_states
class UpDecoderBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default", # default, spatial
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_upsample=True,
temb_channels=None,
):
super().__init__()
resnets = []
for i in range(num_layers):
input_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=input_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.resnets = nn.ModuleList(resnets)
if add_upsample:
self.upsamplers = nn.ModuleList([Upsample2D(out_channels, use_conv=True, out_channels=out_channels)])
else:
self.upsamplers = None
def forward(self, hidden_states, temb=None, scale: float = 1.0):
for resnet in self.resnets:
hidden_states = resnet(hidden_states, temb=temb, scale=scale)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states)
return hidden_states
class AttnUpDecoderBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attention_head_dim=1,
output_scale_factor=1.0,
add_upsample=True,
temb_channels=None,
):
super().__init__()
resnets = []
attentions = []
if attention_head_dim is None:
logger.warn(
f"It is not recommend to pass `attention_head_dim=None`. Defaulting `attention_head_dim` to `out_channels`: {out_channels}."
)
attention_head_dim = out_channels
for i in range(num_layers):
input_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=input_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
attentions.append(
Attention(
out_channels,
heads=out_channels // attention_head_dim,
dim_head=attention_head_dim,
rescale_output_factor=output_scale_factor,
eps=resnet_eps,
norm_num_groups=resnet_groups if resnet_time_scale_shift != "spatial" else None,
spatial_norm_dim=temb_channels if resnet_time_scale_shift == "spatial" else None,
residual_connection=True,
bias=True,
upcast_softmax=True,
_from_deprecated_attn_block=True,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if add_upsample:
self.upsamplers = nn.ModuleList([Upsample2D(out_channels, use_conv=True, out_channels=out_channels)])
else:
self.upsamplers = None
def forward(self, hidden_states, temb=None, scale: float = 1.0):
for resnet, attn in zip(self.resnets, self.attentions):
hidden_states = resnet(hidden_states, temb=temb, scale=scale)
cross_attention_kwargs = {"scale": scale}
hidden_states = attn(hidden_states, temb=temb, **cross_attention_kwargs)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states, scale=scale)
return hidden_states
class AttnSkipUpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
prev_output_channel: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_pre_norm: bool = True,
attention_head_dim=1,
output_scale_factor=np.sqrt(2.0),
add_upsample=True,
):
super().__init__()
self.attentions = nn.ModuleList([])
self.resnets = nn.ModuleList([])
for i in range(num_layers):
res_skip_channels = in_channels if (i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
self.resnets.append(
ResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min(resnet_in_channels + res_skip_channels // 4, 32),
groups_out=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
if attention_head_dim is None:
logger.warn(
f"It is not recommend to pass `attention_head_dim=None`. Defaulting `attention_head_dim` to `out_channels`: {out_channels}."
)
attention_head_dim = out_channels
self.attentions.append(
Attention(
out_channels,
heads=out_channels // attention_head_dim,
dim_head=attention_head_dim,
rescale_output_factor=output_scale_factor,
eps=resnet_eps,
norm_num_groups=32,
residual_connection=True,
bias=True,
upcast_softmax=True,
_from_deprecated_attn_block=True,
)
)
self.upsampler = FirUpsample2D(in_channels, out_channels=out_channels)
if add_upsample:
self.resnet_up = ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min(out_channels // 4, 32),
groups_out=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_in_shortcut=True,
up=True,
kernel="fir",
)
self.skip_conv = nn.Conv2d(out_channels, 3, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
self.skip_norm = torch.nn.GroupNorm(
num_groups=min(out_channels // 4, 32), num_channels=out_channels, eps=resnet_eps, affine=True
)
self.act = nn.SiLU()
else:
self.resnet_up = None
self.skip_conv = None
self.skip_norm = None
self.act = None
def forward(self, hidden_states, res_hidden_states_tuple, temb=None, skip_sample=None, scale: float = 1.0):
for resnet in self.resnets:
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat([hidden_states, res_hidden_states], dim=1)
hidden_states = resnet(hidden_states, temb, scale=scale)
cross_attention_kwargs = {"scale": scale}
hidden_states = self.attentions[0](hidden_states, **cross_attention_kwargs)
if skip_sample is not None:
skip_sample = self.upsampler(skip_sample)
else:
skip_sample = 0
if self.resnet_up is not None:
skip_sample_states = self.skip_norm(hidden_states)
skip_sample_states = self.act(skip_sample_states)
skip_sample_states = self.skip_conv(skip_sample_states)
skip_sample = skip_sample + skip_sample_states
hidden_states = self.resnet_up(hidden_states, temb, scale=scale)
return hidden_states, skip_sample
class SkipUpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
prev_output_channel: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_pre_norm: bool = True,
output_scale_factor=np.sqrt(2.0),
add_upsample=True,
upsample_padding=1,
):
super().__init__()
self.resnets = nn.ModuleList([])
for i in range(num_layers):
res_skip_channels = in_channels if (i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
self.resnets.append(
ResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min((resnet_in_channels + res_skip_channels) // 4, 32),
groups_out=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
)
)
self.upsampler = FirUpsample2D(in_channels, out_channels=out_channels)
if add_upsample:
self.resnet_up = ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=min(out_channels // 4, 32),
groups_out=min(out_channels // 4, 32),
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_in_shortcut=True,
up=True,
kernel="fir",
)
self.skip_conv = nn.Conv2d(out_channels, 3, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
self.skip_norm = torch.nn.GroupNorm(
num_groups=min(out_channels // 4, 32), num_channels=out_channels, eps=resnet_eps, affine=True
)
self.act = nn.SiLU()
else:
self.resnet_up = None
self.skip_conv = None
self.skip_norm = None
self.act = None
def forward(self, hidden_states, res_hidden_states_tuple, temb=None, skip_sample=None, scale: float = 1.0):
for resnet in self.resnets:
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat([hidden_states, res_hidden_states], dim=1)
hidden_states = resnet(hidden_states, temb, scale=scale)
if skip_sample is not None:
skip_sample = self.upsampler(skip_sample)
else:
skip_sample = 0
if self.resnet_up is not None:
skip_sample_states = self.skip_norm(hidden_states)
skip_sample_states = self.act(skip_sample_states)
skip_sample_states = self.skip_conv(skip_sample_states)
skip_sample = skip_sample + skip_sample_states
hidden_states = self.resnet_up(hidden_states, temb, scale=scale)
return hidden_states, skip_sample
class ResnetUpsampleBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
prev_output_channel: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_upsample=True,
skip_time_act=False,
):
super().__init__()
resnets = []
for i in range(num_layers):
res_skip_channels = in_channels if (i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
)
)
self.resnets = nn.ModuleList(resnets)
if add_upsample:
self.upsamplers = nn.ModuleList(
[
ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
up=True,
)
]
)
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, res_hidden_states_tuple, temb=None, upsample_size=None, scale: float = 1.0):
for resnet in self.resnets:
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat([hidden_states, res_hidden_states], dim=1)
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb, use_reentrant=False
)
else:
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb
)
else:
hidden_states = resnet(hidden_states, temb, scale=scale)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states, temb, scale=scale)
return hidden_states
class SimpleCrossAttnUpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
prev_output_channel: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attention_head_dim=1,
cross_attention_dim=1280,
output_scale_factor=1.0,
add_upsample=True,
skip_time_act=False,
only_cross_attention=False,
cross_attention_norm=None,
):
super().__init__()
resnets = []
attentions = []
self.has_cross_attention = True
self.attention_head_dim = attention_head_dim
self.num_heads = out_channels // self.attention_head_dim
for i in range(num_layers):
res_skip_channels = in_channels if (i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
resnets.append(
ResnetBlock2D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
)
)
processor = (
AttnAddedKVProcessor2_0() if hasattr(F, "scaled_dot_product_attention") else AttnAddedKVProcessor()
)
attentions.append(
Attention(
query_dim=out_channels,
cross_attention_dim=out_channels,
heads=self.num_heads,
dim_head=self.attention_head_dim,
added_kv_proj_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
bias=True,
upcast_softmax=True,
only_cross_attention=only_cross_attention,
cross_attention_norm=cross_attention_norm,
processor=processor,
)
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
if add_upsample:
self.upsamplers = nn.ModuleList(
[
ResnetBlock2D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
skip_time_act=skip_time_act,
up=True,
)
]
)
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.FloatTensor,
res_hidden_states_tuple: Tuple[torch.FloatTensor, ...],
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
upsample_size: Optional[int] = None,
attention_mask: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
):
cross_attention_kwargs = cross_attention_kwargs if cross_attention_kwargs is not None else {}
lora_scale = cross_attention_kwargs.get("scale", 1.0)
if attention_mask is None:
# if encoder_hidden_states is defined: we are doing cross-attn, so we should use cross-attn mask.
mask = None if encoder_hidden_states is None else encoder_attention_mask
else:
# when attention_mask is defined: we don't even check for encoder_attention_mask.
# this is to maintain compatibility with UnCLIP, which uses 'attention_mask' param for cross-attn masks.
# TODO: UnCLIP should express cross-attn mask via encoder_attention_mask param instead of via attention_mask.
# then we can simplify this whole if/else block to:
# mask = attention_mask if encoder_hidden_states is None else encoder_attention_mask
mask = attention_mask
for resnet, attn in zip(self.resnets, self.attentions):
# resnet
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat([hidden_states, res_hidden_states], dim=1)
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(resnet), hidden_states, temb)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
attention_mask=mask,
**cross_attention_kwargs,
)
else:
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
attention_mask=mask,
**cross_attention_kwargs,
)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states, temb, scale=lora_scale)
return hidden_states
class KUpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 5,
resnet_eps: float = 1e-5,
resnet_act_fn: str = "gelu",
resnet_group_size: Optional[int] = 32,
add_upsample=True,
):
super().__init__()
resnets = []
k_in_channels = 2 * out_channels
k_out_channels = in_channels
num_layers = num_layers - 1
for i in range(num_layers):
in_channels = k_in_channels if i == 0 else out_channels
groups = in_channels // resnet_group_size
groups_out = out_channels // resnet_group_size
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=k_out_channels if (i == num_layers - 1) else out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=groups,
groups_out=groups_out,
dropout=dropout,
non_linearity=resnet_act_fn,
time_embedding_norm="ada_group",
conv_shortcut_bias=False,
)
)
self.resnets = nn.ModuleList(resnets)
if add_upsample:
self.upsamplers = nn.ModuleList([KUpsample2D()])
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, res_hidden_states_tuple, temb=None, upsample_size=None, scale: float = 1.0):
res_hidden_states_tuple = res_hidden_states_tuple[-1]
if res_hidden_states_tuple is not None:
hidden_states = torch.cat([hidden_states, res_hidden_states_tuple], dim=1)
for resnet in self.resnets:
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if is_torch_version(">=", "1.11.0"):
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb, use_reentrant=False
)
else:
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet), hidden_states, temb
)
else:
hidden_states = resnet(hidden_states, temb, scale=scale)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states)
return hidden_states
class KCrossAttnUpBlock2D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 4,
resnet_eps: float = 1e-5,
resnet_act_fn: str = "gelu",
resnet_group_size: int = 32,
attention_head_dim=1, # attention dim_head
cross_attention_dim: int = 768,
add_upsample: bool = True,
upcast_attention: bool = False,
):
super().__init__()
resnets = []
attentions = []
is_first_block = in_channels == out_channels == temb_channels
is_middle_block = in_channels != out_channels
add_self_attention = True if is_first_block else False
self.has_cross_attention = True
self.attention_head_dim = attention_head_dim
# in_channels, and out_channels for the block (k-unet)
k_in_channels = out_channels if is_first_block else 2 * out_channels
k_out_channels = in_channels
num_layers = num_layers - 1
for i in range(num_layers):
in_channels = k_in_channels if i == 0 else out_channels
groups = in_channels // resnet_group_size
groups_out = out_channels // resnet_group_size
if is_middle_block and (i == num_layers - 1):
conv_2d_out_channels = k_out_channels
else:
conv_2d_out_channels = None
resnets.append(
ResnetBlock2D(
in_channels=in_channels,
out_channels=out_channels,
conv_2d_out_channels=conv_2d_out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=groups,
groups_out=groups_out,
dropout=dropout,
non_linearity=resnet_act_fn,
time_embedding_norm="ada_group",
conv_shortcut_bias=False,
)
)
attentions.append(
KAttentionBlock(
k_out_channels if (i == num_layers - 1) else out_channels,
k_out_channels // attention_head_dim
if (i == num_layers - 1)
else out_channels // attention_head_dim,
attention_head_dim,
cross_attention_dim=cross_attention_dim,
temb_channels=temb_channels,
attention_bias=True,
add_self_attention=add_self_attention,
cross_attention_norm="layer_norm",
upcast_attention=upcast_attention,
)
)
self.resnets = nn.ModuleList(resnets)
self.attentions = nn.ModuleList(attentions)
if add_upsample:
self.upsamplers = nn.ModuleList([KUpsample2D()])
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.FloatTensor,
res_hidden_states_tuple: Tuple[torch.FloatTensor, ...],
temb: Optional[torch.FloatTensor] = None,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
upsample_size: Optional[int] = None,
attention_mask: Optional[torch.FloatTensor] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
):
res_hidden_states_tuple = res_hidden_states_tuple[-1]
if res_hidden_states_tuple is not None:
hidden_states = torch.cat([hidden_states, res_hidden_states_tuple], dim=1)
lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0
for resnet, attn in zip(self.resnets, self.attentions):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
ckpt_kwargs: Dict[str, Any] = {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(resnet),
hidden_states,
temb,
**ckpt_kwargs,
)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
emb=temb,
attention_mask=attention_mask,
cross_attention_kwargs=cross_attention_kwargs,
encoder_attention_mask=encoder_attention_mask,
)
else:
hidden_states = resnet(hidden_states, temb, scale=lora_scale)
hidden_states = attn(
hidden_states,
encoder_hidden_states=encoder_hidden_states,
emb=temb,
attention_mask=attention_mask,
cross_attention_kwargs=cross_attention_kwargs,
encoder_attention_mask=encoder_attention_mask,
)
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states)
return hidden_states
# can potentially later be renamed to `No-feed-forward` attention
class KAttentionBlock(nn.Module):
r"""
A basic Transformer block.
Parameters:
dim (`int`): The number of channels in the input and output.
num_attention_heads (`int`): The number of heads to use for multi-head attention.
attention_head_dim (`int`): The number of channels in each head.
dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
cross_attention_dim (`int`, *optional*): The size of the encoder_hidden_states vector for cross attention.
activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to be used in feed-forward.
num_embeds_ada_norm (:
obj: `int`, *optional*): The number of diffusion steps used during training. See `Transformer2DModel`.
attention_bias (:
obj: `bool`, *optional*, defaults to `False`): Configure if the attentions should contain a bias parameter.
"""
def __init__(
self,
dim: int,
num_attention_heads: int,
attention_head_dim: int,
dropout: float = 0.0,
cross_attention_dim: Optional[int] = None,
attention_bias: bool = False,
upcast_attention: bool = False,
temb_channels: int = 768, # for ada_group_norm
add_self_attention: bool = False,
cross_attention_norm: Optional[str] = None,
group_size: int = 32,
):
super().__init__()
self.add_self_attention = add_self_attention
# 1. Self-Attn
if add_self_attention:
self.norm1 = AdaGroupNorm(temb_channels, dim, max(1, dim // group_size))
self.attn1 = Attention(
query_dim=dim,
heads=num_attention_heads,
dim_head=attention_head_dim,
dropout=dropout,
bias=attention_bias,
cross_attention_dim=None,
cross_attention_norm=None,
)
# 2. Cross-Attn
self.norm2 = AdaGroupNorm(temb_channels, dim, max(1, dim // group_size))
self.attn2 = Attention(
query_dim=dim,
cross_attention_dim=cross_attention_dim,
heads=num_attention_heads,
dim_head=attention_head_dim,
dropout=dropout,
bias=attention_bias,
upcast_attention=upcast_attention,
cross_attention_norm=cross_attention_norm,
)
def _to_3d(self, hidden_states, height, weight):
return hidden_states.permute(0, 2, 3, 1).reshape(hidden_states.shape[0], height * weight, -1)
def _to_4d(self, hidden_states, height, weight):
return hidden_states.permute(0, 2, 1).reshape(hidden_states.shape[0], -1, height, weight)
def forward(
self,
hidden_states: torch.FloatTensor,
encoder_hidden_states: Optional[torch.FloatTensor] = None,
# TODO: mark emb as non-optional (self.norm2 requires it).
# requires assessing impact of change to positional param interface.
emb: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.FloatTensor] = None,
cross_attention_kwargs: Optional[Dict[str, Any]] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
):
cross_attention_kwargs = cross_attention_kwargs if cross_attention_kwargs is not None else {}
# 1. Self-Attention
if self.add_self_attention:
norm_hidden_states = self.norm1(hidden_states, emb)
height, weight = norm_hidden_states.shape[2:]
norm_hidden_states = self._to_3d(norm_hidden_states, height, weight)
attn_output = self.attn1(
norm_hidden_states,
encoder_hidden_states=None,
attention_mask=attention_mask,
**cross_attention_kwargs,
)
attn_output = self._to_4d(attn_output, height, weight)
hidden_states = attn_output + hidden_states
# 2. Cross-Attention/None
norm_hidden_states = self.norm2(hidden_states, emb)
height, weight = norm_hidden_states.shape[2:]
norm_hidden_states = self._to_3d(norm_hidden_states, height, weight)
attn_output = self.attn2(
norm_hidden_states,
encoder_hidden_states=encoder_hidden_states,
attention_mask=attention_mask if encoder_hidden_states is None else encoder_attention_mask,
**cross_attention_kwargs,
)
attn_output = self._to_4d(attn_output, height, weight)
hidden_states = attn_output + hidden_states
return hidden_states
| diffusers-main | src/diffusers/models/unet_2d_blocks.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Optional, Tuple, Union
import flax
import flax.linen as nn
import jax
import jax.numpy as jnp
from flax.core.frozen_dict import FrozenDict
from ..configuration_utils import ConfigMixin, flax_register_to_config
from ..utils import BaseOutput
from .embeddings_flax import FlaxTimestepEmbedding, FlaxTimesteps
from .modeling_flax_utils import FlaxModelMixin
from .unet_2d_blocks_flax import (
FlaxCrossAttnDownBlock2D,
FlaxDownBlock2D,
FlaxUNetMidBlock2DCrossAttn,
)
@flax.struct.dataclass
class FlaxControlNetOutput(BaseOutput):
"""
The output of [`FlaxControlNetModel`].
Args:
down_block_res_samples (`jnp.ndarray`):
mid_block_res_sample (`jnp.ndarray`):
"""
down_block_res_samples: jnp.ndarray
mid_block_res_sample: jnp.ndarray
class FlaxControlNetConditioningEmbedding(nn.Module):
conditioning_embedding_channels: int
block_out_channels: Tuple[int] = (16, 32, 96, 256)
dtype: jnp.dtype = jnp.float32
def setup(self):
self.conv_in = nn.Conv(
self.block_out_channels[0],
kernel_size=(3, 3),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
blocks = []
for i in range(len(self.block_out_channels) - 1):
channel_in = self.block_out_channels[i]
channel_out = self.block_out_channels[i + 1]
conv1 = nn.Conv(
channel_in,
kernel_size=(3, 3),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
blocks.append(conv1)
conv2 = nn.Conv(
channel_out,
kernel_size=(3, 3),
strides=(2, 2),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
blocks.append(conv2)
self.blocks = blocks
self.conv_out = nn.Conv(
self.conditioning_embedding_channels,
kernel_size=(3, 3),
padding=((1, 1), (1, 1)),
kernel_init=nn.initializers.zeros_init(),
bias_init=nn.initializers.zeros_init(),
dtype=self.dtype,
)
def __call__(self, conditioning):
embedding = self.conv_in(conditioning)
embedding = nn.silu(embedding)
for block in self.blocks:
embedding = block(embedding)
embedding = nn.silu(embedding)
embedding = self.conv_out(embedding)
return embedding
@flax_register_to_config
class FlaxControlNetModel(nn.Module, FlaxModelMixin, ConfigMixin):
r"""
A ControlNet model.
This model inherits from [`FlaxModelMixin`]. Check the superclass documentation for it’s generic methods
implemented for all models (such as downloading or saving).
This model is also a Flax Linen [`flax.linen.Module`](https://flax.readthedocs.io/en/latest/flax.linen.html#module)
subclass. Use it as a regular Flax Linen module and refer to the Flax documentation for all matters related to its
general usage and behavior.
Inherent JAX features such as the following are supported:
- [Just-In-Time (JIT) compilation](https://jax.readthedocs.io/en/latest/jax.html#just-in-time-compilation-jit)
- [Automatic Differentiation](https://jax.readthedocs.io/en/latest/jax.html#automatic-differentiation)
- [Vectorization](https://jax.readthedocs.io/en/latest/jax.html#vectorization-vmap)
- [Parallelization](https://jax.readthedocs.io/en/latest/jax.html#parallelization-pmap)
Parameters:
sample_size (`int`, *optional*):
The size of the input sample.
in_channels (`int`, *optional*, defaults to 4):
The number of channels in the input sample.
down_block_types (`Tuple[str]`, *optional*, defaults to `("FlaxCrossAttnDownBlock2D", "FlaxCrossAttnDownBlock2D", "FlaxCrossAttnDownBlock2D", "FlaxDownBlock2D")`):
The tuple of downsample blocks to use.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(320, 640, 1280, 1280)`):
The tuple of output channels for each block.
layers_per_block (`int`, *optional*, defaults to 2):
The number of layers per block.
attention_head_dim (`int` or `Tuple[int]`, *optional*, defaults to 8):
The dimension of the attention heads.
num_attention_heads (`int` or `Tuple[int]`, *optional*):
The number of attention heads.
cross_attention_dim (`int`, *optional*, defaults to 768):
The dimension of the cross attention features.
dropout (`float`, *optional*, defaults to 0):
Dropout probability for down, up and bottleneck blocks.
flip_sin_to_cos (`bool`, *optional*, defaults to `True`):
Whether to flip the sin to cos in the time embedding.
freq_shift (`int`, *optional*, defaults to 0): The frequency shift to apply to the time embedding.
controlnet_conditioning_channel_order (`str`, *optional*, defaults to `rgb`):
The channel order of conditional image. Will convert to `rgb` if it's `bgr`.
conditioning_embedding_out_channels (`tuple`, *optional*, defaults to `(16, 32, 96, 256)`):
The tuple of output channel for each block in the `conditioning_embedding` layer.
"""
sample_size: int = 32
in_channels: int = 4
down_block_types: Tuple[str] = (
"CrossAttnDownBlock2D",
"CrossAttnDownBlock2D",
"CrossAttnDownBlock2D",
"DownBlock2D",
)
only_cross_attention: Union[bool, Tuple[bool]] = False
block_out_channels: Tuple[int] = (320, 640, 1280, 1280)
layers_per_block: int = 2
attention_head_dim: Union[int, Tuple[int]] = 8
num_attention_heads: Optional[Union[int, Tuple[int]]] = None
cross_attention_dim: int = 1280
dropout: float = 0.0
use_linear_projection: bool = False
dtype: jnp.dtype = jnp.float32
flip_sin_to_cos: bool = True
freq_shift: int = 0
controlnet_conditioning_channel_order: str = "rgb"
conditioning_embedding_out_channels: Tuple[int] = (16, 32, 96, 256)
def init_weights(self, rng: jax.random.KeyArray) -> FrozenDict:
# init input tensors
sample_shape = (1, self.in_channels, self.sample_size, self.sample_size)
sample = jnp.zeros(sample_shape, dtype=jnp.float32)
timesteps = jnp.ones((1,), dtype=jnp.int32)
encoder_hidden_states = jnp.zeros((1, 1, self.cross_attention_dim), dtype=jnp.float32)
controlnet_cond_shape = (1, 3, self.sample_size * 8, self.sample_size * 8)
controlnet_cond = jnp.zeros(controlnet_cond_shape, dtype=jnp.float32)
params_rng, dropout_rng = jax.random.split(rng)
rngs = {"params": params_rng, "dropout": dropout_rng}
return self.init(rngs, sample, timesteps, encoder_hidden_states, controlnet_cond)["params"]
def setup(self):
block_out_channels = self.block_out_channels
time_embed_dim = block_out_channels[0] * 4
# If `num_attention_heads` is not defined (which is the case for most models)
# it will default to `attention_head_dim`. This looks weird upon first reading it and it is.
# The reason for this behavior is to correct for incorrectly named variables that were introduced
# when this library was created. The incorrect naming was only discovered much later in https://github.com/huggingface/diffusers/issues/2011#issuecomment-1547958131
# Changing `attention_head_dim` to `num_attention_heads` for 40,000+ configurations is too backwards breaking
# which is why we correct for the naming here.
num_attention_heads = self.num_attention_heads or self.attention_head_dim
# input
self.conv_in = nn.Conv(
block_out_channels[0],
kernel_size=(3, 3),
strides=(1, 1),
padding=((1, 1), (1, 1)),
dtype=self.dtype,
)
# time
self.time_proj = FlaxTimesteps(
block_out_channels[0], flip_sin_to_cos=self.flip_sin_to_cos, freq_shift=self.config.freq_shift
)
self.time_embedding = FlaxTimestepEmbedding(time_embed_dim, dtype=self.dtype)
self.controlnet_cond_embedding = FlaxControlNetConditioningEmbedding(
conditioning_embedding_channels=block_out_channels[0],
block_out_channels=self.conditioning_embedding_out_channels,
)
only_cross_attention = self.only_cross_attention
if isinstance(only_cross_attention, bool):
only_cross_attention = (only_cross_attention,) * len(self.down_block_types)
if isinstance(num_attention_heads, int):
num_attention_heads = (num_attention_heads,) * len(self.down_block_types)
# down
down_blocks = []
controlnet_down_blocks = []
output_channel = block_out_channels[0]
controlnet_block = nn.Conv(
output_channel,
kernel_size=(1, 1),
padding="VALID",
kernel_init=nn.initializers.zeros_init(),
bias_init=nn.initializers.zeros_init(),
dtype=self.dtype,
)
controlnet_down_blocks.append(controlnet_block)
for i, down_block_type in enumerate(self.down_block_types):
input_channel = output_channel
output_channel = block_out_channels[i]
is_final_block = i == len(block_out_channels) - 1
if down_block_type == "CrossAttnDownBlock2D":
down_block = FlaxCrossAttnDownBlock2D(
in_channels=input_channel,
out_channels=output_channel,
dropout=self.dropout,
num_layers=self.layers_per_block,
num_attention_heads=num_attention_heads[i],
add_downsample=not is_final_block,
use_linear_projection=self.use_linear_projection,
only_cross_attention=only_cross_attention[i],
dtype=self.dtype,
)
else:
down_block = FlaxDownBlock2D(
in_channels=input_channel,
out_channels=output_channel,
dropout=self.dropout,
num_layers=self.layers_per_block,
add_downsample=not is_final_block,
dtype=self.dtype,
)
down_blocks.append(down_block)
for _ in range(self.layers_per_block):
controlnet_block = nn.Conv(
output_channel,
kernel_size=(1, 1),
padding="VALID",
kernel_init=nn.initializers.zeros_init(),
bias_init=nn.initializers.zeros_init(),
dtype=self.dtype,
)
controlnet_down_blocks.append(controlnet_block)
if not is_final_block:
controlnet_block = nn.Conv(
output_channel,
kernel_size=(1, 1),
padding="VALID",
kernel_init=nn.initializers.zeros_init(),
bias_init=nn.initializers.zeros_init(),
dtype=self.dtype,
)
controlnet_down_blocks.append(controlnet_block)
self.down_blocks = down_blocks
self.controlnet_down_blocks = controlnet_down_blocks
# mid
mid_block_channel = block_out_channels[-1]
self.mid_block = FlaxUNetMidBlock2DCrossAttn(
in_channels=mid_block_channel,
dropout=self.dropout,
num_attention_heads=num_attention_heads[-1],
use_linear_projection=self.use_linear_projection,
dtype=self.dtype,
)
self.controlnet_mid_block = nn.Conv(
mid_block_channel,
kernel_size=(1, 1),
padding="VALID",
kernel_init=nn.initializers.zeros_init(),
bias_init=nn.initializers.zeros_init(),
dtype=self.dtype,
)
def __call__(
self,
sample,
timesteps,
encoder_hidden_states,
controlnet_cond,
conditioning_scale: float = 1.0,
return_dict: bool = True,
train: bool = False,
) -> Union[FlaxControlNetOutput, Tuple]:
r"""
Args:
sample (`jnp.ndarray`): (batch, channel, height, width) noisy inputs tensor
timestep (`jnp.ndarray` or `float` or `int`): timesteps
encoder_hidden_states (`jnp.ndarray`): (batch_size, sequence_length, hidden_size) encoder hidden states
controlnet_cond (`jnp.ndarray`): (batch, channel, height, width) the conditional input tensor
conditioning_scale: (`float`) the scale factor for controlnet outputs
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`models.unet_2d_condition_flax.FlaxUNet2DConditionOutput`] instead of a
plain tuple.
train (`bool`, *optional*, defaults to `False`):
Use deterministic functions and disable dropout when not training.
Returns:
[`~models.unet_2d_condition_flax.FlaxUNet2DConditionOutput`] or `tuple`:
[`~models.unet_2d_condition_flax.FlaxUNet2DConditionOutput`] if `return_dict` is True, otherwise a `tuple`.
When returning a tuple, the first element is the sample tensor.
"""
channel_order = self.controlnet_conditioning_channel_order
if channel_order == "bgr":
controlnet_cond = jnp.flip(controlnet_cond, axis=1)
# 1. time
if not isinstance(timesteps, jnp.ndarray):
timesteps = jnp.array([timesteps], dtype=jnp.int32)
elif isinstance(timesteps, jnp.ndarray) and len(timesteps.shape) == 0:
timesteps = timesteps.astype(dtype=jnp.float32)
timesteps = jnp.expand_dims(timesteps, 0)
t_emb = self.time_proj(timesteps)
t_emb = self.time_embedding(t_emb)
# 2. pre-process
sample = jnp.transpose(sample, (0, 2, 3, 1))
sample = self.conv_in(sample)
controlnet_cond = jnp.transpose(controlnet_cond, (0, 2, 3, 1))
controlnet_cond = self.controlnet_cond_embedding(controlnet_cond)
sample += controlnet_cond
# 3. down
down_block_res_samples = (sample,)
for down_block in self.down_blocks:
if isinstance(down_block, FlaxCrossAttnDownBlock2D):
sample, res_samples = down_block(sample, t_emb, encoder_hidden_states, deterministic=not train)
else:
sample, res_samples = down_block(sample, t_emb, deterministic=not train)
down_block_res_samples += res_samples
# 4. mid
sample = self.mid_block(sample, t_emb, encoder_hidden_states, deterministic=not train)
# 5. contronet blocks
controlnet_down_block_res_samples = ()
for down_block_res_sample, controlnet_block in zip(down_block_res_samples, self.controlnet_down_blocks):
down_block_res_sample = controlnet_block(down_block_res_sample)
controlnet_down_block_res_samples += (down_block_res_sample,)
down_block_res_samples = controlnet_down_block_res_samples
mid_block_res_sample = self.controlnet_mid_block(sample)
# 6. scaling
down_block_res_samples = [sample * conditioning_scale for sample in down_block_res_samples]
mid_block_res_sample *= conditioning_scale
if not return_dict:
return (down_block_res_samples, mid_block_res_sample)
return FlaxControlNetOutput(
down_block_res_samples=down_block_res_samples, mid_block_res_sample=mid_block_res_sample
)
| diffusers-main | src/diffusers/models/controlnet_flax.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import platform
from argparse import ArgumentParser
import huggingface_hub
from .. import __version__ as version
from ..utils import is_accelerate_available, is_torch_available, is_transformers_available, is_xformers_available
from . import BaseDiffusersCLICommand
def info_command_factory(_):
return EnvironmentCommand()
class EnvironmentCommand(BaseDiffusersCLICommand):
@staticmethod
def register_subcommand(parser: ArgumentParser):
download_parser = parser.add_parser("env")
download_parser.set_defaults(func=info_command_factory)
def run(self):
hub_version = huggingface_hub.__version__
pt_version = "not installed"
pt_cuda_available = "NA"
if is_torch_available():
import torch
pt_version = torch.__version__
pt_cuda_available = torch.cuda.is_available()
transformers_version = "not installed"
if is_transformers_available():
import transformers
transformers_version = transformers.__version__
accelerate_version = "not installed"
if is_accelerate_available():
import accelerate
accelerate_version = accelerate.__version__
xformers_version = "not installed"
if is_xformers_available():
import xformers
xformers_version = xformers.__version__
info = {
"`diffusers` version": version,
"Platform": platform.platform(),
"Python version": platform.python_version(),
"PyTorch version (GPU?)": f"{pt_version} ({pt_cuda_available})",
"Huggingface_hub version": hub_version,
"Transformers version": transformers_version,
"Accelerate version": accelerate_version,
"xFormers version": xformers_version,
"Using GPU in script?": "<fill in>",
"Using distributed or parallel set-up in script?": "<fill in>",
}
print("\nCopy-and-paste the text below in your GitHub issue and FILL OUT the two last points.\n")
print(self.format_dict(info))
return info
@staticmethod
def format_dict(d):
return "\n".join([f"- {prop}: {val}" for prop, val in d.items()]) + "\n"
| diffusers-main | src/diffusers/commands/env.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from abc import ABC, abstractmethod
from argparse import ArgumentParser
class BaseDiffusersCLICommand(ABC):
@staticmethod
@abstractmethod
def register_subcommand(parser: ArgumentParser):
raise NotImplementedError()
@abstractmethod
def run(self):
raise NotImplementedError()
| diffusers-main | src/diffusers/commands/__init__.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Usage example:
diffusers-cli fp16_safetensors --ckpt_id=openai/shap-e --fp16 --use_safetensors
"""
import glob
import json
from argparse import ArgumentParser, Namespace
from importlib import import_module
import huggingface_hub
import torch
from huggingface_hub import hf_hub_download
from packaging import version
from ..utils import logging
from . import BaseDiffusersCLICommand
def conversion_command_factory(args: Namespace):
return FP16SafetensorsCommand(
args.ckpt_id,
args.fp16,
args.use_safetensors,
args.use_auth_token,
)
class FP16SafetensorsCommand(BaseDiffusersCLICommand):
@staticmethod
def register_subcommand(parser: ArgumentParser):
conversion_parser = parser.add_parser("fp16_safetensors")
conversion_parser.add_argument(
"--ckpt_id",
type=str,
help="Repo id of the checkpoints on which to run the conversion. Example: 'openai/shap-e'.",
)
conversion_parser.add_argument(
"--fp16", action="store_true", help="If serializing the variables in FP16 precision."
)
conversion_parser.add_argument(
"--use_safetensors", action="store_true", help="If serializing in the safetensors format."
)
conversion_parser.add_argument(
"--use_auth_token",
action="store_true",
help="When working with checkpoints having private visibility. When used `huggingface-cli login` needs to be run beforehand.",
)
conversion_parser.set_defaults(func=conversion_command_factory)
def __init__(self, ckpt_id: str, fp16: bool, use_safetensors: bool, use_auth_token: bool):
self.logger = logging.get_logger("diffusers-cli/fp16_safetensors")
self.ckpt_id = ckpt_id
self.local_ckpt_dir = f"/tmp/{ckpt_id}"
self.fp16 = fp16
self.use_safetensors = use_safetensors
if not self.use_safetensors and not self.fp16:
raise NotImplementedError(
"When `use_safetensors` and `fp16` both are False, then this command is of no use."
)
self.use_auth_token = use_auth_token
def run(self):
if version.parse(huggingface_hub.__version__) < version.parse("0.9.0"):
raise ImportError(
"The huggingface_hub version must be >= 0.9.0 to use this command. Please update your huggingface_hub"
" installation."
)
else:
from huggingface_hub import create_commit
from huggingface_hub._commit_api import CommitOperationAdd
model_index = hf_hub_download(repo_id=self.ckpt_id, filename="model_index.json", token=self.use_auth_token)
with open(model_index, "r") as f:
pipeline_class_name = json.load(f)["_class_name"]
pipeline_class = getattr(import_module("diffusers"), pipeline_class_name)
self.logger.info(f"Pipeline class imported: {pipeline_class_name}.")
# Load the appropriate pipeline. We could have use `DiffusionPipeline`
# here, but just to avoid any rough edge cases.
pipeline = pipeline_class.from_pretrained(
self.ckpt_id, torch_dtype=torch.float16 if self.fp16 else torch.float32, use_auth_token=self.use_auth_token
)
pipeline.save_pretrained(
self.local_ckpt_dir,
safe_serialization=True if self.use_safetensors else False,
variant="fp16" if self.fp16 else None,
)
self.logger.info(f"Pipeline locally saved to {self.local_ckpt_dir}.")
# Fetch all the paths.
if self.fp16:
modified_paths = glob.glob(f"{self.local_ckpt_dir}/*/*.fp16.*")
elif self.use_safetensors:
modified_paths = glob.glob(f"{self.local_ckpt_dir}/*/*.safetensors")
# Prepare for the PR.
commit_message = f"Serialize variables with FP16: {self.fp16} and safetensors: {self.use_safetensors}."
operations = []
for path in modified_paths:
operations.append(CommitOperationAdd(path_in_repo="/".join(path.split("/")[4:]), path_or_fileobj=path))
# Open the PR.
commit_description = (
"Variables converted by the [`diffusers`' `fp16_safetensors`"
" CLI](https://github.com/huggingface/diffusers/blob/main/src/diffusers/commands/fp16_safetensors.py)."
)
hub_pr_url = create_commit(
repo_id=self.ckpt_id,
operations=operations,
commit_message=commit_message,
commit_description=commit_description,
repo_type="model",
create_pr=True,
).pr_url
self.logger.info(f"PR created here: {hub_pr_url}.")
| diffusers-main | src/diffusers/commands/fp16_safetensors.py |
#!/usr/bin/env python
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from argparse import ArgumentParser
from .env import EnvironmentCommand
from .fp16_safetensors import FP16SafetensorsCommand
def main():
parser = ArgumentParser("Diffusers CLI tool", usage="diffusers-cli <command> [<args>]")
commands_parser = parser.add_subparsers(help="diffusers-cli command helpers")
# Register commands
EnvironmentCommand.register_subcommand(commands_parser)
FP16SafetensorsCommand.register_subcommand(commands_parser)
# Let's go
args = parser.parse_args()
if not hasattr(args, "func"):
parser.print_help()
exit(1)
# Run
service = args.func(args)
service.run()
if __name__ == "__main__":
main()
| diffusers-main | src/diffusers/commands/diffusers_cli.py |
# Copyright 2023 NVIDIA and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import flax
import jax.numpy as jnp
from jax import random
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from .scheduling_utils_flax import FlaxSchedulerMixin
@flax.struct.dataclass
class KarrasVeSchedulerState:
# setable values
num_inference_steps: Optional[int] = None
timesteps: Optional[jnp.ndarray] = None
schedule: Optional[jnp.ndarray] = None # sigma(t_i)
@classmethod
def create(cls):
return cls()
@dataclass
class FlaxKarrasVeOutput(BaseOutput):
"""
Output class for the scheduler's step function output.
Args:
prev_sample (`jnp.ndarray` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
derivative (`jnp.ndarray` of shape `(batch_size, num_channels, height, width)` for images):
Derivative of predicted original image sample (x_0).
state (`KarrasVeSchedulerState`): the `FlaxKarrasVeScheduler` state data class.
"""
prev_sample: jnp.ndarray
derivative: jnp.ndarray
state: KarrasVeSchedulerState
class FlaxKarrasVeScheduler(FlaxSchedulerMixin, ConfigMixin):
"""
Stochastic sampling from Karras et al. [1] tailored to the Variance-Expanding (VE) models [2]. Use Algorithm 2 and
the VE column of Table 1 from [1] for reference.
[1] Karras, Tero, et al. "Elucidating the Design Space of Diffusion-Based Generative Models."
https://arxiv.org/abs/2206.00364 [2] Song, Yang, et al. "Score-based generative modeling through stochastic
differential equations." https://arxiv.org/abs/2011.13456
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details on the parameters, see the original paper's Appendix E.: "Elucidating the Design Space of
Diffusion-Based Generative Models." https://arxiv.org/abs/2206.00364. The grid search values used to find the
optimal {s_noise, s_churn, s_min, s_max} for a specific model are described in Table 5 of the paper.
Args:
sigma_min (`float`): minimum noise magnitude
sigma_max (`float`): maximum noise magnitude
s_noise (`float`): the amount of additional noise to counteract loss of detail during sampling.
A reasonable range is [1.000, 1.011].
s_churn (`float`): the parameter controlling the overall amount of stochasticity.
A reasonable range is [0, 100].
s_min (`float`): the start value of the sigma range where we add noise (enable stochasticity).
A reasonable range is [0, 10].
s_max (`float`): the end value of the sigma range where we add noise.
A reasonable range is [0.2, 80].
"""
@property
def has_state(self):
return True
@register_to_config
def __init__(
self,
sigma_min: float = 0.02,
sigma_max: float = 100,
s_noise: float = 1.007,
s_churn: float = 80,
s_min: float = 0.05,
s_max: float = 50,
):
pass
def create_state(self):
return KarrasVeSchedulerState.create()
def set_timesteps(
self, state: KarrasVeSchedulerState, num_inference_steps: int, shape: Tuple = ()
) -> KarrasVeSchedulerState:
"""
Sets the continuous timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
state (`KarrasVeSchedulerState`):
the `FlaxKarrasVeScheduler` state data class.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
"""
timesteps = jnp.arange(0, num_inference_steps)[::-1].copy()
schedule = [
(
self.config.sigma_max**2
* (self.config.sigma_min**2 / self.config.sigma_max**2) ** (i / (num_inference_steps - 1))
)
for i in timesteps
]
return state.replace(
num_inference_steps=num_inference_steps,
schedule=jnp.array(schedule, dtype=jnp.float32),
timesteps=timesteps,
)
def add_noise_to_input(
self,
state: KarrasVeSchedulerState,
sample: jnp.ndarray,
sigma: float,
key: random.KeyArray,
) -> Tuple[jnp.ndarray, float]:
"""
Explicit Langevin-like "churn" step of adding noise to the sample according to a factor gamma_i ≥ 0 to reach a
higher noise level sigma_hat = sigma_i + gamma_i*sigma_i.
TODO Args:
"""
if self.config.s_min <= sigma <= self.config.s_max:
gamma = min(self.config.s_churn / state.num_inference_steps, 2**0.5 - 1)
else:
gamma = 0
# sample eps ~ N(0, S_noise^2 * I)
key = random.split(key, num=1)
eps = self.config.s_noise * random.normal(key=key, shape=sample.shape)
sigma_hat = sigma + gamma * sigma
sample_hat = sample + ((sigma_hat**2 - sigma**2) ** 0.5 * eps)
return sample_hat, sigma_hat
def step(
self,
state: KarrasVeSchedulerState,
model_output: jnp.ndarray,
sigma_hat: float,
sigma_prev: float,
sample_hat: jnp.ndarray,
return_dict: bool = True,
) -> Union[FlaxKarrasVeOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
state (`KarrasVeSchedulerState`): the `FlaxKarrasVeScheduler` state data class.
model_output (`torch.FloatTensor` or `np.ndarray`): direct output from learned diffusion model.
sigma_hat (`float`): TODO
sigma_prev (`float`): TODO
sample_hat (`torch.FloatTensor` or `np.ndarray`): TODO
return_dict (`bool`): option for returning tuple rather than FlaxKarrasVeOutput class
Returns:
[`~schedulers.scheduling_karras_ve_flax.FlaxKarrasVeOutput`] or `tuple`: Updated sample in the diffusion
chain and derivative. [`~schedulers.scheduling_karras_ve_flax.FlaxKarrasVeOutput`] if `return_dict` is
True, otherwise a `tuple`. When returning a tuple, the first element is the sample tensor.
"""
pred_original_sample = sample_hat + sigma_hat * model_output
derivative = (sample_hat - pred_original_sample) / sigma_hat
sample_prev = sample_hat + (sigma_prev - sigma_hat) * derivative
if not return_dict:
return (sample_prev, derivative, state)
return FlaxKarrasVeOutput(prev_sample=sample_prev, derivative=derivative, state=state)
def step_correct(
self,
state: KarrasVeSchedulerState,
model_output: jnp.ndarray,
sigma_hat: float,
sigma_prev: float,
sample_hat: jnp.ndarray,
sample_prev: jnp.ndarray,
derivative: jnp.ndarray,
return_dict: bool = True,
) -> Union[FlaxKarrasVeOutput, Tuple]:
"""
Correct the predicted sample based on the output model_output of the network. TODO complete description
Args:
state (`KarrasVeSchedulerState`): the `FlaxKarrasVeScheduler` state data class.
model_output (`torch.FloatTensor` or `np.ndarray`): direct output from learned diffusion model.
sigma_hat (`float`): TODO
sigma_prev (`float`): TODO
sample_hat (`torch.FloatTensor` or `np.ndarray`): TODO
sample_prev (`torch.FloatTensor` or `np.ndarray`): TODO
derivative (`torch.FloatTensor` or `np.ndarray`): TODO
return_dict (`bool`): option for returning tuple rather than FlaxKarrasVeOutput class
Returns:
prev_sample (TODO): updated sample in the diffusion chain. derivative (TODO): TODO
"""
pred_original_sample = sample_prev + sigma_prev * model_output
derivative_corr = (sample_prev - pred_original_sample) / sigma_prev
sample_prev = sample_hat + (sigma_prev - sigma_hat) * (0.5 * derivative + 0.5 * derivative_corr)
if not return_dict:
return (sample_prev, derivative, state)
return FlaxKarrasVeOutput(prev_sample=sample_prev, derivative=derivative, state=state)
def add_noise(self, state: KarrasVeSchedulerState, original_samples, noise, timesteps):
raise NotImplementedError()
| diffusers-main | src/diffusers/schedulers/scheduling_karras_ve_flax.py |
# Copyright 2023 Katherine Crowson and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput, logging
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput with DDPM->EulerDiscrete
class EulerDiscreteSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class EulerDiscreteScheduler(SchedulerMixin, ConfigMixin):
"""
Euler scheduler.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
interpolation_type(`str`, defaults to `"linear"`, *optional*):
The interpolation type to compute intermediate sigmas for the scheduler denoising steps. Should be on of
`"linear"` or `"log_linear"`.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
prediction_type: str = "epsilon",
interpolation_type: str = "linear",
use_karras_sigmas: Optional[bool] = False,
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
sigmas = np.concatenate([sigmas[::-1], [0.0]]).astype(np.float32)
self.sigmas = torch.from_numpy(sigmas)
# setable values
self.num_inference_steps = None
timesteps = np.linspace(0, num_train_timesteps - 1, num_train_timesteps, dtype=float)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps)
self.is_scale_input_called = False
self.use_karras_sigmas = use_karras_sigmas
self._step_index = None
@property
def init_noise_sigma(self):
# standard deviation of the initial noise distribution
if self.config.timestep_spacing in ["linspace", "trailing"]:
return self.sigmas.max()
return (self.sigmas.max() ** 2 + 1) ** 0.5
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self, sample: torch.FloatTensor, timestep: Union[float, torch.FloatTensor]
) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep. Scales the denoising model input by `(sigma**2 + 1) ** 0.5` to match the Euler algorithm.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
sample = sample / ((sigma**2 + 1) ** 0.5)
self.is_scale_input_called = True
return sample
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps, dtype=np.float32)[
::-1
].copy()
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.float32)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(self.config.num_train_timesteps, 0, -step_ratio)).round().copy().astype(np.float32)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
log_sigmas = np.log(sigmas)
if self.config.interpolation_type == "linear":
sigmas = np.interp(timesteps, np.arange(0, len(sigmas)), sigmas)
elif self.config.interpolation_type == "log_linear":
sigmas = torch.linspace(np.log(sigmas[-1]), np.log(sigmas[0]), num_inference_steps + 1).exp()
else:
raise ValueError(
f"{self.config.interpolation_type} is not implemented. Please specify interpolation_type to either"
" 'linear' or 'log_linear'"
)
if self.use_karras_sigmas:
sigmas = self._convert_to_karras(in_sigmas=sigmas, num_inference_steps=self.num_inference_steps)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas])
sigmas = np.concatenate([sigmas, [0.0]]).astype(np.float32)
self.sigmas = torch.from_numpy(sigmas).to(device=device)
self.timesteps = torch.from_numpy(timesteps).to(device=device)
self._step_index = None
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# Copied from https://github.com/crowsonkb/k-diffusion/blob/686dbad0f39640ea25c8a8c6a6e56bb40eacefa2/k_diffusion/sampling.py#L17
def _convert_to_karras(self, in_sigmas: torch.FloatTensor, num_inference_steps) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
def step(
self,
model_output: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
sample: torch.FloatTensor,
s_churn: float = 0.0,
s_tmin: float = 0.0,
s_tmax: float = float("inf"),
s_noise: float = 1.0,
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[EulerDiscreteSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
s_churn (`float`):
s_tmin (`float`):
s_tmax (`float`):
s_noise (`float`, defaults to 1.0):
Scaling factor for noise added to the sample.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_euler_discrete.EulerDiscreteSchedulerOutput`] or
tuple.
Returns:
[`~schedulers.scheduling_euler_discrete.EulerDiscreteSchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_euler_discrete.EulerDiscreteSchedulerOutput`] is
returned, otherwise a tuple is returned where the first element is the sample tensor.
"""
if (
isinstance(timestep, int)
or isinstance(timestep, torch.IntTensor)
or isinstance(timestep, torch.LongTensor)
):
raise ValueError(
(
"Passing integer indices (e.g. from `enumerate(timesteps)`) as timesteps to"
" `EulerDiscreteScheduler.step()` is not supported. Make sure to pass"
" one of the `scheduler.timesteps` as a timestep."
),
)
if not self.is_scale_input_called:
logger.warning(
"The `scale_model_input` function should be called before `step` to ensure correct denoising. "
"See `StableDiffusionPipeline` for a usage example."
)
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
gamma = min(s_churn / (len(self.sigmas) - 1), 2**0.5 - 1) if s_tmin <= sigma <= s_tmax else 0.0
noise = randn_tensor(
model_output.shape, dtype=model_output.dtype, device=model_output.device, generator=generator
)
eps = noise * s_noise
sigma_hat = sigma * (gamma + 1)
if gamma > 0:
sample = sample + eps * (sigma_hat**2 - sigma**2) ** 0.5
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
# NOTE: "original_sample" should not be an expected prediction_type but is left in for
# backwards compatibility
if self.config.prediction_type == "original_sample" or self.config.prediction_type == "sample":
pred_original_sample = model_output
elif self.config.prediction_type == "epsilon":
pred_original_sample = sample - sigma_hat * model_output
elif self.config.prediction_type == "v_prediction":
# * c_out + input * c_skip
pred_original_sample = model_output * (-sigma / (sigma**2 + 1) ** 0.5) + (sample / (sigma**2 + 1))
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
# 2. Convert to an ODE derivative
derivative = (sample - pred_original_sample) / sigma_hat
dt = self.sigmas[self.step_index + 1] - sigma_hat
prev_sample = sample + derivative * dt
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return EulerDiscreteSchedulerOutput(prev_sample=prev_sample, pred_original_sample=pred_original_sample)
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [(schedule_timesteps == t).nonzero().item() for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_euler_discrete.py |
# Copyright 2023 UC Berkeley Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
@dataclass
class DDPMSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DDPMScheduler(SchedulerMixin, ConfigMixin):
"""
`DDPMScheduler` explores the connections between denoising score matching and Langevin dynamics sampling.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
variance_type (`str`, defaults to `"fixed_small"`):
Clip the variance when adding noise to the denoised sample. Choose from `fixed_small`, `fixed_small_log`,
`fixed_large`, `fixed_large_log`, `learned` or `learned_range`.
clip_sample (`bool`, defaults to `True`):
Clip the predicted sample for numerical stability.
clip_sample_range (`float`, defaults to 1.0):
The maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
thresholding (`bool`, defaults to `False`):
Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
as Stable Diffusion.
dynamic_thresholding_ratio (`float`, defaults to 0.995):
The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
sample_max_value (`float`, defaults to 1.0):
The threshold value for dynamic thresholding. Valid only when `thresholding=True`.
timestep_spacing (`str`, defaults to `"leading"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
variance_type: str = "fixed_small",
clip_sample: bool = True,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
clip_sample_range: float = 1.0,
sample_max_value: float = 1.0,
timestep_spacing: str = "leading",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
elif beta_schedule == "sigmoid":
# GeoDiff sigmoid schedule
betas = torch.linspace(-6, 6, num_train_timesteps)
self.betas = torch.sigmoid(betas) * (beta_end - beta_start) + beta_start
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
self.one = torch.tensor(1.0)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# setable values
self.custom_timesteps = False
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy())
self.variance_type = variance_type
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def set_timesteps(
self,
num_inference_steps: Optional[int] = None,
device: Union[str, torch.device] = None,
timesteps: Optional[List[int]] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model. If used,
`timesteps` must be `None`.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
timesteps (`List[int]`, *optional*):
Custom timesteps used to support arbitrary spacing between timesteps. If `None`, then the default
timestep spacing strategy of equal spacing between timesteps is used. If `timesteps` is passed,
`num_inference_steps` must be `None`.
"""
if num_inference_steps is not None and timesteps is not None:
raise ValueError("Can only pass one of `num_inference_steps` or `custom_timesteps`.")
if timesteps is not None:
for i in range(1, len(timesteps)):
if timesteps[i] >= timesteps[i - 1]:
raise ValueError("`custom_timesteps` must be in descending order.")
if timesteps[0] >= self.config.num_train_timesteps:
raise ValueError(
f"`timesteps` must start before `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps}."
)
timesteps = np.array(timesteps, dtype=np.int64)
self.custom_timesteps = True
else:
if num_inference_steps > self.config.num_train_timesteps:
raise ValueError(
f"`num_inference_steps`: {num_inference_steps} cannot be larger than `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps} as the unet model trained with this scheduler can only handle"
f" maximal {self.config.num_train_timesteps} timesteps."
)
self.num_inference_steps = num_inference_steps
self.custom_timesteps = False
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps)
.round()[::-1]
.copy()
.astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.round(np.arange(self.config.num_train_timesteps, 0, -step_ratio)).astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
self.timesteps = torch.from_numpy(timesteps).to(device)
def _get_variance(self, t, predicted_variance=None, variance_type=None):
prev_t = self.previous_timestep(t)
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_t] if prev_t >= 0 else self.one
current_beta_t = 1 - alpha_prod_t / alpha_prod_t_prev
# For t > 0, compute predicted variance βt (see formula (6) and (7) from https://arxiv.org/pdf/2006.11239.pdf)
# and sample from it to get previous sample
# x_{t-1} ~ N(pred_prev_sample, variance) == add variance to pred_sample
variance = (1 - alpha_prod_t_prev) / (1 - alpha_prod_t) * current_beta_t
# we always take the log of variance, so clamp it to ensure it's not 0
variance = torch.clamp(variance, min=1e-20)
if variance_type is None:
variance_type = self.config.variance_type
# hacks - were probably added for training stability
if variance_type == "fixed_small":
variance = variance
# for rl-diffuser https://arxiv.org/abs/2205.09991
elif variance_type == "fixed_small_log":
variance = torch.log(variance)
variance = torch.exp(0.5 * variance)
elif variance_type == "fixed_large":
variance = current_beta_t
elif variance_type == "fixed_large_log":
# Glide max_log
variance = torch.log(current_beta_t)
elif variance_type == "learned":
return predicted_variance
elif variance_type == "learned_range":
min_log = torch.log(variance)
max_log = torch.log(current_beta_t)
frac = (predicted_variance + 1) / 2
variance = frac * max_log + (1 - frac) * min_log
return variance
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
generator=None,
return_dict: bool = True,
) -> Union[DDPMSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_ddpm.DDPMSchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_ddpm.DDPMSchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_ddpm.DDPMSchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
t = timestep
prev_t = self.previous_timestep(t)
if model_output.shape[1] == sample.shape[1] * 2 and self.variance_type in ["learned", "learned_range"]:
model_output, predicted_variance = torch.split(model_output, sample.shape[1], dim=1)
else:
predicted_variance = None
# 1. compute alphas, betas
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_t] if prev_t >= 0 else self.one
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
current_alpha_t = alpha_prod_t / alpha_prod_t_prev
current_beta_t = 1 - current_alpha_t
# 2. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample` or"
" `v_prediction` for the DDPMScheduler."
)
# 3. Clip or threshold "predicted x_0"
if self.config.thresholding:
pred_original_sample = self._threshold_sample(pred_original_sample)
elif self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
# 4. Compute coefficients for pred_original_sample x_0 and current sample x_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_original_sample_coeff = (alpha_prod_t_prev ** (0.5) * current_beta_t) / beta_prod_t
current_sample_coeff = current_alpha_t ** (0.5) * beta_prod_t_prev / beta_prod_t
# 5. Compute predicted previous sample µ_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_prev_sample = pred_original_sample_coeff * pred_original_sample + current_sample_coeff * sample
# 6. Add noise
variance = 0
if t > 0:
device = model_output.device
variance_noise = randn_tensor(
model_output.shape, generator=generator, device=device, dtype=model_output.dtype
)
if self.variance_type == "fixed_small_log":
variance = self._get_variance(t, predicted_variance=predicted_variance) * variance_noise
elif self.variance_type == "learned_range":
variance = self._get_variance(t, predicted_variance=predicted_variance)
variance = torch.exp(0.5 * variance) * variance_noise
else:
variance = (self._get_variance(t, predicted_variance=predicted_variance) ** 0.5) * variance_noise
pred_prev_sample = pred_prev_sample + variance
if not return_dict:
return (pred_prev_sample,)
return DDPMSchedulerOutput(prev_sample=pred_prev_sample, pred_original_sample=pred_original_sample)
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def get_velocity(
self, sample: torch.FloatTensor, noise: torch.FloatTensor, timesteps: torch.IntTensor
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as sample
alphas_cumprod = self.alphas_cumprod.to(device=sample.device, dtype=sample.dtype)
timesteps = timesteps.to(sample.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(sample.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(sample.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
velocity = sqrt_alpha_prod * noise - sqrt_one_minus_alpha_prod * sample
return velocity
def __len__(self):
return self.config.num_train_timesteps
def previous_timestep(self, timestep):
if self.custom_timesteps:
index = (self.timesteps == timestep).nonzero(as_tuple=True)[0][0]
if index == self.timesteps.shape[0] - 1:
prev_t = torch.tensor(-1)
else:
prev_t = self.timesteps[index + 1]
else:
num_inference_steps = (
self.num_inference_steps if self.num_inference_steps else self.config.num_train_timesteps
)
prev_t = timestep - self.config.num_train_timesteps // num_inference_steps
return prev_t
| diffusers-main | src/diffusers/schedulers/scheduling_ddpm.py |
# Copyright 2023 Katherine Crowson, The HuggingFace Team and hlky. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from collections import defaultdict
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class HeunDiscreteScheduler(SchedulerMixin, ConfigMixin):
"""
Scheduler with Heun steps for discrete beta schedules.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
clip_sample (`bool`, defaults to `True`):
Clip the predicted sample for numerical stability.
clip_sample_range (`float`, defaults to 1.0):
The maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 2
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.00085, # sensible defaults
beta_end: float = 0.012,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
prediction_type: str = "epsilon",
use_karras_sigmas: Optional[bool] = False,
clip_sample: Optional[bool] = False,
clip_sample_range: float = 1.0,
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps, alpha_transform_type="cosine")
elif beta_schedule == "exp":
self.betas = betas_for_alpha_bar(num_train_timesteps, alpha_transform_type="exp")
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# set all values
self.set_timesteps(num_train_timesteps, None, num_train_timesteps)
self.use_karras_sigmas = use_karras_sigmas
self._step_index = None
def index_for_timestep(self, timestep, schedule_timesteps=None):
if schedule_timesteps is None:
schedule_timesteps = self.timesteps
indices = (schedule_timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(self._index_counter) == 0:
pos = 1 if len(indices) > 1 else 0
else:
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
pos = self._index_counter[timestep_int]
return indices[pos].item()
@property
def init_noise_sigma(self):
# standard deviation of the initial noise distribution
if self.config.timestep_spacing in ["linspace", "trailing"]:
return self.sigmas.max()
return (self.sigmas.max() ** 2 + 1) ** 0.5
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self,
sample: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
sample = sample / ((sigma**2 + 1) ** 0.5)
return sample
def set_timesteps(
self,
num_inference_steps: int,
device: Union[str, torch.device] = None,
num_train_timesteps: Optional[int] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
num_train_timesteps = num_train_timesteps or self.config.num_train_timesteps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = np.linspace(0, num_train_timesteps - 1, num_inference_steps, dtype=np.float32)[::-1].copy()
elif self.config.timestep_spacing == "leading":
step_ratio = num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.float32)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(num_train_timesteps, 0, -step_ratio)).round().copy().astype(np.float32)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
log_sigmas = np.log(sigmas)
sigmas = np.interp(timesteps, np.arange(0, len(sigmas)), sigmas)
if self.config.use_karras_sigmas:
sigmas = self._convert_to_karras(in_sigmas=sigmas, num_inference_steps=self.num_inference_steps)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas])
sigmas = np.concatenate([sigmas, [0.0]]).astype(np.float32)
sigmas = torch.from_numpy(sigmas).to(device=device)
self.sigmas = torch.cat([sigmas[:1], sigmas[1:-1].repeat_interleave(2), sigmas[-1:]])
timesteps = torch.from_numpy(timesteps)
timesteps = torch.cat([timesteps[:1], timesteps[1:].repeat_interleave(2)])
self.timesteps = timesteps.to(device=device)
# empty dt and derivative
self.prev_derivative = None
self.dt = None
self._step_index = None
# (YiYi Notes: keep this for now since we are keeping add_noise function which use index_for_timestep)
# for exp beta schedules, such as the one for `pipeline_shap_e.py`
# we need an index counter
self._index_counter = defaultdict(int)
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._sigma_to_t
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._convert_to_karras
def _convert_to_karras(self, in_sigmas: torch.FloatTensor, num_inference_steps) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
@property
def state_in_first_order(self):
return self.dt is None
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
def step(
self,
model_output: Union[torch.FloatTensor, np.ndarray],
timestep: Union[float, torch.FloatTensor],
sample: Union[torch.FloatTensor, np.ndarray],
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.step_index is None:
self._init_step_index(timestep)
# (YiYi notes: keep this for now since we are keeping the add_noise method)
# advance index counter by 1
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
self._index_counter[timestep_int] += 1
if self.state_in_first_order:
sigma = self.sigmas[self.step_index]
sigma_next = self.sigmas[self.step_index + 1]
else:
# 2nd order / Heun's method
sigma = self.sigmas[self.step_index - 1]
sigma_next = self.sigmas[self.step_index]
# currently only gamma=0 is supported. This usually works best anyways.
# We can support gamma in the future but then need to scale the timestep before
# passing it to the model which requires a change in API
gamma = 0
sigma_hat = sigma * (gamma + 1) # Note: sigma_hat == sigma for now
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
if self.config.prediction_type == "epsilon":
sigma_input = sigma_hat if self.state_in_first_order else sigma_next
pred_original_sample = sample - sigma_input * model_output
elif self.config.prediction_type == "v_prediction":
sigma_input = sigma_hat if self.state_in_first_order else sigma_next
pred_original_sample = model_output * (-sigma_input / (sigma_input**2 + 1) ** 0.5) + (
sample / (sigma_input**2 + 1)
)
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
if self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
if self.state_in_first_order:
# 2. Convert to an ODE derivative for 1st order
derivative = (sample - pred_original_sample) / sigma_hat
# 3. delta timestep
dt = sigma_next - sigma_hat
# store for 2nd order step
self.prev_derivative = derivative
self.dt = dt
self.sample = sample
else:
# 2. 2nd order / Heun's method
derivative = (sample - pred_original_sample) / sigma_next
derivative = (self.prev_derivative + derivative) / 2
# 3. take prev timestep & sample
dt = self.dt
sample = self.sample
# free dt and derivative
# Note, this puts the scheduler in "first order mode"
self.prev_derivative = None
self.dt = None
self.sample = None
prev_sample = sample + derivative * dt
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [self.index_for_timestep(t, schedule_timesteps) for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_heun_discrete.py |
# Copyright 2023 Katherine Crowson, The HuggingFace Team and hlky. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from collections import defaultdict
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class KDPM2DiscreteScheduler(SchedulerMixin, ConfigMixin):
"""
KDPM2DiscreteScheduler is inspired by the DPMSolver2 and Algorithm 2 from the [Elucidating the Design Space of
Diffusion-Based Generative Models](https://huggingface.co/papers/2206.00364) paper.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.00085):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.012):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 2
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.00085, # sensible defaults
beta_end: float = 0.012,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
prediction_type: str = "epsilon",
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# set all values
self.set_timesteps(num_train_timesteps, None, num_train_timesteps)
self._step_index = None
# Copied from diffusers.schedulers.scheduling_heun_discrete.HeunDiscreteScheduler.index_for_timestep
def index_for_timestep(self, timestep, schedule_timesteps=None):
if schedule_timesteps is None:
schedule_timesteps = self.timesteps
indices = (schedule_timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(self._index_counter) == 0:
pos = 1 if len(indices) > 1 else 0
else:
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
pos = self._index_counter[timestep_int]
return indices[pos].item()
@property
def init_noise_sigma(self):
# standard deviation of the initial noise distribution
if self.config.timestep_spacing in ["linspace", "trailing"]:
return self.sigmas.max()
return (self.sigmas.max() ** 2 + 1) ** 0.5
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self,
sample: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
if self.step_index is None:
self._init_step_index(timestep)
if self.state_in_first_order:
sigma = self.sigmas[self.step_index]
else:
sigma = self.sigmas_interpol[self.step_index]
sample = sample / ((sigma**2 + 1) ** 0.5)
return sample
def set_timesteps(
self,
num_inference_steps: int,
device: Union[str, torch.device] = None,
num_train_timesteps: Optional[int] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
num_train_timesteps = num_train_timesteps or self.config.num_train_timesteps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = np.linspace(0, num_train_timesteps - 1, num_inference_steps, dtype=np.float32)[::-1].copy()
elif self.config.timestep_spacing == "leading":
step_ratio = num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.float32)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(num_train_timesteps, 0, -step_ratio)).round().copy().astype(np.float32)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
self.log_sigmas = torch.from_numpy(np.log(sigmas)).to(device)
sigmas = np.interp(timesteps, np.arange(0, len(sigmas)), sigmas)
sigmas = np.concatenate([sigmas, [0.0]]).astype(np.float32)
sigmas = torch.from_numpy(sigmas).to(device=device)
# interpolate sigmas
sigmas_interpol = sigmas.log().lerp(sigmas.roll(1).log(), 0.5).exp()
self.sigmas = torch.cat([sigmas[:1], sigmas[1:].repeat_interleave(2), sigmas[-1:]])
self.sigmas_interpol = torch.cat(
[sigmas_interpol[:1], sigmas_interpol[1:].repeat_interleave(2), sigmas_interpol[-1:]]
)
timesteps = torch.from_numpy(timesteps).to(device)
# interpolate timesteps
timesteps_interpol = self.sigma_to_t(sigmas_interpol).to(device, dtype=timesteps.dtype)
interleaved_timesteps = torch.stack((timesteps_interpol[1:-1, None], timesteps[1:, None]), dim=-1).flatten()
self.timesteps = torch.cat([timesteps[:1], interleaved_timesteps])
self.sample = None
# for exp beta schedules, such as the one for `pipeline_shap_e.py`
# we need an index counter
self._index_counter = defaultdict(int)
self._step_index = None
def sigma_to_t(self, sigma):
# get log sigma
log_sigma = sigma.log()
# get distribution
dists = log_sigma - self.log_sigmas[:, None]
# get sigmas range
low_idx = dists.ge(0).cumsum(dim=0).argmax(dim=0).clamp(max=self.log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = self.log_sigmas[low_idx]
high = self.log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = w.clamp(0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.view(sigma.shape)
return t
@property
def state_in_first_order(self):
return self.sample is None
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
def step(
self,
model_output: Union[torch.FloatTensor, np.ndarray],
timestep: Union[float, torch.FloatTensor],
sample: Union[torch.FloatTensor, np.ndarray],
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.step_index is None:
self._init_step_index(timestep)
# advance index counter by 1
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
self._index_counter[timestep_int] += 1
if self.state_in_first_order:
sigma = self.sigmas[self.step_index]
sigma_interpol = self.sigmas_interpol[self.step_index + 1]
sigma_next = self.sigmas[self.step_index + 1]
else:
# 2nd order / KDPM2's method
sigma = self.sigmas[self.step_index - 1]
sigma_interpol = self.sigmas_interpol[self.step_index]
sigma_next = self.sigmas[self.step_index]
# currently only gamma=0 is supported. This usually works best anyways.
# We can support gamma in the future but then need to scale the timestep before
# passing it to the model which requires a change in API
gamma = 0
sigma_hat = sigma * (gamma + 1) # Note: sigma_hat == sigma for now
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
if self.config.prediction_type == "epsilon":
sigma_input = sigma_hat if self.state_in_first_order else sigma_interpol
pred_original_sample = sample - sigma_input * model_output
elif self.config.prediction_type == "v_prediction":
sigma_input = sigma_hat if self.state_in_first_order else sigma_interpol
pred_original_sample = model_output * (-sigma_input / (sigma_input**2 + 1) ** 0.5) + (
sample / (sigma_input**2 + 1)
)
elif self.config.prediction_type == "sample":
raise NotImplementedError("prediction_type not implemented yet: sample")
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
if self.state_in_first_order:
# 2. Convert to an ODE derivative for 1st order
derivative = (sample - pred_original_sample) / sigma_hat
# 3. delta timestep
dt = sigma_interpol - sigma_hat
# store for 2nd order step
self.sample = sample
else:
# DPM-Solver-2
# 2. Convert to an ODE derivative for 2nd order
derivative = (sample - pred_original_sample) / sigma_interpol
# 3. delta timestep
dt = sigma_next - sigma_hat
sample = self.sample
self.sample = None
# upon completion increase step index by one
self._step_index += 1
prev_sample = sample + derivative * dt
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
# Copied from diffusers.schedulers.scheduling_heun_discrete.HeunDiscreteScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [self.index_for_timestep(t, schedule_timesteps) for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_k_dpm_2_discrete.py |
# Copyright 2023 Zhejiang University Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import flax
import jax
import jax.numpy as jnp
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils_flax import (
CommonSchedulerState,
FlaxKarrasDiffusionSchedulers,
FlaxSchedulerMixin,
FlaxSchedulerOutput,
add_noise_common,
)
@flax.struct.dataclass
class PNDMSchedulerState:
common: CommonSchedulerState
final_alpha_cumprod: jnp.ndarray
# setable values
init_noise_sigma: jnp.ndarray
timesteps: jnp.ndarray
num_inference_steps: Optional[int] = None
prk_timesteps: Optional[jnp.ndarray] = None
plms_timesteps: Optional[jnp.ndarray] = None
# running values
cur_model_output: Optional[jnp.ndarray] = None
counter: Optional[jnp.int32] = None
cur_sample: Optional[jnp.ndarray] = None
ets: Optional[jnp.ndarray] = None
@classmethod
def create(
cls,
common: CommonSchedulerState,
final_alpha_cumprod: jnp.ndarray,
init_noise_sigma: jnp.ndarray,
timesteps: jnp.ndarray,
):
return cls(
common=common,
final_alpha_cumprod=final_alpha_cumprod,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
)
@dataclass
class FlaxPNDMSchedulerOutput(FlaxSchedulerOutput):
state: PNDMSchedulerState
class FlaxPNDMScheduler(FlaxSchedulerMixin, ConfigMixin):
"""
Pseudo numerical methods for diffusion models (PNDM) proposes using more advanced ODE integration techniques,
namely Runge-Kutta method and a linear multi-step method.
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details, see the original paper: https://arxiv.org/abs/2202.09778
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
beta_start (`float`): the starting `beta` value of inference.
beta_end (`float`): the final `beta` value.
beta_schedule (`str`):
the beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`jnp.ndarray`, optional):
option to pass an array of betas directly to the constructor to bypass `beta_start`, `beta_end` etc.
skip_prk_steps (`bool`):
allows the scheduler to skip the Runge-Kutta steps that are defined in the original paper as being required
before plms steps; defaults to `False`.
set_alpha_to_one (`bool`, default `False`):
each diffusion step uses the value of alphas product at that step and at the previous one. For the final
step there is no previous alpha. When this option is `True` the previous alpha product is fixed to `1`,
otherwise it uses the value of alpha at step 0.
steps_offset (`int`, default `0`):
an offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False`, to make the last step use step 0 for the previous alpha product, as done in
stable diffusion.
prediction_type (`str`, default `epsilon`, optional):
prediction type of the scheduler function, one of `epsilon` (predicting the noise of the diffusion
process), `sample` (directly predicting the noisy sample`) or `v_prediction` (see section 2.4
https://imagen.research.google/video/paper.pdf)
dtype (`jnp.dtype`, *optional*, defaults to `jnp.float32`):
the `dtype` used for params and computation.
"""
_compatibles = [e.name for e in FlaxKarrasDiffusionSchedulers]
dtype: jnp.dtype
pndm_order: int
@property
def has_state(self):
return True
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[jnp.ndarray] = None,
skip_prk_steps: bool = False,
set_alpha_to_one: bool = False,
steps_offset: int = 0,
prediction_type: str = "epsilon",
dtype: jnp.dtype = jnp.float32,
):
self.dtype = dtype
# For now we only support F-PNDM, i.e. the runge-kutta method
# For more information on the algorithm please take a look at the paper: https://arxiv.org/pdf/2202.09778.pdf
# mainly at formula (9), (12), (13) and the Algorithm 2.
self.pndm_order = 4
def create_state(self, common: Optional[CommonSchedulerState] = None) -> PNDMSchedulerState:
if common is None:
common = CommonSchedulerState.create(self)
# At every step in ddim, we are looking into the previous alphas_cumprod
# For the final step, there is no previous alphas_cumprod because we are already at 0
# `set_alpha_to_one` decides whether we set this parameter simply to one or
# whether we use the final alpha of the "non-previous" one.
final_alpha_cumprod = (
jnp.array(1.0, dtype=self.dtype) if self.config.set_alpha_to_one else common.alphas_cumprod[0]
)
# standard deviation of the initial noise distribution
init_noise_sigma = jnp.array(1.0, dtype=self.dtype)
timesteps = jnp.arange(0, self.config.num_train_timesteps).round()[::-1]
return PNDMSchedulerState.create(
common=common,
final_alpha_cumprod=final_alpha_cumprod,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
)
def set_timesteps(self, state: PNDMSchedulerState, num_inference_steps: int, shape: Tuple) -> PNDMSchedulerState:
"""
Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
state (`PNDMSchedulerState`):
the `FlaxPNDMScheduler` state data class instance.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
shape (`Tuple`):
the shape of the samples to be generated.
"""
step_ratio = self.config.num_train_timesteps // num_inference_steps
# creates integer timesteps by multiplying by ratio
# rounding to avoid issues when num_inference_step is power of 3
_timesteps = (jnp.arange(0, num_inference_steps) * step_ratio).round() + self.config.steps_offset
if self.config.skip_prk_steps:
# for some models like stable diffusion the prk steps can/should be skipped to
# produce better results. When using PNDM with `self.config.skip_prk_steps` the implementation
# is based on crowsonkb's PLMS sampler implementation: https://github.com/CompVis/latent-diffusion/pull/51
prk_timesteps = jnp.array([], dtype=jnp.int32)
plms_timesteps = jnp.concatenate([_timesteps[:-1], _timesteps[-2:-1], _timesteps[-1:]])[::-1]
else:
prk_timesteps = _timesteps[-self.pndm_order :].repeat(2) + jnp.tile(
jnp.array([0, self.config.num_train_timesteps // num_inference_steps // 2], dtype=jnp.int32),
self.pndm_order,
)
prk_timesteps = (prk_timesteps[:-1].repeat(2)[1:-1])[::-1]
plms_timesteps = _timesteps[:-3][::-1]
timesteps = jnp.concatenate([prk_timesteps, plms_timesteps])
# initial running values
cur_model_output = jnp.zeros(shape, dtype=self.dtype)
counter = jnp.int32(0)
cur_sample = jnp.zeros(shape, dtype=self.dtype)
ets = jnp.zeros((4,) + shape, dtype=self.dtype)
return state.replace(
timesteps=timesteps,
num_inference_steps=num_inference_steps,
prk_timesteps=prk_timesteps,
plms_timesteps=plms_timesteps,
cur_model_output=cur_model_output,
counter=counter,
cur_sample=cur_sample,
ets=ets,
)
def scale_model_input(
self, state: PNDMSchedulerState, sample: jnp.ndarray, timestep: Optional[int] = None
) -> jnp.ndarray:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
state (`PNDMSchedulerState`): the `FlaxPNDMScheduler` state data class instance.
sample (`jnp.ndarray`): input sample
timestep (`int`, optional): current timestep
Returns:
`jnp.ndarray`: scaled input sample
"""
return sample
def step(
self,
state: PNDMSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
return_dict: bool = True,
) -> Union[FlaxPNDMSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
This function calls `step_prk()` or `step_plms()` depending on the internal variable `counter`.
Args:
state (`PNDMSchedulerState`): the `FlaxPNDMScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
return_dict (`bool`): option for returning tuple rather than FlaxPNDMSchedulerOutput class
Returns:
[`FlaxPNDMSchedulerOutput`] or `tuple`: [`FlaxPNDMSchedulerOutput`] if `return_dict` is True, otherwise a
`tuple`. When returning a tuple, the first element is the sample tensor.
"""
if state.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if self.config.skip_prk_steps:
prev_sample, state = self.step_plms(state, model_output, timestep, sample)
else:
prk_prev_sample, prk_state = self.step_prk(state, model_output, timestep, sample)
plms_prev_sample, plms_state = self.step_plms(state, model_output, timestep, sample)
cond = state.counter < len(state.prk_timesteps)
prev_sample = jax.lax.select(cond, prk_prev_sample, plms_prev_sample)
state = state.replace(
cur_model_output=jax.lax.select(cond, prk_state.cur_model_output, plms_state.cur_model_output),
ets=jax.lax.select(cond, prk_state.ets, plms_state.ets),
cur_sample=jax.lax.select(cond, prk_state.cur_sample, plms_state.cur_sample),
counter=jax.lax.select(cond, prk_state.counter, plms_state.counter),
)
if not return_dict:
return (prev_sample, state)
return FlaxPNDMSchedulerOutput(prev_sample=prev_sample, state=state)
def step_prk(
self,
state: PNDMSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
) -> Union[FlaxPNDMSchedulerOutput, Tuple]:
"""
Step function propagating the sample with the Runge-Kutta method. RK takes 4 forward passes to approximate the
solution to the differential equation.
Args:
state (`PNDMSchedulerState`): the `FlaxPNDMScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
return_dict (`bool`): option for returning tuple rather than FlaxPNDMSchedulerOutput class
Returns:
[`FlaxPNDMSchedulerOutput`] or `tuple`: [`FlaxPNDMSchedulerOutput`] if `return_dict` is True, otherwise a
`tuple`. When returning a tuple, the first element is the sample tensor.
"""
if state.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
diff_to_prev = jnp.where(
state.counter % 2, 0, self.config.num_train_timesteps // state.num_inference_steps // 2
)
prev_timestep = timestep - diff_to_prev
timestep = state.prk_timesteps[state.counter // 4 * 4]
model_output = jax.lax.select(
(state.counter % 4) != 3,
model_output, # remainder 0, 1, 2
state.cur_model_output + 1 / 6 * model_output, # remainder 3
)
state = state.replace(
cur_model_output=jax.lax.select_n(
state.counter % 4,
state.cur_model_output + 1 / 6 * model_output, # remainder 0
state.cur_model_output + 1 / 3 * model_output, # remainder 1
state.cur_model_output + 1 / 3 * model_output, # remainder 2
jnp.zeros_like(state.cur_model_output), # remainder 3
),
ets=jax.lax.select(
(state.counter % 4) == 0,
state.ets.at[0:3].set(state.ets[1:4]).at[3].set(model_output), # remainder 0
state.ets, # remainder 1, 2, 3
),
cur_sample=jax.lax.select(
(state.counter % 4) == 0,
sample, # remainder 0
state.cur_sample, # remainder 1, 2, 3
),
)
cur_sample = state.cur_sample
prev_sample = self._get_prev_sample(state, cur_sample, timestep, prev_timestep, model_output)
state = state.replace(counter=state.counter + 1)
return (prev_sample, state)
def step_plms(
self,
state: PNDMSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
) -> Union[FlaxPNDMSchedulerOutput, Tuple]:
"""
Step function propagating the sample with the linear multi-step method. This has one forward pass with multiple
times to approximate the solution.
Args:
state (`PNDMSchedulerState`): the `FlaxPNDMScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
return_dict (`bool`): option for returning tuple rather than FlaxPNDMSchedulerOutput class
Returns:
[`FlaxPNDMSchedulerOutput`] or `tuple`: [`FlaxPNDMSchedulerOutput`] if `return_dict` is True, otherwise a
`tuple`. When returning a tuple, the first element is the sample tensor.
"""
if state.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
# NOTE: There is no way to check in the jitted runtime if the prk mode was ran before
prev_timestep = timestep - self.config.num_train_timesteps // state.num_inference_steps
prev_timestep = jnp.where(prev_timestep > 0, prev_timestep, 0)
# Reference:
# if state.counter != 1:
# state.ets.append(model_output)
# else:
# prev_timestep = timestep
# timestep = timestep + self.config.num_train_timesteps // state.num_inference_steps
prev_timestep = jnp.where(state.counter == 1, timestep, prev_timestep)
timestep = jnp.where(
state.counter == 1, timestep + self.config.num_train_timesteps // state.num_inference_steps, timestep
)
# Reference:
# if len(state.ets) == 1 and state.counter == 0:
# model_output = model_output
# state.cur_sample = sample
# elif len(state.ets) == 1 and state.counter == 1:
# model_output = (model_output + state.ets[-1]) / 2
# sample = state.cur_sample
# state.cur_sample = None
# elif len(state.ets) == 2:
# model_output = (3 * state.ets[-1] - state.ets[-2]) / 2
# elif len(state.ets) == 3:
# model_output = (23 * state.ets[-1] - 16 * state.ets[-2] + 5 * state.ets[-3]) / 12
# else:
# model_output = (1 / 24) * (55 * state.ets[-1] - 59 * state.ets[-2] + 37 * state.ets[-3] - 9 * state.ets[-4])
state = state.replace(
ets=jax.lax.select(
state.counter != 1,
state.ets.at[0:3].set(state.ets[1:4]).at[3].set(model_output), # counter != 1
state.ets, # counter 1
),
cur_sample=jax.lax.select(
state.counter != 1,
sample, # counter != 1
state.cur_sample, # counter 1
),
)
state = state.replace(
cur_model_output=jax.lax.select_n(
jnp.clip(state.counter, 0, 4),
model_output, # counter 0
(model_output + state.ets[-1]) / 2, # counter 1
(3 * state.ets[-1] - state.ets[-2]) / 2, # counter 2
(23 * state.ets[-1] - 16 * state.ets[-2] + 5 * state.ets[-3]) / 12, # counter 3
(1 / 24)
* (55 * state.ets[-1] - 59 * state.ets[-2] + 37 * state.ets[-3] - 9 * state.ets[-4]), # counter >= 4
),
)
sample = state.cur_sample
model_output = state.cur_model_output
prev_sample = self._get_prev_sample(state, sample, timestep, prev_timestep, model_output)
state = state.replace(counter=state.counter + 1)
return (prev_sample, state)
def _get_prev_sample(self, state: PNDMSchedulerState, sample, timestep, prev_timestep, model_output):
# See formula (9) of PNDM paper https://arxiv.org/pdf/2202.09778.pdf
# this function computes x_(t−δ) using the formula of (9)
# Note that x_t needs to be added to both sides of the equation
# Notation (<variable name> -> <name in paper>
# alpha_prod_t -> α_t
# alpha_prod_t_prev -> α_(t−δ)
# beta_prod_t -> (1 - α_t)
# beta_prod_t_prev -> (1 - α_(t−δ))
# sample -> x_t
# model_output -> e_θ(x_t, t)
# prev_sample -> x_(t−δ)
alpha_prod_t = state.common.alphas_cumprod[timestep]
alpha_prod_t_prev = jnp.where(
prev_timestep >= 0, state.common.alphas_cumprod[prev_timestep], state.final_alpha_cumprod
)
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
if self.config.prediction_type == "v_prediction":
model_output = (alpha_prod_t**0.5) * model_output + (beta_prod_t**0.5) * sample
elif self.config.prediction_type != "epsilon":
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon` or `v_prediction`"
)
# corresponds to (α_(t−δ) - α_t) divided by
# denominator of x_t in formula (9) and plus 1
# Note: (α_(t−δ) - α_t) / (sqrt(α_t) * (sqrt(α_(t−δ)) + sqr(α_t))) =
# sqrt(α_(t−δ)) / sqrt(α_t))
sample_coeff = (alpha_prod_t_prev / alpha_prod_t) ** (0.5)
# corresponds to denominator of e_θ(x_t, t) in formula (9)
model_output_denom_coeff = alpha_prod_t * beta_prod_t_prev ** (0.5) + (
alpha_prod_t * beta_prod_t * alpha_prod_t_prev
) ** (0.5)
# full formula (9)
prev_sample = (
sample_coeff * sample - (alpha_prod_t_prev - alpha_prod_t) * model_output / model_output_denom_coeff
)
return prev_sample
def add_noise(
self,
state: PNDMSchedulerState,
original_samples: jnp.ndarray,
noise: jnp.ndarray,
timesteps: jnp.ndarray,
) -> jnp.ndarray:
return add_noise_common(state.common, original_samples, noise, timesteps)
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_pndm_flax.py |
# Copyright 2023 Google Brain and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/yang-song/score_sde_pytorch
import math
from typing import Union
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import SchedulerMixin
class ScoreSdeVpScheduler(SchedulerMixin, ConfigMixin):
"""
`ScoreSdeVpScheduler` is a variance preserving stochastic differential equation (SDE) scheduler.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 2000):
The number of diffusion steps to train the model.
beta_min (`int`, defaults to 0.1):
beta_max (`int`, defaults to 20):
sampling_eps (`int`, defaults to 1e-3):
The end value of sampling where timesteps decrease progressively from 1 to epsilon.
"""
order = 1
@register_to_config
def __init__(self, num_train_timesteps=2000, beta_min=0.1, beta_max=20, sampling_eps=1e-3):
self.sigmas = None
self.discrete_sigmas = None
self.timesteps = None
def set_timesteps(self, num_inference_steps, device: Union[str, torch.device] = None):
"""
Sets the continuous timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.timesteps = torch.linspace(1, self.config.sampling_eps, num_inference_steps, device=device)
def step_pred(self, score, x, t, generator=None):
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
score ():
x ():
t ():
generator (`torch.Generator`, *optional*):
A random number generator.
"""
if self.timesteps is None:
raise ValueError(
"`self.timesteps` is not set, you need to run 'set_timesteps' after creating the scheduler"
)
# TODO(Patrick) better comments + non-PyTorch
# postprocess model score
log_mean_coeff = (
-0.25 * t**2 * (self.config.beta_max - self.config.beta_min) - 0.5 * t * self.config.beta_min
)
std = torch.sqrt(1.0 - torch.exp(2.0 * log_mean_coeff))
std = std.flatten()
while len(std.shape) < len(score.shape):
std = std.unsqueeze(-1)
score = -score / std
# compute
dt = -1.0 / len(self.timesteps)
beta_t = self.config.beta_min + t * (self.config.beta_max - self.config.beta_min)
beta_t = beta_t.flatten()
while len(beta_t.shape) < len(x.shape):
beta_t = beta_t.unsqueeze(-1)
drift = -0.5 * beta_t * x
diffusion = torch.sqrt(beta_t)
drift = drift - diffusion**2 * score
x_mean = x + drift * dt
# add noise
noise = randn_tensor(x.shape, layout=x.layout, generator=generator, device=x.device, dtype=x.dtype)
x = x_mean + diffusion * math.sqrt(-dt) * noise
return x, x_mean
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_sde_vp.py |
# Copyright 2023 UC Berkeley Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import flax
import jax
import jax.numpy as jnp
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils_flax import (
CommonSchedulerState,
FlaxKarrasDiffusionSchedulers,
FlaxSchedulerMixin,
FlaxSchedulerOutput,
add_noise_common,
get_velocity_common,
)
@flax.struct.dataclass
class DDPMSchedulerState:
common: CommonSchedulerState
# setable values
init_noise_sigma: jnp.ndarray
timesteps: jnp.ndarray
num_inference_steps: Optional[int] = None
@classmethod
def create(cls, common: CommonSchedulerState, init_noise_sigma: jnp.ndarray, timesteps: jnp.ndarray):
return cls(common=common, init_noise_sigma=init_noise_sigma, timesteps=timesteps)
@dataclass
class FlaxDDPMSchedulerOutput(FlaxSchedulerOutput):
state: DDPMSchedulerState
class FlaxDDPMScheduler(FlaxSchedulerMixin, ConfigMixin):
"""
Denoising diffusion probabilistic models (DDPMs) explores the connections between denoising score matching and
Langevin dynamics sampling.
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details, see the original paper: https://arxiv.org/abs/2006.11239
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
beta_start (`float`): the starting `beta` value of inference.
beta_end (`float`): the final `beta` value.
beta_schedule (`str`):
the beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, optional):
option to pass an array of betas directly to the constructor to bypass `beta_start`, `beta_end` etc.
variance_type (`str`):
options to clip the variance used when adding noise to the denoised sample. Choose from `fixed_small`,
`fixed_small_log`, `fixed_large`, `fixed_large_log`, `learned` or `learned_range`.
clip_sample (`bool`, default `True`):
option to clip predicted sample between -1 and 1 for numerical stability.
prediction_type (`str`, default `epsilon`):
indicates whether the model predicts the noise (epsilon), or the samples. One of `epsilon`, `sample`.
`v-prediction` is not supported for this scheduler.
dtype (`jnp.dtype`, *optional*, defaults to `jnp.float32`):
the `dtype` used for params and computation.
"""
_compatibles = [e.name for e in FlaxKarrasDiffusionSchedulers]
dtype: jnp.dtype
@property
def has_state(self):
return True
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[jnp.ndarray] = None,
variance_type: str = "fixed_small",
clip_sample: bool = True,
prediction_type: str = "epsilon",
dtype: jnp.dtype = jnp.float32,
):
self.dtype = dtype
def create_state(self, common: Optional[CommonSchedulerState] = None) -> DDPMSchedulerState:
if common is None:
common = CommonSchedulerState.create(self)
# standard deviation of the initial noise distribution
init_noise_sigma = jnp.array(1.0, dtype=self.dtype)
timesteps = jnp.arange(0, self.config.num_train_timesteps).round()[::-1]
return DDPMSchedulerState.create(
common=common,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
)
def scale_model_input(
self, state: DDPMSchedulerState, sample: jnp.ndarray, timestep: Optional[int] = None
) -> jnp.ndarray:
"""
Args:
state (`PNDMSchedulerState`): the `FlaxPNDMScheduler` state data class instance.
sample (`jnp.ndarray`): input sample
timestep (`int`, optional): current timestep
Returns:
`jnp.ndarray`: scaled input sample
"""
return sample
def set_timesteps(
self, state: DDPMSchedulerState, num_inference_steps: int, shape: Tuple = ()
) -> DDPMSchedulerState:
"""
Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
state (`DDIMSchedulerState`):
the `FlaxDDPMScheduler` state data class instance.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
"""
step_ratio = self.config.num_train_timesteps // num_inference_steps
# creates integer timesteps by multiplying by ratio
# rounding to avoid issues when num_inference_step is power of 3
timesteps = (jnp.arange(0, num_inference_steps) * step_ratio).round()[::-1]
return state.replace(
num_inference_steps=num_inference_steps,
timesteps=timesteps,
)
def _get_variance(self, state: DDPMSchedulerState, t, predicted_variance=None, variance_type=None):
alpha_prod_t = state.common.alphas_cumprod[t]
alpha_prod_t_prev = jnp.where(t > 0, state.common.alphas_cumprod[t - 1], jnp.array(1.0, dtype=self.dtype))
# For t > 0, compute predicted variance βt (see formula (6) and (7) from https://arxiv.org/pdf/2006.11239.pdf)
# and sample from it to get previous sample
# x_{t-1} ~ N(pred_prev_sample, variance) == add variance to pred_sample
variance = (1 - alpha_prod_t_prev) / (1 - alpha_prod_t) * state.common.betas[t]
if variance_type is None:
variance_type = self.config.variance_type
# hacks - were probably added for training stability
if variance_type == "fixed_small":
variance = jnp.clip(variance, a_min=1e-20)
# for rl-diffuser https://arxiv.org/abs/2205.09991
elif variance_type == "fixed_small_log":
variance = jnp.log(jnp.clip(variance, a_min=1e-20))
elif variance_type == "fixed_large":
variance = state.common.betas[t]
elif variance_type == "fixed_large_log":
# Glide max_log
variance = jnp.log(state.common.betas[t])
elif variance_type == "learned":
return predicted_variance
elif variance_type == "learned_range":
min_log = variance
max_log = state.common.betas[t]
frac = (predicted_variance + 1) / 2
variance = frac * max_log + (1 - frac) * min_log
return variance
def step(
self,
state: DDPMSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
key: Optional[jax.random.KeyArray] = None,
return_dict: bool = True,
) -> Union[FlaxDDPMSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
state (`DDPMSchedulerState`): the `FlaxDDPMScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
key (`jax.random.KeyArray`): a PRNG key.
return_dict (`bool`): option for returning tuple rather than FlaxDDPMSchedulerOutput class
Returns:
[`FlaxDDPMSchedulerOutput`] or `tuple`: [`FlaxDDPMSchedulerOutput`] if `return_dict` is True, otherwise a
`tuple`. When returning a tuple, the first element is the sample tensor.
"""
t = timestep
if key is None:
key = jax.random.PRNGKey(0)
if model_output.shape[1] == sample.shape[1] * 2 and self.config.variance_type in ["learned", "learned_range"]:
model_output, predicted_variance = jnp.split(model_output, sample.shape[1], axis=1)
else:
predicted_variance = None
# 1. compute alphas, betas
alpha_prod_t = state.common.alphas_cumprod[t]
alpha_prod_t_prev = jnp.where(t > 0, state.common.alphas_cumprod[t - 1], jnp.array(1.0, dtype=self.dtype))
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
# 2. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample` "
" for the FlaxDDPMScheduler."
)
# 3. Clip "predicted x_0"
if self.config.clip_sample:
pred_original_sample = jnp.clip(pred_original_sample, -1, 1)
# 4. Compute coefficients for pred_original_sample x_0 and current sample x_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_original_sample_coeff = (alpha_prod_t_prev ** (0.5) * state.common.betas[t]) / beta_prod_t
current_sample_coeff = state.common.alphas[t] ** (0.5) * beta_prod_t_prev / beta_prod_t
# 5. Compute predicted previous sample µ_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_prev_sample = pred_original_sample_coeff * pred_original_sample + current_sample_coeff * sample
# 6. Add noise
def random_variance():
split_key = jax.random.split(key, num=1)
noise = jax.random.normal(split_key, shape=model_output.shape, dtype=self.dtype)
return (self._get_variance(state, t, predicted_variance=predicted_variance) ** 0.5) * noise
variance = jnp.where(t > 0, random_variance(), jnp.zeros(model_output.shape, dtype=self.dtype))
pred_prev_sample = pred_prev_sample + variance
if not return_dict:
return (pred_prev_sample, state)
return FlaxDDPMSchedulerOutput(prev_sample=pred_prev_sample, state=state)
def add_noise(
self,
state: DDPMSchedulerState,
original_samples: jnp.ndarray,
noise: jnp.ndarray,
timesteps: jnp.ndarray,
) -> jnp.ndarray:
return add_noise_common(state.common, original_samples, noise, timesteps)
def get_velocity(
self,
state: DDPMSchedulerState,
sample: jnp.ndarray,
noise: jnp.ndarray,
timesteps: jnp.ndarray,
) -> jnp.ndarray:
return get_velocity_common(state.common, sample, noise, timesteps)
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_ddpm_flax.py |
# Copyright 2023 Katherine Crowson, The HuggingFace Team and hlky. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from collections import defaultdict
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
import torchsde
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
class BatchedBrownianTree:
"""A wrapper around torchsde.BrownianTree that enables batches of entropy."""
def __init__(self, x, t0, t1, seed=None, **kwargs):
t0, t1, self.sign = self.sort(t0, t1)
w0 = kwargs.get("w0", torch.zeros_like(x))
if seed is None:
seed = torch.randint(0, 2**63 - 1, []).item()
self.batched = True
try:
assert len(seed) == x.shape[0]
w0 = w0[0]
except TypeError:
seed = [seed]
self.batched = False
self.trees = [torchsde.BrownianTree(t0, w0, t1, entropy=s, **kwargs) for s in seed]
@staticmethod
def sort(a, b):
return (a, b, 1) if a < b else (b, a, -1)
def __call__(self, t0, t1):
t0, t1, sign = self.sort(t0, t1)
w = torch.stack([tree(t0, t1) for tree in self.trees]) * (self.sign * sign)
return w if self.batched else w[0]
class BrownianTreeNoiseSampler:
"""A noise sampler backed by a torchsde.BrownianTree.
Args:
x (Tensor): The tensor whose shape, device and dtype to use to generate
random samples.
sigma_min (float): The low end of the valid interval.
sigma_max (float): The high end of the valid interval.
seed (int or List[int]): The random seed. If a list of seeds is
supplied instead of a single integer, then the noise sampler will use one BrownianTree per batch item, each
with its own seed.
transform (callable): A function that maps sigma to the sampler's
internal timestep.
"""
def __init__(self, x, sigma_min, sigma_max, seed=None, transform=lambda x: x):
self.transform = transform
t0, t1 = self.transform(torch.as_tensor(sigma_min)), self.transform(torch.as_tensor(sigma_max))
self.tree = BatchedBrownianTree(x, t0, t1, seed)
def __call__(self, sigma, sigma_next):
t0, t1 = self.transform(torch.as_tensor(sigma)), self.transform(torch.as_tensor(sigma_next))
return self.tree(t0, t1) / (t1 - t0).abs().sqrt()
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DPMSolverSDEScheduler(SchedulerMixin, ConfigMixin):
"""
DPMSolverSDEScheduler implements the stochastic sampler from the [Elucidating the Design Space of Diffusion-Based
Generative Models](https://huggingface.co/papers/2206.00364) paper.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.00085):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.012):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
noise_sampler_seed (`int`, *optional*, defaults to `None`):
The random seed to use for the noise sampler. If `None`, a random seed is generated.
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 2
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.00085, # sensible defaults
beta_end: float = 0.012,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
prediction_type: str = "epsilon",
use_karras_sigmas: Optional[bool] = False,
noise_sampler_seed: Optional[int] = None,
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# set all values
self.set_timesteps(num_train_timesteps, None, num_train_timesteps)
self.use_karras_sigmas = use_karras_sigmas
self.noise_sampler = None
self.noise_sampler_seed = noise_sampler_seed
self._step_index = None
# Copied from diffusers.schedulers.scheduling_heun_discrete.HeunDiscreteScheduler.index_for_timestep
def index_for_timestep(self, timestep, schedule_timesteps=None):
if schedule_timesteps is None:
schedule_timesteps = self.timesteps
indices = (schedule_timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(self._index_counter) == 0:
pos = 1 if len(indices) > 1 else 0
else:
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
pos = self._index_counter[timestep_int]
return indices[pos].item()
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
@property
def init_noise_sigma(self):
# standard deviation of the initial noise distribution
if self.config.timestep_spacing in ["linspace", "trailing"]:
return self.sigmas.max()
return (self.sigmas.max() ** 2 + 1) ** 0.5
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self,
sample: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
sigma_input = sigma if self.state_in_first_order else self.mid_point_sigma
sample = sample / ((sigma_input**2 + 1) ** 0.5)
return sample
def set_timesteps(
self,
num_inference_steps: int,
device: Union[str, torch.device] = None,
num_train_timesteps: Optional[int] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
num_train_timesteps = num_train_timesteps or self.config.num_train_timesteps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = np.linspace(0, num_train_timesteps - 1, num_inference_steps, dtype=float)[::-1].copy()
elif self.config.timestep_spacing == "leading":
step_ratio = num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(float)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(num_train_timesteps, 0, -step_ratio)).round().copy().astype(float)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
log_sigmas = np.log(sigmas)
sigmas = np.interp(timesteps, np.arange(0, len(sigmas)), sigmas)
if self.use_karras_sigmas:
sigmas = self._convert_to_karras(in_sigmas=sigmas)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas])
second_order_timesteps = self._second_order_timesteps(sigmas, log_sigmas)
sigmas = np.concatenate([sigmas, [0.0]]).astype(np.float32)
sigmas = torch.from_numpy(sigmas).to(device=device)
self.sigmas = torch.cat([sigmas[:1], sigmas[1:-1].repeat_interleave(2), sigmas[-1:]])
timesteps = torch.from_numpy(timesteps)
second_order_timesteps = torch.from_numpy(second_order_timesteps)
timesteps = torch.cat([timesteps[:1], timesteps[1:].repeat_interleave(2)])
timesteps[1::2] = second_order_timesteps
if str(device).startswith("mps"):
# mps does not support float64
self.timesteps = timesteps.to(device, dtype=torch.float32)
else:
self.timesteps = timesteps.to(device=device)
# empty first order variables
self.sample = None
self.mid_point_sigma = None
self._step_index = None
self.noise_sampler = None
# for exp beta schedules, such as the one for `pipeline_shap_e.py`
# we need an index counter
self._index_counter = defaultdict(int)
def _second_order_timesteps(self, sigmas, log_sigmas):
def sigma_fn(_t):
return np.exp(-_t)
def t_fn(_sigma):
return -np.log(_sigma)
midpoint_ratio = 0.5
t = t_fn(sigmas)
delta_time = np.diff(t)
t_proposed = t[:-1] + delta_time * midpoint_ratio
sig_proposed = sigma_fn(t_proposed)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sig_proposed])
return timesteps
# copied from diffusers.schedulers.scheduling_euler_discrete._sigma_to_t
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# copied from diffusers.schedulers.scheduling_euler_discrete._convert_to_karras
def _convert_to_karras(self, in_sigmas: torch.FloatTensor) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, self.num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
@property
def state_in_first_order(self):
return self.sample is None
def step(
self,
model_output: Union[torch.FloatTensor, np.ndarray],
timestep: Union[float, torch.FloatTensor],
sample: Union[torch.FloatTensor, np.ndarray],
return_dict: bool = True,
s_noise: float = 1.0,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor` or `np.ndarray`):
The direct output from learned diffusion model.
timestep (`float` or `torch.FloatTensor`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor` or `np.ndarray`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
s_noise (`float`, *optional*, defaults to 1.0):
Scaling factor for noise added to the sample.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.step_index is None:
self._init_step_index(timestep)
# advance index counter by 1
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
self._index_counter[timestep_int] += 1
# Create a noise sampler if it hasn't been created yet
if self.noise_sampler is None:
min_sigma, max_sigma = self.sigmas[self.sigmas > 0].min(), self.sigmas.max()
self.noise_sampler = BrownianTreeNoiseSampler(sample, min_sigma, max_sigma, self.noise_sampler_seed)
# Define functions to compute sigma and t from each other
def sigma_fn(_t: torch.FloatTensor) -> torch.FloatTensor:
return _t.neg().exp()
def t_fn(_sigma: torch.FloatTensor) -> torch.FloatTensor:
return _sigma.log().neg()
if self.state_in_first_order:
sigma = self.sigmas[self.step_index]
sigma_next = self.sigmas[self.step_index + 1]
else:
# 2nd order
sigma = self.sigmas[self.step_index - 1]
sigma_next = self.sigmas[self.step_index]
# Set the midpoint and step size for the current step
midpoint_ratio = 0.5
t, t_next = t_fn(sigma), t_fn(sigma_next)
delta_time = t_next - t
t_proposed = t + delta_time * midpoint_ratio
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
if self.config.prediction_type == "epsilon":
sigma_input = sigma if self.state_in_first_order else sigma_fn(t_proposed)
pred_original_sample = sample - sigma_input * model_output
elif self.config.prediction_type == "v_prediction":
sigma_input = sigma if self.state_in_first_order else sigma_fn(t_proposed)
pred_original_sample = model_output * (-sigma_input / (sigma_input**2 + 1) ** 0.5) + (
sample / (sigma_input**2 + 1)
)
elif self.config.prediction_type == "sample":
raise NotImplementedError("prediction_type not implemented yet: sample")
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
if sigma_next == 0:
derivative = (sample - pred_original_sample) / sigma
dt = sigma_next - sigma
prev_sample = sample + derivative * dt
else:
if self.state_in_first_order:
t_next = t_proposed
else:
sample = self.sample
sigma_from = sigma_fn(t)
sigma_to = sigma_fn(t_next)
sigma_up = min(sigma_to, (sigma_to**2 * (sigma_from**2 - sigma_to**2) / sigma_from**2) ** 0.5)
sigma_down = (sigma_to**2 - sigma_up**2) ** 0.5
ancestral_t = t_fn(sigma_down)
prev_sample = (sigma_fn(ancestral_t) / sigma_fn(t)) * sample - (
t - ancestral_t
).expm1() * pred_original_sample
prev_sample = prev_sample + self.noise_sampler(sigma_fn(t), sigma_fn(t_next)) * s_noise * sigma_up
if self.state_in_first_order:
# store for 2nd order step
self.sample = sample
self.mid_point_sigma = sigma_fn(t_next)
else:
# free for "first order mode"
self.sample = None
self.mid_point_sigma = None
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
# Copied from diffusers.schedulers.scheduling_heun_discrete.HeunDiscreteScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [self.index_for_timestep(t, schedule_timesteps) for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_dpmsolver_sde.py |
# Copyright 2023 NVIDIA and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import SchedulerMixin
@dataclass
class KarrasVeOutput(BaseOutput):
"""
Output class for the scheduler's step function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
derivative (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Derivative of predicted original image sample (x_0).
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample (x_{0}) based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
derivative: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
class KarrasVeScheduler(SchedulerMixin, ConfigMixin):
"""
A stochastic scheduler tailored to variance-expanding models.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
<Tip>
For more details on the parameters, see [Appendix E](https://arxiv.org/abs/2206.00364). The grid search values used
to find the optimal `{s_noise, s_churn, s_min, s_max}` for a specific model are described in Table 5 of the paper.
</Tip>
Args:
sigma_min (`float`, defaults to 0.02):
The minimum noise magnitude.
sigma_max (`float`, defaults to 100):
The maximum noise magnitude.
s_noise (`float`, defaults to 1.007):
The amount of additional noise to counteract loss of detail during sampling. A reasonable range is [1.000,
1.011].
s_churn (`float`, defaults to 80):
The parameter controlling the overall amount of stochasticity. A reasonable range is [0, 100].
s_min (`float`, defaults to 0.05):
The start value of the sigma range to add noise (enable stochasticity). A reasonable range is [0, 10].
s_max (`float`, defaults to 50):
The end value of the sigma range to add noise. A reasonable range is [0.2, 80].
"""
order = 2
@register_to_config
def __init__(
self,
sigma_min: float = 0.02,
sigma_max: float = 100,
s_noise: float = 1.007,
s_churn: float = 80,
s_min: float = 0.05,
s_max: float = 50,
):
# standard deviation of the initial noise distribution
self.init_noise_sigma = sigma_max
# setable values
self.num_inference_steps: int = None
self.timesteps: np.IntTensor = None
self.schedule: torch.FloatTensor = None # sigma(t_i)
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
timesteps = np.arange(0, self.num_inference_steps)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps).to(device)
schedule = [
(
self.config.sigma_max**2
* (self.config.sigma_min**2 / self.config.sigma_max**2) ** (i / (num_inference_steps - 1))
)
for i in self.timesteps
]
self.schedule = torch.tensor(schedule, dtype=torch.float32, device=device)
def add_noise_to_input(
self, sample: torch.FloatTensor, sigma: float, generator: Optional[torch.Generator] = None
) -> Tuple[torch.FloatTensor, float]:
"""
Explicit Langevin-like "churn" step of adding noise to the sample according to a `gamma_i ≥ 0` to reach a
higher noise level `sigma_hat = sigma_i + gamma_i*sigma_i`.
Args:
sample (`torch.FloatTensor`):
The input sample.
sigma (`float`):
generator (`torch.Generator`, *optional*):
A random number generator.
"""
if self.config.s_min <= sigma <= self.config.s_max:
gamma = min(self.config.s_churn / self.num_inference_steps, 2**0.5 - 1)
else:
gamma = 0
# sample eps ~ N(0, S_noise^2 * I)
eps = self.config.s_noise * randn_tensor(sample.shape, generator=generator).to(sample.device)
sigma_hat = sigma + gamma * sigma
sample_hat = sample + ((sigma_hat**2 - sigma**2) ** 0.5 * eps)
return sample_hat, sigma_hat
def step(
self,
model_output: torch.FloatTensor,
sigma_hat: float,
sigma_prev: float,
sample_hat: torch.FloatTensor,
return_dict: bool = True,
) -> Union[KarrasVeOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
sigma_hat (`float`):
sigma_prev (`float`):
sample_hat (`torch.FloatTensor`):
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_karras_ve.KarrasVESchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_karras_ve.KarrasVESchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_karras_ve.KarrasVESchedulerOutput`] is returned,
otherwise a tuple is returned where the first element is the sample tensor.
"""
pred_original_sample = sample_hat + sigma_hat * model_output
derivative = (sample_hat - pred_original_sample) / sigma_hat
sample_prev = sample_hat + (sigma_prev - sigma_hat) * derivative
if not return_dict:
return (sample_prev, derivative)
return KarrasVeOutput(
prev_sample=sample_prev, derivative=derivative, pred_original_sample=pred_original_sample
)
def step_correct(
self,
model_output: torch.FloatTensor,
sigma_hat: float,
sigma_prev: float,
sample_hat: torch.FloatTensor,
sample_prev: torch.FloatTensor,
derivative: torch.FloatTensor,
return_dict: bool = True,
) -> Union[KarrasVeOutput, Tuple]:
"""
Corrects the predicted sample based on the `model_output` of the network.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
sigma_hat (`float`): TODO
sigma_prev (`float`): TODO
sample_hat (`torch.FloatTensor`): TODO
sample_prev (`torch.FloatTensor`): TODO
derivative (`torch.FloatTensor`): TODO
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_ddpm.DDPMSchedulerOutput`] or `tuple`.
Returns:
prev_sample (TODO): updated sample in the diffusion chain. derivative (TODO): TODO
"""
pred_original_sample = sample_prev + sigma_prev * model_output
derivative_corr = (sample_prev - pred_original_sample) / sigma_prev
sample_prev = sample_hat + (sigma_prev - sigma_hat) * (0.5 * derivative + 0.5 * derivative_corr)
if not return_dict:
return (sample_prev, derivative)
return KarrasVeOutput(
prev_sample=sample_prev, derivative=derivative, pred_original_sample=pred_original_sample
)
def add_noise(self, original_samples, noise, timesteps):
raise NotImplementedError()
| diffusers-main | src/diffusers/schedulers/scheduling_karras_ve.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This code is strongly influenced by https://github.com/pesser/pytorch_diffusion
# and https://github.com/hojonathanho/diffusion
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from diffusers.configuration_utils import ConfigMixin, register_to_config
from diffusers.schedulers.scheduling_utils import SchedulerMixin
from diffusers.utils import BaseOutput, deprecate
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput with DDPM->DDIM
class DDIMSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
# Copied from diffusers.schedulers.scheduling_ddim.rescale_zero_terminal_snr
def rescale_zero_terminal_snr(betas):
"""
Rescales betas to have zero terminal SNR Based on https://arxiv.org/pdf/2305.08891.pdf (Algorithm 1)
Args:
betas (`torch.FloatTensor`):
the betas that the scheduler is being initialized with.
Returns:
`torch.FloatTensor`: rescaled betas with zero terminal SNR
"""
# Convert betas to alphas_bar_sqrt
alphas = 1.0 - betas
alphas_cumprod = torch.cumprod(alphas, dim=0)
alphas_bar_sqrt = alphas_cumprod.sqrt()
# Store old values.
alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
# Shift so the last timestep is zero.
alphas_bar_sqrt -= alphas_bar_sqrt_T
# Scale so the first timestep is back to the old value.
alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
# Convert alphas_bar_sqrt to betas
alphas_bar = alphas_bar_sqrt**2 # Revert sqrt
alphas = alphas_bar[1:] / alphas_bar[:-1] # Revert cumprod
alphas = torch.cat([alphas_bar[0:1], alphas])
betas = 1 - alphas
return betas
class DDIMInverseScheduler(SchedulerMixin, ConfigMixin):
"""
`DDIMInverseScheduler` is the reverse scheduler of [`DDIMScheduler`].
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
clip_sample (`bool`, defaults to `True`):
Clip the predicted sample for numerical stability.
clip_sample_range (`float`, defaults to 1.0):
The maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
set_alpha_to_one (`bool`, defaults to `True`):
Each diffusion step uses the alphas product value at that step and at the previous one. For the final step
there is no previous alpha. When this option is `True` the previous alpha product is fixed to 0, otherwise
it uses the alpha value at step `num_train_timesteps - 1`.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use `num_train_timesteps - 1` for the previous alpha
product.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
timestep_spacing (`str`, defaults to `"leading"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
rescale_betas_zero_snr (`bool`, defaults to `False`):
Whether to rescale the betas to have zero terminal SNR. This enables the model to generate very bright and
dark samples instead of limiting it to samples with medium brightness. Loosely related to
[`--offset_noise`](https://github.com/huggingface/diffusers/blob/74fd735eb073eb1d774b1ab4154a0876eb82f055/examples/dreambooth/train_dreambooth.py#L506).
"""
order = 1
ignore_for_config = ["kwargs"]
_deprecated_kwargs = ["set_alpha_to_zero"]
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
clip_sample: bool = True,
set_alpha_to_one: bool = True,
steps_offset: int = 0,
prediction_type: str = "epsilon",
clip_sample_range: float = 1.0,
timestep_spacing: str = "leading",
rescale_betas_zero_snr: bool = False,
**kwargs,
):
if kwargs.get("set_alpha_to_zero", None) is not None:
deprecation_message = (
"The `set_alpha_to_zero` argument is deprecated. Please use `set_alpha_to_one` instead."
)
deprecate("set_alpha_to_zero", "1.0.0", deprecation_message, standard_warn=False)
set_alpha_to_one = kwargs["set_alpha_to_zero"]
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
# Rescale for zero SNR
if rescale_betas_zero_snr:
self.betas = rescale_zero_terminal_snr(self.betas)
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# At every step in inverted ddim, we are looking into the next alphas_cumprod
# For the initial step, there is no current alphas_cumprod, and the index is out of bounds
# `set_alpha_to_one` decides whether we set this parameter simply to one
# in this case, self.step() just output the predicted noise
# or whether we use the initial alpha used in training the diffusion model.
self.initial_alpha_cumprod = torch.tensor(1.0) if set_alpha_to_one else self.alphas_cumprod[0]
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# setable values
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps).copy().astype(np.int64))
# Copied from diffusers.schedulers.scheduling_ddim.DDIMScheduler.scale_model_input
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
"""
if num_inference_steps > self.config.num_train_timesteps:
raise ValueError(
f"`num_inference_steps`: {num_inference_steps} cannot be larger than `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps} as the unet model trained with this scheduler can only handle"
f" maximal {self.config.num_train_timesteps} timesteps."
)
self.num_inference_steps = num_inference_steps
# "leading" and "trailing" corresponds to annotation of Table 1. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round().copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.round(np.arange(self.config.num_train_timesteps, 0, -step_ratio)[::-1]).astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'leading' or 'trailing'."
)
# Roll timesteps array by one to reflect reversed origin and destination semantics for each step
timesteps = np.roll(timesteps, 1)
timesteps[0] = int(timesteps[1] - step_ratio)
self.timesteps = torch.from_numpy(timesteps).to(device)
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
eta: float = 0.0,
use_clipped_model_output: bool = False,
variance_noise: Optional[torch.FloatTensor] = None,
return_dict: bool = True,
) -> Union[DDIMSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
eta (`float`):
The weight of noise for added noise in diffusion step.
use_clipped_model_output (`bool`, defaults to `False`):
If `True`, computes "corrected" `model_output` from the clipped predicted original sample. Necessary
because predicted original sample is clipped to [-1, 1] when `self.config.clip_sample` is `True`. If no
clipping has happened, "corrected" `model_output` would coincide with the one provided as input and
`use_clipped_model_output` has no effect.
variance_noise (`torch.FloatTensor`):
Alternative to generating noise with `generator` by directly providing the noise for the variance
itself. Useful for methods such as [`CycleDiffusion`].
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_ddim_inverse.DDIMInverseSchedulerOutput`] or
`tuple`.
Returns:
[`~schedulers.scheduling_ddim_inverse.DDIMInverseSchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_ddim_inverse.DDIMInverseSchedulerOutput`] is
returned, otherwise a tuple is returned where the first element is the sample tensor.
"""
# 1. get previous step value (=t+1)
prev_timestep = timestep + self.config.num_train_timesteps // self.num_inference_steps
# 2. compute alphas, betas
# change original implementation to exactly match noise levels for analogous forward process
alpha_prod_t = self.alphas_cumprod[timestep] if timestep >= 0 else self.initial_alpha_cumprod
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep]
beta_prod_t = 1 - alpha_prod_t
# 3. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
pred_epsilon = model_output
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
pred_epsilon = (alpha_prod_t**0.5) * model_output + (beta_prod_t**0.5) * sample
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction`"
)
# 4. Clip or threshold "predicted x_0"
if self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
# 5. compute "direction pointing to x_t" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
pred_sample_direction = (1 - alpha_prod_t_prev) ** (0.5) * pred_epsilon
# 6. compute x_t without "random noise" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
prev_sample = alpha_prod_t_prev ** (0.5) * pred_original_sample + pred_sample_direction
if not return_dict:
return (prev_sample, pred_original_sample)
return DDIMSchedulerOutput(prev_sample=prev_sample, pred_original_sample=pred_original_sample)
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_ddim_inverse.py |
# Copyright 2023 Google Brain and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/yang-song/score_sde_pytorch
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import flax
import jax.numpy as jnp
from jax import random
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils_flax import FlaxSchedulerMixin, FlaxSchedulerOutput, broadcast_to_shape_from_left
@flax.struct.dataclass
class ScoreSdeVeSchedulerState:
# setable values
timesteps: Optional[jnp.ndarray] = None
discrete_sigmas: Optional[jnp.ndarray] = None
sigmas: Optional[jnp.ndarray] = None
@classmethod
def create(cls):
return cls()
@dataclass
class FlaxSdeVeOutput(FlaxSchedulerOutput):
"""
Output class for the ScoreSdeVeScheduler's step function output.
Args:
state (`ScoreSdeVeSchedulerState`):
prev_sample (`jnp.ndarray` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
prev_sample_mean (`jnp.ndarray` of shape `(batch_size, num_channels, height, width)` for images):
Mean averaged `prev_sample`. Same as `prev_sample`, only mean-averaged over previous timesteps.
"""
state: ScoreSdeVeSchedulerState
prev_sample: jnp.ndarray
prev_sample_mean: Optional[jnp.ndarray] = None
class FlaxScoreSdeVeScheduler(FlaxSchedulerMixin, ConfigMixin):
"""
The variance exploding stochastic differential equation (SDE) scheduler.
For more information, see the original paper: https://arxiv.org/abs/2011.13456
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
snr (`float`):
coefficient weighting the step from the model_output sample (from the network) to the random noise.
sigma_min (`float`):
initial noise scale for sigma sequence in sampling procedure. The minimum sigma should mirror the
distribution of the data.
sigma_max (`float`): maximum value used for the range of continuous timesteps passed into the model.
sampling_eps (`float`): the end value of sampling, where timesteps decrease progressively from 1 to
epsilon.
correct_steps (`int`): number of correction steps performed on a produced sample.
"""
@property
def has_state(self):
return True
@register_to_config
def __init__(
self,
num_train_timesteps: int = 2000,
snr: float = 0.15,
sigma_min: float = 0.01,
sigma_max: float = 1348.0,
sampling_eps: float = 1e-5,
correct_steps: int = 1,
):
pass
def create_state(self):
state = ScoreSdeVeSchedulerState.create()
return self.set_sigmas(
state,
self.config.num_train_timesteps,
self.config.sigma_min,
self.config.sigma_max,
self.config.sampling_eps,
)
def set_timesteps(
self, state: ScoreSdeVeSchedulerState, num_inference_steps: int, shape: Tuple = (), sampling_eps: float = None
) -> ScoreSdeVeSchedulerState:
"""
Sets the continuous timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
state (`ScoreSdeVeSchedulerState`): the `FlaxScoreSdeVeScheduler` state data class instance.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
sampling_eps (`float`, optional):
final timestep value (overrides value given at Scheduler instantiation).
"""
sampling_eps = sampling_eps if sampling_eps is not None else self.config.sampling_eps
timesteps = jnp.linspace(1, sampling_eps, num_inference_steps)
return state.replace(timesteps=timesteps)
def set_sigmas(
self,
state: ScoreSdeVeSchedulerState,
num_inference_steps: int,
sigma_min: float = None,
sigma_max: float = None,
sampling_eps: float = None,
) -> ScoreSdeVeSchedulerState:
"""
Sets the noise scales used for the diffusion chain. Supporting function to be run before inference.
The sigmas control the weight of the `drift` and `diffusion` components of sample update.
Args:
state (`ScoreSdeVeSchedulerState`): the `FlaxScoreSdeVeScheduler` state data class instance.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
sigma_min (`float`, optional):
initial noise scale value (overrides value given at Scheduler instantiation).
sigma_max (`float`, optional):
final noise scale value (overrides value given at Scheduler instantiation).
sampling_eps (`float`, optional):
final timestep value (overrides value given at Scheduler instantiation).
"""
sigma_min = sigma_min if sigma_min is not None else self.config.sigma_min
sigma_max = sigma_max if sigma_max is not None else self.config.sigma_max
sampling_eps = sampling_eps if sampling_eps is not None else self.config.sampling_eps
if state.timesteps is None:
state = self.set_timesteps(state, num_inference_steps, sampling_eps)
discrete_sigmas = jnp.exp(jnp.linspace(jnp.log(sigma_min), jnp.log(sigma_max), num_inference_steps))
sigmas = jnp.array([sigma_min * (sigma_max / sigma_min) ** t for t in state.timesteps])
return state.replace(discrete_sigmas=discrete_sigmas, sigmas=sigmas)
def get_adjacent_sigma(self, state, timesteps, t):
return jnp.where(timesteps == 0, jnp.zeros_like(t), state.discrete_sigmas[timesteps - 1])
def step_pred(
self,
state: ScoreSdeVeSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
key: random.KeyArray,
return_dict: bool = True,
) -> Union[FlaxSdeVeOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
state (`ScoreSdeVeSchedulerState`): the `FlaxScoreSdeVeScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
generator: random number generator.
return_dict (`bool`): option for returning tuple rather than FlaxSdeVeOutput class
Returns:
[`FlaxSdeVeOutput`] or `tuple`: [`FlaxSdeVeOutput`] if `return_dict` is True, otherwise a `tuple`. When
returning a tuple, the first element is the sample tensor.
"""
if state.timesteps is None:
raise ValueError(
"`state.timesteps` is not set, you need to run 'set_timesteps' after creating the scheduler"
)
timestep = timestep * jnp.ones(
sample.shape[0],
)
timesteps = (timestep * (len(state.timesteps) - 1)).long()
sigma = state.discrete_sigmas[timesteps]
adjacent_sigma = self.get_adjacent_sigma(state, timesteps, timestep)
drift = jnp.zeros_like(sample)
diffusion = (sigma**2 - adjacent_sigma**2) ** 0.5
# equation 6 in the paper: the model_output modeled by the network is grad_x log pt(x)
# also equation 47 shows the analog from SDE models to ancestral sampling methods
diffusion = diffusion.flatten()
diffusion = broadcast_to_shape_from_left(diffusion, sample.shape)
drift = drift - diffusion**2 * model_output
# equation 6: sample noise for the diffusion term of
key = random.split(key, num=1)
noise = random.normal(key=key, shape=sample.shape)
prev_sample_mean = sample - drift # subtract because `dt` is a small negative timestep
# TODO is the variable diffusion the correct scaling term for the noise?
prev_sample = prev_sample_mean + diffusion * noise # add impact of diffusion field g
if not return_dict:
return (prev_sample, prev_sample_mean, state)
return FlaxSdeVeOutput(prev_sample=prev_sample, prev_sample_mean=prev_sample_mean, state=state)
def step_correct(
self,
state: ScoreSdeVeSchedulerState,
model_output: jnp.ndarray,
sample: jnp.ndarray,
key: random.KeyArray,
return_dict: bool = True,
) -> Union[FlaxSdeVeOutput, Tuple]:
"""
Correct the predicted sample based on the output model_output of the network. This is often run repeatedly
after making the prediction for the previous timestep.
Args:
state (`ScoreSdeVeSchedulerState`): the `FlaxScoreSdeVeScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
generator: random number generator.
return_dict (`bool`): option for returning tuple rather than FlaxSdeVeOutput class
Returns:
[`FlaxSdeVeOutput`] or `tuple`: [`FlaxSdeVeOutput`] if `return_dict` is True, otherwise a `tuple`. When
returning a tuple, the first element is the sample tensor.
"""
if state.timesteps is None:
raise ValueError(
"`state.timesteps` is not set, you need to run 'set_timesteps' after creating the scheduler"
)
# For small batch sizes, the paper "suggest replacing norm(z) with sqrt(d), where d is the dim. of z"
# sample noise for correction
key = random.split(key, num=1)
noise = random.normal(key=key, shape=sample.shape)
# compute step size from the model_output, the noise, and the snr
grad_norm = jnp.linalg.norm(model_output)
noise_norm = jnp.linalg.norm(noise)
step_size = (self.config.snr * noise_norm / grad_norm) ** 2 * 2
step_size = step_size * jnp.ones(sample.shape[0])
# compute corrected sample: model_output term and noise term
step_size = step_size.flatten()
step_size = broadcast_to_shape_from_left(step_size, sample.shape)
prev_sample_mean = sample + step_size * model_output
prev_sample = prev_sample_mean + ((step_size * 2) ** 0.5) * noise
if not return_dict:
return (prev_sample, state)
return FlaxSdeVeOutput(prev_sample=prev_sample, state=state)
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_sde_ve_flax.py |
# Copyright 2023 Katherine Crowson and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import flax
import jax.numpy as jnp
from scipy import integrate
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils_flax import (
CommonSchedulerState,
FlaxKarrasDiffusionSchedulers,
FlaxSchedulerMixin,
FlaxSchedulerOutput,
broadcast_to_shape_from_left,
)
@flax.struct.dataclass
class LMSDiscreteSchedulerState:
common: CommonSchedulerState
# setable values
init_noise_sigma: jnp.ndarray
timesteps: jnp.ndarray
sigmas: jnp.ndarray
num_inference_steps: Optional[int] = None
# running values
derivatives: Optional[jnp.ndarray] = None
@classmethod
def create(
cls, common: CommonSchedulerState, init_noise_sigma: jnp.ndarray, timesteps: jnp.ndarray, sigmas: jnp.ndarray
):
return cls(common=common, init_noise_sigma=init_noise_sigma, timesteps=timesteps, sigmas=sigmas)
@dataclass
class FlaxLMSSchedulerOutput(FlaxSchedulerOutput):
state: LMSDiscreteSchedulerState
class FlaxLMSDiscreteScheduler(FlaxSchedulerMixin, ConfigMixin):
"""
Linear Multistep Scheduler for discrete beta schedules. Based on the original k-diffusion implementation by
Katherine Crowson:
https://github.com/crowsonkb/k-diffusion/blob/481677d114f6ea445aa009cf5bd7a9cdee909e47/k_diffusion/sampling.py#L181
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
beta_start (`float`): the starting `beta` value of inference.
beta_end (`float`): the final `beta` value.
beta_schedule (`str`):
the beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`jnp.ndarray`, optional):
option to pass an array of betas directly to the constructor to bypass `beta_start`, `beta_end` etc.
prediction_type (`str`, default `epsilon`, optional):
prediction type of the scheduler function, one of `epsilon` (predicting the noise of the diffusion
process), `sample` (directly predicting the noisy sample`) or `v_prediction` (see section 2.4
https://imagen.research.google/video/paper.pdf)
dtype (`jnp.dtype`, *optional*, defaults to `jnp.float32`):
the `dtype` used for params and computation.
"""
_compatibles = [e.name for e in FlaxKarrasDiffusionSchedulers]
dtype: jnp.dtype
@property
def has_state(self):
return True
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[jnp.ndarray] = None,
prediction_type: str = "epsilon",
dtype: jnp.dtype = jnp.float32,
):
self.dtype = dtype
def create_state(self, common: Optional[CommonSchedulerState] = None) -> LMSDiscreteSchedulerState:
if common is None:
common = CommonSchedulerState.create(self)
timesteps = jnp.arange(0, self.config.num_train_timesteps).round()[::-1]
sigmas = ((1 - common.alphas_cumprod) / common.alphas_cumprod) ** 0.5
# standard deviation of the initial noise distribution
init_noise_sigma = sigmas.max()
return LMSDiscreteSchedulerState.create(
common=common,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
sigmas=sigmas,
)
def scale_model_input(self, state: LMSDiscreteSchedulerState, sample: jnp.ndarray, timestep: int) -> jnp.ndarray:
"""
Scales the denoising model input by `(sigma**2 + 1) ** 0.5` to match the K-LMS algorithm.
Args:
state (`LMSDiscreteSchedulerState`):
the `FlaxLMSDiscreteScheduler` state data class instance.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
timestep (`int`):
current discrete timestep in the diffusion chain.
Returns:
`jnp.ndarray`: scaled input sample
"""
(step_index,) = jnp.where(state.timesteps == timestep, size=1)
step_index = step_index[0]
sigma = state.sigmas[step_index]
sample = sample / ((sigma**2 + 1) ** 0.5)
return sample
def get_lms_coefficient(self, state: LMSDiscreteSchedulerState, order, t, current_order):
"""
Compute a linear multistep coefficient.
Args:
order (TODO):
t (TODO):
current_order (TODO):
"""
def lms_derivative(tau):
prod = 1.0
for k in range(order):
if current_order == k:
continue
prod *= (tau - state.sigmas[t - k]) / (state.sigmas[t - current_order] - state.sigmas[t - k])
return prod
integrated_coeff = integrate.quad(lms_derivative, state.sigmas[t], state.sigmas[t + 1], epsrel=1e-4)[0]
return integrated_coeff
def set_timesteps(
self, state: LMSDiscreteSchedulerState, num_inference_steps: int, shape: Tuple = ()
) -> LMSDiscreteSchedulerState:
"""
Sets the timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
state (`LMSDiscreteSchedulerState`):
the `FlaxLMSDiscreteScheduler` state data class instance.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
"""
timesteps = jnp.linspace(self.config.num_train_timesteps - 1, 0, num_inference_steps, dtype=self.dtype)
low_idx = jnp.floor(timesteps).astype(jnp.int32)
high_idx = jnp.ceil(timesteps).astype(jnp.int32)
frac = jnp.mod(timesteps, 1.0)
sigmas = ((1 - state.common.alphas_cumprod) / state.common.alphas_cumprod) ** 0.5
sigmas = (1 - frac) * sigmas[low_idx] + frac * sigmas[high_idx]
sigmas = jnp.concatenate([sigmas, jnp.array([0.0], dtype=self.dtype)])
timesteps = timesteps.astype(jnp.int32)
# initial running values
derivatives = jnp.zeros((0,) + shape, dtype=self.dtype)
return state.replace(
timesteps=timesteps,
sigmas=sigmas,
num_inference_steps=num_inference_steps,
derivatives=derivatives,
)
def step(
self,
state: LMSDiscreteSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
order: int = 4,
return_dict: bool = True,
) -> Union[FlaxLMSSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
state (`LMSDiscreteSchedulerState`): the `FlaxLMSDiscreteScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
order: coefficient for multi-step inference.
return_dict (`bool`): option for returning tuple rather than FlaxLMSSchedulerOutput class
Returns:
[`FlaxLMSSchedulerOutput`] or `tuple`: [`FlaxLMSSchedulerOutput`] if `return_dict` is True, otherwise a
`tuple`. When returning a tuple, the first element is the sample tensor.
"""
if state.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
sigma = state.sigmas[timestep]
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
if self.config.prediction_type == "epsilon":
pred_original_sample = sample - sigma * model_output
elif self.config.prediction_type == "v_prediction":
# * c_out + input * c_skip
pred_original_sample = model_output * (-sigma / (sigma**2 + 1) ** 0.5) + (sample / (sigma**2 + 1))
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
# 2. Convert to an ODE derivative
derivative = (sample - pred_original_sample) / sigma
state = state.replace(derivatives=jnp.append(state.derivatives, derivative))
if len(state.derivatives) > order:
state = state.replace(derivatives=jnp.delete(state.derivatives, 0))
# 3. Compute linear multistep coefficients
order = min(timestep + 1, order)
lms_coeffs = [self.get_lms_coefficient(state, order, timestep, curr_order) for curr_order in range(order)]
# 4. Compute previous sample based on the derivatives path
prev_sample = sample + sum(
coeff * derivative for coeff, derivative in zip(lms_coeffs, reversed(state.derivatives))
)
if not return_dict:
return (prev_sample, state)
return FlaxLMSSchedulerOutput(prev_sample=prev_sample, state=state)
def add_noise(
self,
state: LMSDiscreteSchedulerState,
original_samples: jnp.ndarray,
noise: jnp.ndarray,
timesteps: jnp.ndarray,
) -> jnp.ndarray:
sigma = state.sigmas[timesteps].flatten()
sigma = broadcast_to_shape_from_left(sigma, noise.shape)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_lms_discrete_flax.py |
# Copyright 2023 TSAIL Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/LuChengTHU/dpm-solver
import math
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DPMSolverMultistepInverseScheduler(SchedulerMixin, ConfigMixin):
"""
`DPMSolverMultistepInverseScheduler` is the reverse scheduler of [`DPMSolverMultistepScheduler`].
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
solver_order (`int`, defaults to 2):
The DPMSolver order which can be `1` or `2` or `3`. It is recommended to use `solver_order=2` for guided
sampling, and `solver_order=3` for unconditional sampling.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
thresholding (`bool`, defaults to `False`):
Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
as Stable Diffusion.
dynamic_thresholding_ratio (`float`, defaults to 0.995):
The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
sample_max_value (`float`, defaults to 1.0):
The threshold value for dynamic thresholding. Valid only when `thresholding=True` and
`algorithm_type="dpmsolver++"`.
algorithm_type (`str`, defaults to `dpmsolver++`):
Algorithm type for the solver; can be `dpmsolver`, `dpmsolver++`, `sde-dpmsolver` or `sde-dpmsolver++`. The
`dpmsolver` type implements the algorithms in the [DPMSolver](https://huggingface.co/papers/2206.00927)
paper, and the `dpmsolver++` type implements the algorithms in the
[DPMSolver++](https://huggingface.co/papers/2211.01095) paper. It is recommended to use `dpmsolver++` or
`sde-dpmsolver++` with `solver_order=2` for guided sampling like in Stable Diffusion.
solver_type (`str`, defaults to `midpoint`):
Solver type for the second-order solver; can be `midpoint` or `heun`. The solver type slightly affects the
sample quality, especially for a small number of steps. It is recommended to use `midpoint` solvers.
lower_order_final (`bool`, defaults to `True`):
Whether to use lower-order solvers in the final steps. Only valid for < 15 inference steps. This can
stabilize the sampling of DPMSolver for steps < 15, especially for steps <= 10.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
lambda_min_clipped (`float`, defaults to `-inf`):
Clipping threshold for the minimum value of `lambda(t)` for numerical stability. This is critical for the
cosine (`squaredcos_cap_v2`) noise schedule.
variance_type (`str`, *optional*):
Set to "learned" or "learned_range" for diffusion models that predict variance. If set, the model's output
contains the predicted Gaussian variance.
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
solver_order: int = 2,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
sample_max_value: float = 1.0,
algorithm_type: str = "dpmsolver++",
solver_type: str = "midpoint",
lower_order_final: bool = True,
use_karras_sigmas: Optional[bool] = False,
lambda_min_clipped: float = -float("inf"),
variance_type: Optional[str] = None,
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# Currently we only support VP-type noise schedule
self.alpha_t = torch.sqrt(self.alphas_cumprod)
self.sigma_t = torch.sqrt(1 - self.alphas_cumprod)
self.lambda_t = torch.log(self.alpha_t) - torch.log(self.sigma_t)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# settings for DPM-Solver
if algorithm_type not in ["dpmsolver", "dpmsolver++", "sde-dpmsolver", "sde-dpmsolver++"]:
if algorithm_type == "deis":
self.register_to_config(algorithm_type="dpmsolver++")
else:
raise NotImplementedError(f"{algorithm_type} does is not implemented for {self.__class__}")
if solver_type not in ["midpoint", "heun"]:
if solver_type in ["logrho", "bh1", "bh2"]:
self.register_to_config(solver_type="midpoint")
else:
raise NotImplementedError(f"{solver_type} does is not implemented for {self.__class__}")
# setable values
self.num_inference_steps = None
timesteps = np.linspace(0, num_train_timesteps - 1, num_train_timesteps, dtype=np.float32).copy()
self.timesteps = torch.from_numpy(timesteps)
self.model_outputs = [None] * solver_order
self.lower_order_nums = 0
self.use_karras_sigmas = use_karras_sigmas
def set_timesteps(self, num_inference_steps: int = None, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
# Clipping the minimum of all lambda(t) for numerical stability.
# This is critical for cosine (squaredcos_cap_v2) noise schedule.
clipped_idx = torch.searchsorted(torch.flip(self.lambda_t, [0]), self.lambda_min_clipped).item()
self.noisiest_timestep = self.config.num_train_timesteps - 1 - clipped_idx
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, self.noisiest_timestep, num_inference_steps + 1).round()[:-1].copy().astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = (self.noisiest_timestep + 1) // (num_inference_steps + 1)
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps + 1) * step_ratio).round()[:-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.arange(self.noisiest_timestep + 1, 0, -step_ratio).round()[::-1].copy().astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', "
"'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
if self.config.use_karras_sigmas:
log_sigmas = np.log(sigmas)
sigmas = self._convert_to_karras(in_sigmas=sigmas, num_inference_steps=num_inference_steps)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas]).round()
timesteps = timesteps.copy().astype(np.int64)
self.sigmas = torch.from_numpy(sigmas)
# when num_inference_steps == num_train_timesteps, we can end up with
# duplicates in timesteps.
_, unique_indices = np.unique(timesteps, return_index=True)
timesteps = timesteps[np.sort(unique_indices)]
self.timesteps = torch.from_numpy(timesteps).to(device)
self.num_inference_steps = len(timesteps)
self.model_outputs = [
None,
] * self.config.solver_order
self.lower_order_nums = 0
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._sigma_to_t
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._convert_to_karras
def _convert_to_karras(self, in_sigmas: torch.FloatTensor, num_inference_steps) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
# Copied from diffusers.schedulers.scheduling_dpmsolver_multistep.DPMSolverMultistepScheduler.convert_model_output
def convert_model_output(
self, model_output: torch.FloatTensor, timestep: int, sample: torch.FloatTensor
) -> torch.FloatTensor:
"""
Convert the model output to the corresponding type the DPMSolver/DPMSolver++ algorithm needs. DPM-Solver is
designed to discretize an integral of the noise prediction model, and DPM-Solver++ is designed to discretize an
integral of the data prediction model.
<Tip>
The algorithm and model type are decoupled. You can use either DPMSolver or DPMSolver++ for both noise
prediction and data prediction models.
</Tip>
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The converted model output.
"""
# DPM-Solver++ needs to solve an integral of the data prediction model.
if self.config.algorithm_type in ["dpmsolver++", "sde-dpmsolver++"]:
if self.config.prediction_type == "epsilon":
# DPM-Solver and DPM-Solver++ only need the "mean" output.
if self.config.variance_type in ["learned", "learned_range"]:
model_output = model_output[:, :3]
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = (sample - sigma_t * model_output) / alpha_t
elif self.config.prediction_type == "sample":
x0_pred = model_output
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = alpha_t * sample - sigma_t * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the DPMSolverMultistepScheduler."
)
if self.config.thresholding:
x0_pred = self._threshold_sample(x0_pred)
return x0_pred
# DPM-Solver needs to solve an integral of the noise prediction model.
elif self.config.algorithm_type in ["dpmsolver", "sde-dpmsolver"]:
if self.config.prediction_type == "epsilon":
# DPM-Solver and DPM-Solver++ only need the "mean" output.
if self.config.variance_type in ["learned", "learned_range"]:
epsilon = model_output[:, :3]
else:
epsilon = model_output
elif self.config.prediction_type == "sample":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = (sample - alpha_t * model_output) / sigma_t
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = alpha_t * model_output + sigma_t * sample
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the DPMSolverMultistepScheduler."
)
if self.config.thresholding:
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = (sample - sigma_t * epsilon) / alpha_t
x0_pred = self._threshold_sample(x0_pred)
epsilon = (sample - alpha_t * x0_pred) / sigma_t
return epsilon
def dpm_solver_first_order_update(
self,
model_output: torch.FloatTensor,
timestep: int,
prev_timestep: int,
sample: torch.FloatTensor,
noise: Optional[torch.FloatTensor] = None,
) -> torch.FloatTensor:
"""
One step for the first-order DPMSolver (equivalent to DDIM).
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
lambda_t, lambda_s = self.lambda_t[prev_timestep], self.lambda_t[timestep]
alpha_t, alpha_s = self.alpha_t[prev_timestep], self.alpha_t[timestep]
sigma_t, sigma_s = self.sigma_t[prev_timestep], self.sigma_t[timestep]
h = lambda_t - lambda_s
if self.config.algorithm_type == "dpmsolver++":
x_t = (sigma_t / sigma_s) * sample - (alpha_t * (torch.exp(-h) - 1.0)) * model_output
elif self.config.algorithm_type == "dpmsolver":
x_t = (alpha_t / alpha_s) * sample - (sigma_t * (torch.exp(h) - 1.0)) * model_output
elif "sde" in self.config.algorithm_type:
raise NotImplementedError(
f"Inversion step is not yet implemented for algorithm type {self.config.algorithm_type}."
)
return x_t
def multistep_dpm_solver_second_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
noise: Optional[torch.FloatTensor] = None,
) -> torch.FloatTensor:
"""
One step for the second-order multistep DPMSolver.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1 = prev_timestep, timestep_list[-1], timestep_list[-2]
m0, m1 = model_output_list[-1], model_output_list[-2]
lambda_t, lambda_s0, lambda_s1 = self.lambda_t[t], self.lambda_t[s0], self.lambda_t[s1]
alpha_t, alpha_s0 = self.alpha_t[t], self.alpha_t[s0]
sigma_t, sigma_s0 = self.sigma_t[t], self.sigma_t[s0]
h, h_0 = lambda_t - lambda_s0, lambda_s0 - lambda_s1
r0 = h_0 / h
D0, D1 = m0, (1.0 / r0) * (m0 - m1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2211.01095 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
- 0.5 * (alpha_t * (torch.exp(-h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
+ (alpha_t * ((torch.exp(-h) - 1.0) / h + 1.0)) * D1
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- 0.5 * (sigma_t * (torch.exp(h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1
)
elif "sde" in self.config.algorithm_type:
raise NotImplementedError(
f"Inversion step is not yet implemented for algorithm type {self.config.algorithm_type}."
)
return x_t
# Copied from diffusers.schedulers.scheduling_dpmsolver_multistep.DPMSolverMultistepScheduler.multistep_dpm_solver_third_order_update
def multistep_dpm_solver_third_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the third-order multistep DPMSolver.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1, s2 = prev_timestep, timestep_list[-1], timestep_list[-2], timestep_list[-3]
m0, m1, m2 = model_output_list[-1], model_output_list[-2], model_output_list[-3]
lambda_t, lambda_s0, lambda_s1, lambda_s2 = (
self.lambda_t[t],
self.lambda_t[s0],
self.lambda_t[s1],
self.lambda_t[s2],
)
alpha_t, alpha_s0 = self.alpha_t[t], self.alpha_t[s0]
sigma_t, sigma_s0 = self.sigma_t[t], self.sigma_t[s0]
h, h_0, h_1 = lambda_t - lambda_s0, lambda_s0 - lambda_s1, lambda_s1 - lambda_s2
r0, r1 = h_0 / h, h_1 / h
D0 = m0
D1_0, D1_1 = (1.0 / r0) * (m0 - m1), (1.0 / r1) * (m1 - m2)
D1 = D1_0 + (r0 / (r0 + r1)) * (D1_0 - D1_1)
D2 = (1.0 / (r0 + r1)) * (D1_0 - D1_1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
+ (alpha_t * ((torch.exp(-h) - 1.0) / h + 1.0)) * D1
- (alpha_t * ((torch.exp(-h) - 1.0 + h) / h**2 - 0.5)) * D2
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1
- (sigma_t * ((torch.exp(h) - 1.0 - h) / h**2 - 0.5)) * D2
)
return x_t
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
generator=None,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the multistep DPMSolver.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
step_index = (self.timesteps == timestep).nonzero()
if len(step_index) == 0:
step_index = len(self.timesteps) - 1
else:
step_index = step_index.item()
prev_timestep = (
self.noisiest_timestep if step_index == len(self.timesteps) - 1 else self.timesteps[step_index + 1]
)
lower_order_final = (
(step_index == len(self.timesteps) - 1) and self.config.lower_order_final and len(self.timesteps) < 15
)
lower_order_second = (
(step_index == len(self.timesteps) - 2) and self.config.lower_order_final and len(self.timesteps) < 15
)
model_output = self.convert_model_output(model_output, timestep, sample)
for i in range(self.config.solver_order - 1):
self.model_outputs[i] = self.model_outputs[i + 1]
self.model_outputs[-1] = model_output
if self.config.algorithm_type in ["sde-dpmsolver", "sde-dpmsolver++"]:
noise = randn_tensor(
model_output.shape, generator=generator, device=model_output.device, dtype=model_output.dtype
)
else:
noise = None
if self.config.solver_order == 1 or self.lower_order_nums < 1 or lower_order_final:
prev_sample = self.dpm_solver_first_order_update(
model_output, timestep, prev_timestep, sample, noise=noise
)
elif self.config.solver_order == 2 or self.lower_order_nums < 2 or lower_order_second:
timestep_list = [self.timesteps[step_index - 1], timestep]
prev_sample = self.multistep_dpm_solver_second_order_update(
self.model_outputs, timestep_list, prev_timestep, sample, noise=noise
)
else:
timestep_list = [self.timesteps[step_index - 2], self.timesteps[step_index - 1], timestep]
prev_sample = self.multistep_dpm_solver_third_order_update(
self.model_outputs, timestep_list, prev_timestep, sample
)
if self.lower_order_nums < self.config.solver_order:
self.lower_order_nums += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
# Copied from diffusers.schedulers.scheduling_dpmsolver_multistep.DPMSolverMultistepScheduler.scale_model_input
def scale_model_input(self, sample: torch.FloatTensor, *args, **kwargs) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_dpmsolver_multistep_inverse.py |
# Copyright 2023 Katherine Crowson, The HuggingFace Team and hlky. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from collections import defaultdict
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class KDPM2AncestralDiscreteScheduler(SchedulerMixin, ConfigMixin):
"""
KDPM2DiscreteScheduler with ancestral sampling is inspired by the DPMSolver2 and Algorithm 2 from the [Elucidating
the Design Space of Diffusion-Based Generative Models](https://huggingface.co/papers/2206.00364) paper.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.00085):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.012):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 2
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.00085, # sensible defaults
beta_end: float = 0.012,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
prediction_type: str = "epsilon",
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# set all values
self.set_timesteps(num_train_timesteps, None, num_train_timesteps)
self._step_index = None
# Copied from diffusers.schedulers.scheduling_heun_discrete.HeunDiscreteScheduler.index_for_timestep
def index_for_timestep(self, timestep, schedule_timesteps=None):
if schedule_timesteps is None:
schedule_timesteps = self.timesteps
indices = (schedule_timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(self._index_counter) == 0:
pos = 1 if len(indices) > 1 else 0
else:
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
pos = self._index_counter[timestep_int]
return indices[pos].item()
@property
def init_noise_sigma(self):
# standard deviation of the initial noise distribution
if self.config.timestep_spacing in ["linspace", "trailing"]:
return self.sigmas.max()
return (self.sigmas.max() ** 2 + 1) ** 0.5
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self,
sample: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
if self.step_index is None:
self._init_step_index(timestep)
if self.state_in_first_order:
sigma = self.sigmas[self.step_index]
else:
sigma = self.sigmas_interpol[self.step_index - 1]
sample = sample / ((sigma**2 + 1) ** 0.5)
return sample
def set_timesteps(
self,
num_inference_steps: int,
device: Union[str, torch.device] = None,
num_train_timesteps: Optional[int] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
num_train_timesteps = num_train_timesteps or self.config.num_train_timesteps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = np.linspace(0, num_train_timesteps - 1, num_inference_steps, dtype=np.float32)[::-1].copy()
elif self.config.timestep_spacing == "leading":
step_ratio = num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.float32)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(num_train_timesteps, 0, -step_ratio)).round().copy().astype(np.float32)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
self.log_sigmas = torch.from_numpy(np.log(sigmas)).to(device)
sigmas = np.interp(timesteps, np.arange(0, len(sigmas)), sigmas)
sigmas = np.concatenate([sigmas, [0.0]]).astype(np.float32)
sigmas = torch.from_numpy(sigmas).to(device=device)
# compute up and down sigmas
sigmas_next = sigmas.roll(-1)
sigmas_next[-1] = 0.0
sigmas_up = (sigmas_next**2 * (sigmas**2 - sigmas_next**2) / sigmas**2) ** 0.5
sigmas_down = (sigmas_next**2 - sigmas_up**2) ** 0.5
sigmas_down[-1] = 0.0
# compute interpolated sigmas
sigmas_interpol = sigmas.log().lerp(sigmas_down.log(), 0.5).exp()
sigmas_interpol[-2:] = 0.0
# set sigmas
self.sigmas = torch.cat([sigmas[:1], sigmas[1:].repeat_interleave(2), sigmas[-1:]])
self.sigmas_interpol = torch.cat(
[sigmas_interpol[:1], sigmas_interpol[1:].repeat_interleave(2), sigmas_interpol[-1:]]
)
self.sigmas_up = torch.cat([sigmas_up[:1], sigmas_up[1:].repeat_interleave(2), sigmas_up[-1:]])
self.sigmas_down = torch.cat([sigmas_down[:1], sigmas_down[1:].repeat_interleave(2), sigmas_down[-1:]])
timesteps = torch.from_numpy(timesteps).to(device)
timesteps_interpol = self.sigma_to_t(sigmas_interpol).to(device, dtype=timesteps.dtype)
interleaved_timesteps = torch.stack((timesteps_interpol[:-2, None], timesteps[1:, None]), dim=-1).flatten()
self.timesteps = torch.cat([timesteps[:1], interleaved_timesteps])
self.sample = None
# for exp beta schedules, such as the one for `pipeline_shap_e.py`
# we need an index counter
self._index_counter = defaultdict(int)
self._step_index = None
def sigma_to_t(self, sigma):
# get log sigma
log_sigma = sigma.log()
# get distribution
dists = log_sigma - self.log_sigmas[:, None]
# get sigmas range
low_idx = dists.ge(0).cumsum(dim=0).argmax(dim=0).clamp(max=self.log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = self.log_sigmas[low_idx]
high = self.log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = w.clamp(0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.view(sigma.shape)
return t
@property
def state_in_first_order(self):
return self.sample is None
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
def step(
self,
model_output: Union[torch.FloatTensor, np.ndarray],
timestep: Union[float, torch.FloatTensor],
sample: Union[torch.FloatTensor, np.ndarray],
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_ddim.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.step_index is None:
self._init_step_index(timestep)
# advance index counter by 1
timestep_int = timestep.cpu().item() if torch.is_tensor(timestep) else timestep
self._index_counter[timestep_int] += 1
if self.state_in_first_order:
sigma = self.sigmas[self.step_index]
sigma_interpol = self.sigmas_interpol[self.step_index]
sigma_up = self.sigmas_up[self.step_index]
sigma_down = self.sigmas_down[self.step_index - 1]
else:
# 2nd order / KPDM2's method
sigma = self.sigmas[self.step_index - 1]
sigma_interpol = self.sigmas_interpol[self.step_index - 1]
sigma_up = self.sigmas_up[self.step_index - 1]
sigma_down = self.sigmas_down[self.step_index - 1]
# currently only gamma=0 is supported. This usually works best anyways.
# We can support gamma in the future but then need to scale the timestep before
# passing it to the model which requires a change in API
gamma = 0
sigma_hat = sigma * (gamma + 1) # Note: sigma_hat == sigma for now
device = model_output.device
noise = randn_tensor(model_output.shape, dtype=model_output.dtype, device=device, generator=generator)
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
if self.config.prediction_type == "epsilon":
sigma_input = sigma_hat if self.state_in_first_order else sigma_interpol
pred_original_sample = sample - sigma_input * model_output
elif self.config.prediction_type == "v_prediction":
sigma_input = sigma_hat if self.state_in_first_order else sigma_interpol
pred_original_sample = model_output * (-sigma_input / (sigma_input**2 + 1) ** 0.5) + (
sample / (sigma_input**2 + 1)
)
elif self.config.prediction_type == "sample":
raise NotImplementedError("prediction_type not implemented yet: sample")
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
if self.state_in_first_order:
# 2. Convert to an ODE derivative for 1st order
derivative = (sample - pred_original_sample) / sigma_hat
# 3. delta timestep
dt = sigma_interpol - sigma_hat
# store for 2nd order step
self.sample = sample
self.dt = dt
prev_sample = sample + derivative * dt
else:
# DPM-Solver-2
# 2. Convert to an ODE derivative for 2nd order
derivative = (sample - pred_original_sample) / sigma_interpol
# 3. delta timestep
dt = sigma_down - sigma_hat
sample = self.sample
self.sample = None
prev_sample = sample + derivative * dt
prev_sample = prev_sample + noise * sigma_up
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
# Copied from diffusers.schedulers.scheduling_heun_discrete.HeunDiscreteScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [self.index_for_timestep(t, schedule_timesteps) for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_k_dpm_2_ancestral_discrete.py |
# Copyright 2023 Katherine Crowson and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
import warnings
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from scipy import integrate
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput with DDPM->LMSDiscrete
class LMSDiscreteSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class LMSDiscreteScheduler(SchedulerMixin, ConfigMixin):
"""
A linear multistep scheduler for discrete beta schedules.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
use_karras_sigmas: Optional[bool] = False,
prediction_type: str = "epsilon",
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
sigmas = np.concatenate([sigmas[::-1], [0.0]]).astype(np.float32)
self.sigmas = torch.from_numpy(sigmas)
# setable values
self.num_inference_steps = None
self.use_karras_sigmas = use_karras_sigmas
self.set_timesteps(num_train_timesteps, None)
self.derivatives = []
self.is_scale_input_called = False
self._step_index = None
@property
def init_noise_sigma(self):
# standard deviation of the initial noise distribution
if self.config.timestep_spacing in ["linspace", "trailing"]:
return self.sigmas.max()
return (self.sigmas.max() ** 2 + 1) ** 0.5
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self, sample: torch.FloatTensor, timestep: Union[float, torch.FloatTensor]
) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`float` or `torch.FloatTensor`):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
sample = sample / ((sigma**2 + 1) ** 0.5)
self.is_scale_input_called = True
return sample
def get_lms_coefficient(self, order, t, current_order):
"""
Compute the linear multistep coefficient.
Args:
order ():
t ():
current_order ():
"""
def lms_derivative(tau):
prod = 1.0
for k in range(order):
if current_order == k:
continue
prod *= (tau - self.sigmas[t - k]) / (self.sigmas[t - current_order] - self.sigmas[t - k])
return prod
integrated_coeff = integrate.quad(lms_derivative, self.sigmas[t], self.sigmas[t + 1], epsrel=1e-4)[0]
return integrated_coeff
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps, dtype=np.float32)[
::-1
].copy()
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.float32)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(self.config.num_train_timesteps, 0, -step_ratio)).round().copy().astype(np.float32)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
log_sigmas = np.log(sigmas)
sigmas = np.interp(timesteps, np.arange(0, len(sigmas)), sigmas)
if self.use_karras_sigmas:
sigmas = self._convert_to_karras(in_sigmas=sigmas)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas])
sigmas = np.concatenate([sigmas, [0.0]]).astype(np.float32)
self.sigmas = torch.from_numpy(sigmas).to(device=device)
self.timesteps = torch.from_numpy(timesteps).to(device=device)
self._step_index = None
self.derivatives = []
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
# copied from diffusers.schedulers.scheduling_euler_discrete._sigma_to_t
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# copied from diffusers.schedulers.scheduling_euler_discrete._convert_to_karras
def _convert_to_karras(self, in_sigmas: torch.FloatTensor) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, self.num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
def step(
self,
model_output: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
sample: torch.FloatTensor,
order: int = 4,
return_dict: bool = True,
) -> Union[LMSDiscreteSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float` or `torch.FloatTensor`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
order (`int`, defaults to 4):
The order of the linear multistep method.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if not self.is_scale_input_called:
warnings.warn(
"The `scale_model_input` function should be called before `step` to ensure correct denoising. "
"See `StableDiffusionPipeline` for a usage example."
)
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
if self.config.prediction_type == "epsilon":
pred_original_sample = sample - sigma * model_output
elif self.config.prediction_type == "v_prediction":
# * c_out + input * c_skip
pred_original_sample = model_output * (-sigma / (sigma**2 + 1) ** 0.5) + (sample / (sigma**2 + 1))
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
# 2. Convert to an ODE derivative
derivative = (sample - pred_original_sample) / sigma
self.derivatives.append(derivative)
if len(self.derivatives) > order:
self.derivatives.pop(0)
# 3. Compute linear multistep coefficients
order = min(self.step_index + 1, order)
lms_coeffs = [self.get_lms_coefficient(order, self.step_index, curr_order) for curr_order in range(order)]
# 4. Compute previous sample based on the derivatives path
prev_sample = sample + sum(
coeff * derivative for coeff, derivative in zip(lms_coeffs, reversed(self.derivatives))
)
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return LMSDiscreteSchedulerOutput(prev_sample=prev_sample, pred_original_sample=pred_original_sample)
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [(schedule_timesteps == t).nonzero().item() for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_lms_discrete.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput, logging
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import SchedulerMixin
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
@dataclass
class CMStochasticIterativeSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
"""
prev_sample: torch.FloatTensor
class CMStochasticIterativeScheduler(SchedulerMixin, ConfigMixin):
"""
Multistep and onestep sampling for consistency models.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 40):
The number of diffusion steps to train the model.
sigma_min (`float`, defaults to 0.002):
Minimum noise magnitude in the sigma schedule. Defaults to 0.002 from the original implementation.
sigma_max (`float`, defaults to 80.0):
Maximum noise magnitude in the sigma schedule. Defaults to 80.0 from the original implementation.
sigma_data (`float`, defaults to 0.5):
The standard deviation of the data distribution from the EDM
[paper](https://huggingface.co/papers/2206.00364). Defaults to 0.5 from the original implementation.
s_noise (`float`, defaults to 1.0):
The amount of additional noise to counteract loss of detail during sampling. A reasonable range is [1.000,
1.011]. Defaults to 1.0 from the original implementation.
rho (`float`, defaults to 7.0):
The parameter for calculating the Karras sigma schedule from the EDM
[paper](https://huggingface.co/papers/2206.00364). Defaults to 7.0 from the original implementation.
clip_denoised (`bool`, defaults to `True`):
Whether to clip the denoised outputs to `(-1, 1)`.
timesteps (`List` or `np.ndarray` or `torch.Tensor`, *optional*):
An explicit timestep schedule that can be optionally specified. The timesteps are expected to be in
increasing order.
"""
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 40,
sigma_min: float = 0.002,
sigma_max: float = 80.0,
sigma_data: float = 0.5,
s_noise: float = 1.0,
rho: float = 7.0,
clip_denoised: bool = True,
):
# standard deviation of the initial noise distribution
self.init_noise_sigma = sigma_max
ramp = np.linspace(0, 1, num_train_timesteps)
sigmas = self._convert_to_karras(ramp)
timesteps = self.sigma_to_t(sigmas)
# setable values
self.num_inference_steps = None
self.sigmas = torch.from_numpy(sigmas)
self.timesteps = torch.from_numpy(timesteps)
self.custom_timesteps = False
self.is_scale_input_called = False
self._step_index = None
def index_for_timestep(self, timestep, schedule_timesteps=None):
if schedule_timesteps is None:
schedule_timesteps = self.timesteps
indices = (schedule_timesteps == timestep).nonzero()
return indices.item()
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self, sample: torch.FloatTensor, timestep: Union[float, torch.FloatTensor]
) -> torch.FloatTensor:
"""
Scales the consistency model input by `(sigma**2 + sigma_data**2) ** 0.5`.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`float` or `torch.FloatTensor`):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
# Get sigma corresponding to timestep
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
sample = sample / ((sigma**2 + self.config.sigma_data**2) ** 0.5)
self.is_scale_input_called = True
return sample
def sigma_to_t(self, sigmas: Union[float, np.ndarray]):
"""
Gets scaled timesteps from the Karras sigmas for input to the consistency model.
Args:
sigmas (`float` or `np.ndarray`):
A single Karras sigma or an array of Karras sigmas.
Returns:
`float` or `np.ndarray`:
A scaled input timestep or scaled input timestep array.
"""
if not isinstance(sigmas, np.ndarray):
sigmas = np.array(sigmas, dtype=np.float64)
timesteps = 1000 * 0.25 * np.log(sigmas + 1e-44)
return timesteps
def set_timesteps(
self,
num_inference_steps: Optional[int] = None,
device: Union[str, torch.device] = None,
timesteps: Optional[List[int]] = None,
):
"""
Sets the timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
timesteps (`List[int]`, *optional*):
Custom timesteps used to support arbitrary spacing between timesteps. If `None`, then the default
timestep spacing strategy of equal spacing between timesteps is used. If `timesteps` is passed,
`num_inference_steps` must be `None`.
"""
if num_inference_steps is None and timesteps is None:
raise ValueError("Exactly one of `num_inference_steps` or `timesteps` must be supplied.")
if num_inference_steps is not None and timesteps is not None:
raise ValueError("Can only pass one of `num_inference_steps` or `timesteps`.")
# Follow DDPMScheduler custom timesteps logic
if timesteps is not None:
for i in range(1, len(timesteps)):
if timesteps[i] >= timesteps[i - 1]:
raise ValueError("`timesteps` must be in descending order.")
if timesteps[0] >= self.config.num_train_timesteps:
raise ValueError(
f"`timesteps` must start before `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps}."
)
timesteps = np.array(timesteps, dtype=np.int64)
self.custom_timesteps = True
else:
if num_inference_steps > self.config.num_train_timesteps:
raise ValueError(
f"`num_inference_steps`: {num_inference_steps} cannot be larger than `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps} as the unet model trained with this scheduler can only handle"
f" maximal {self.config.num_train_timesteps} timesteps."
)
self.num_inference_steps = num_inference_steps
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.int64)
self.custom_timesteps = False
# Map timesteps to Karras sigmas directly for multistep sampling
# See https://github.com/openai/consistency_models/blob/main/cm/karras_diffusion.py#L675
num_train_timesteps = self.config.num_train_timesteps
ramp = timesteps[::-1].copy()
ramp = ramp / (num_train_timesteps - 1)
sigmas = self._convert_to_karras(ramp)
timesteps = self.sigma_to_t(sigmas)
sigmas = np.concatenate([sigmas, [self.sigma_min]]).astype(np.float32)
self.sigmas = torch.from_numpy(sigmas).to(device=device)
if str(device).startswith("mps"):
# mps does not support float64
self.timesteps = torch.from_numpy(timesteps).to(device, dtype=torch.float32)
else:
self.timesteps = torch.from_numpy(timesteps).to(device=device)
self._step_index = None
# Modified _convert_to_karras implementation that takes in ramp as argument
def _convert_to_karras(self, ramp):
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = self.config.sigma_min
sigma_max: float = self.config.sigma_max
rho = self.config.rho
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
def get_scalings(self, sigma):
sigma_data = self.config.sigma_data
c_skip = sigma_data**2 / (sigma**2 + sigma_data**2)
c_out = sigma * sigma_data / (sigma**2 + sigma_data**2) ** 0.5
return c_skip, c_out
def get_scalings_for_boundary_condition(self, sigma):
"""
Gets the scalings used in the consistency model parameterization (from Appendix C of the
[paper](https://huggingface.co/papers/2303.01469)) to enforce boundary condition.
<Tip>
`epsilon` in the equations for `c_skip` and `c_out` is set to `sigma_min`.
</Tip>
Args:
sigma (`torch.FloatTensor`):
The current sigma in the Karras sigma schedule.
Returns:
`tuple`:
A two-element tuple where `c_skip` (which weights the current sample) is the first element and `c_out`
(which weights the consistency model output) is the second element.
"""
sigma_min = self.config.sigma_min
sigma_data = self.config.sigma_data
c_skip = sigma_data**2 / ((sigma - sigma_min) ** 2 + sigma_data**2)
c_out = (sigma - sigma_min) * sigma_data / (sigma**2 + sigma_data**2) ** 0.5
return c_skip, c_out
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
def step(
self,
model_output: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
sample: torch.FloatTensor,
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[CMStochasticIterativeSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`float`):
The current timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a
[`~schedulers.scheduling_consistency_models.CMStochasticIterativeSchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_consistency_models.CMStochasticIterativeSchedulerOutput`] or `tuple`:
If return_dict is `True`,
[`~schedulers.scheduling_consistency_models.CMStochasticIterativeSchedulerOutput`] is returned,
otherwise a tuple is returned where the first element is the sample tensor.
"""
if (
isinstance(timestep, int)
or isinstance(timestep, torch.IntTensor)
or isinstance(timestep, torch.LongTensor)
):
raise ValueError(
(
"Passing integer indices (e.g. from `enumerate(timesteps)`) as timesteps to"
f" `{self.__class__}.step()` is not supported. Make sure to pass"
" one of the `scheduler.timesteps` as a timestep."
),
)
if not self.is_scale_input_called:
logger.warning(
"The `scale_model_input` function should be called before `step` to ensure correct denoising. "
"See `StableDiffusionPipeline` for a usage example."
)
sigma_min = self.config.sigma_min
sigma_max = self.config.sigma_max
if self.step_index is None:
self._init_step_index(timestep)
# sigma_next corresponds to next_t in original implementation
sigma = self.sigmas[self.step_index]
if self.step_index + 1 < self.config.num_train_timesteps:
sigma_next = self.sigmas[self.step_index + 1]
else:
# Set sigma_next to sigma_min
sigma_next = self.sigmas[-1]
# Get scalings for boundary conditions
c_skip, c_out = self.get_scalings_for_boundary_condition(sigma)
# 1. Denoise model output using boundary conditions
denoised = c_out * model_output + c_skip * sample
if self.config.clip_denoised:
denoised = denoised.clamp(-1, 1)
# 2. Sample z ~ N(0, s_noise^2 * I)
# Noise is not used for onestep sampling.
if len(self.timesteps) > 1:
noise = randn_tensor(
model_output.shape, dtype=model_output.dtype, device=model_output.device, generator=generator
)
else:
noise = torch.zeros_like(model_output)
z = noise * self.config.s_noise
sigma_hat = sigma_next.clamp(min=sigma_min, max=sigma_max)
# 3. Return noisy sample
# tau = sigma_hat, eps = sigma_min
prev_sample = denoised + z * (sigma_hat**2 - sigma_min**2) ** 0.5
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return CMStochasticIterativeSchedulerOutput(prev_sample=prev_sample)
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [(schedule_timesteps == t).nonzero().item() for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_consistency_models.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import TYPE_CHECKING
from ..utils import (
OptionalDependencyNotAvailable,
_LazyModule,
get_objects_from_module,
is_flax_available,
is_scipy_available,
is_torch_available,
is_torchsde_available,
)
_dummy_modules = {}
_import_structure = {}
try:
if not is_torch_available():
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils import dummy_pt_objects # noqa F403
_dummy_modules.update(get_objects_from_module(dummy_pt_objects))
else:
_import_structure["scheduling_consistency_models"] = ["CMStochasticIterativeScheduler"]
_import_structure["scheduling_ddim"] = ["DDIMScheduler"]
_import_structure["scheduling_ddim_inverse"] = ["DDIMInverseScheduler"]
_import_structure["scheduling_ddim_parallel"] = ["DDIMParallelScheduler"]
_import_structure["scheduling_ddpm"] = ["DDPMScheduler"]
_import_structure["scheduling_ddpm_parallel"] = ["DDPMParallelScheduler"]
_import_structure["scheduling_ddpm_wuerstchen"] = ["DDPMWuerstchenScheduler"]
_import_structure["scheduling_deis_multistep"] = ["DEISMultistepScheduler"]
_import_structure["scheduling_dpmsolver_multistep"] = ["DPMSolverMultistepScheduler"]
_import_structure["scheduling_dpmsolver_multistep_inverse"] = ["DPMSolverMultistepInverseScheduler"]
_import_structure["scheduling_dpmsolver_singlestep"] = ["DPMSolverSinglestepScheduler"]
_import_structure["scheduling_euler_ancestral_discrete"] = ["EulerAncestralDiscreteScheduler"]
_import_structure["scheduling_euler_discrete"] = ["EulerDiscreteScheduler"]
_import_structure["scheduling_heun_discrete"] = ["HeunDiscreteScheduler"]
_import_structure["scheduling_ipndm"] = ["IPNDMScheduler"]
_import_structure["scheduling_k_dpm_2_ancestral_discrete"] = ["KDPM2AncestralDiscreteScheduler"]
_import_structure["scheduling_k_dpm_2_discrete"] = ["KDPM2DiscreteScheduler"]
_import_structure["scheduling_karras_ve"] = ["KarrasVeScheduler"]
_import_structure["scheduling_pndm"] = ["PNDMScheduler"]
_import_structure["scheduling_repaint"] = ["RePaintScheduler"]
_import_structure["scheduling_sde_ve"] = ["ScoreSdeVeScheduler"]
_import_structure["scheduling_sde_vp"] = ["ScoreSdeVpScheduler"]
_import_structure["scheduling_unclip"] = ["UnCLIPScheduler"]
_import_structure["scheduling_unipc_multistep"] = ["UniPCMultistepScheduler"]
_import_structure["scheduling_utils"] = ["KarrasDiffusionSchedulers", "SchedulerMixin"]
_import_structure["scheduling_vq_diffusion"] = ["VQDiffusionScheduler"]
try:
if not is_flax_available():
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils import dummy_flax_objects # noqa F403
_dummy_modules.update(get_objects_from_module(dummy_flax_objects))
else:
_import_structure["scheduling_ddim_flax"] = ["FlaxDDIMScheduler"]
_import_structure["scheduling_ddpm_flax"] = ["FlaxDDPMScheduler"]
_import_structure["scheduling_dpmsolver_multistep_flax"] = ["FlaxDPMSolverMultistepScheduler"]
_import_structure["scheduling_karras_ve_flax"] = ["FlaxKarrasVeScheduler"]
_import_structure["scheduling_lms_discrete_flax"] = ["FlaxLMSDiscreteScheduler"]
_import_structure["scheduling_pndm_flax"] = ["FlaxPNDMScheduler"]
_import_structure["scheduling_sde_ve_flax"] = ["FlaxScoreSdeVeScheduler"]
_import_structure["scheduling_utils_flax"] = [
"FlaxKarrasDiffusionSchedulers",
"FlaxSchedulerMixin",
"FlaxSchedulerOutput",
"broadcast_to_shape_from_left",
]
try:
if not (is_torch_available() and is_scipy_available()):
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils import dummy_torch_and_scipy_objects # noqa F403
_dummy_modules.update(get_objects_from_module(dummy_torch_and_scipy_objects))
else:
_import_structure["scheduling_lms_discrete"] = ["LMSDiscreteScheduler"]
try:
if not (is_torch_available() and is_torchsde_available()):
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils import dummy_torch_and_torchsde_objects # noqa F403
_dummy_modules.update(get_objects_from_module(dummy_torch_and_torchsde_objects))
else:
_import_structure["scheduling_dpmsolver_sde"] = ["DPMSolverSDEScheduler"]
if TYPE_CHECKING:
from ..utils import (
OptionalDependencyNotAvailable,
is_flax_available,
is_scipy_available,
is_torch_available,
is_torchsde_available,
)
try:
if not is_torch_available():
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils.dummy_pt_objects import * # noqa F403
else:
from .scheduling_consistency_models import CMStochasticIterativeScheduler
from .scheduling_ddim import DDIMScheduler
from .scheduling_ddim_inverse import DDIMInverseScheduler
from .scheduling_ddim_parallel import DDIMParallelScheduler
from .scheduling_ddpm import DDPMScheduler
from .scheduling_ddpm_parallel import DDPMParallelScheduler
from .scheduling_ddpm_wuerstchen import DDPMWuerstchenScheduler
from .scheduling_deis_multistep import DEISMultistepScheduler
from .scheduling_dpmsolver_multistep import DPMSolverMultistepScheduler
from .scheduling_dpmsolver_multistep_inverse import DPMSolverMultistepInverseScheduler
from .scheduling_dpmsolver_singlestep import DPMSolverSinglestepScheduler
from .scheduling_euler_ancestral_discrete import EulerAncestralDiscreteScheduler
from .scheduling_euler_discrete import EulerDiscreteScheduler
from .scheduling_heun_discrete import HeunDiscreteScheduler
from .scheduling_ipndm import IPNDMScheduler
from .scheduling_k_dpm_2_ancestral_discrete import KDPM2AncestralDiscreteScheduler
from .scheduling_k_dpm_2_discrete import KDPM2DiscreteScheduler
from .scheduling_karras_ve import KarrasVeScheduler
from .scheduling_pndm import PNDMScheduler
from .scheduling_repaint import RePaintScheduler
from .scheduling_sde_ve import ScoreSdeVeScheduler
from .scheduling_sde_vp import ScoreSdeVpScheduler
from .scheduling_unclip import UnCLIPScheduler
from .scheduling_unipc_multistep import UniPCMultistepScheduler
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
from .scheduling_vq_diffusion import VQDiffusionScheduler
try:
if not is_flax_available():
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils.dummy_flax_objects import * # noqa F403
else:
from .scheduling_ddim_flax import FlaxDDIMScheduler
from .scheduling_ddpm_flax import FlaxDDPMScheduler
from .scheduling_dpmsolver_multistep_flax import FlaxDPMSolverMultistepScheduler
from .scheduling_karras_ve_flax import FlaxKarrasVeScheduler
from .scheduling_lms_discrete_flax import FlaxLMSDiscreteScheduler
from .scheduling_pndm_flax import FlaxPNDMScheduler
from .scheduling_sde_ve_flax import FlaxScoreSdeVeScheduler
from .scheduling_utils_flax import (
FlaxKarrasDiffusionSchedulers,
FlaxSchedulerMixin,
FlaxSchedulerOutput,
broadcast_to_shape_from_left,
)
try:
if not (is_torch_available() and is_scipy_available()):
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils.dummy_torch_and_scipy_objects import * # noqa F403
else:
from .scheduling_lms_discrete import LMSDiscreteScheduler
try:
if not (is_torch_available() and is_torchsde_available()):
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ..utils.dummy_torch_and_torchsde_objects import * # noqa F403
else:
from .scheduling_dpmsolver_sde import DPMSolverSDEScheduler
else:
import sys
sys.modules[__name__] = _LazyModule(__name__, globals()["__file__"], _import_structure, module_spec=__spec__)
for name, value in _dummy_modules.items():
setattr(sys.modules[__name__], name, value)
| diffusers-main | src/diffusers/schedulers/__init__.py |
# Copyright 2023 TSAIL Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/LuChengTHU/dpm-solver
import math
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import logging
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DPMSolverSinglestepScheduler(SchedulerMixin, ConfigMixin):
"""
`DPMSolverSinglestepScheduler` is a fast dedicated high-order solver for diffusion ODEs.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
solver_order (`int`, defaults to 2):
The DPMSolver order which can be `1` or `2` or `3`. It is recommended to use `solver_order=2` for guided
sampling, and `solver_order=3` for unconditional sampling.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
thresholding (`bool`, defaults to `False`):
Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
as Stable Diffusion.
dynamic_thresholding_ratio (`float`, defaults to 0.995):
The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
sample_max_value (`float`, defaults to 1.0):
The threshold value for dynamic thresholding. Valid only when `thresholding=True` and
`algorithm_type="dpmsolver++"`.
algorithm_type (`str`, defaults to `dpmsolver++`):
Algorithm type for the solver; can be `dpmsolver`, `dpmsolver++`, `sde-dpmsolver` or `sde-dpmsolver++`. The
`dpmsolver` type implements the algorithms in the [DPMSolver](https://huggingface.co/papers/2206.00927)
paper, and the `dpmsolver++` type implements the algorithms in the
[DPMSolver++](https://huggingface.co/papers/2211.01095) paper. It is recommended to use `dpmsolver++` or
`sde-dpmsolver++` with `solver_order=2` for guided sampling like in Stable Diffusion.
solver_type (`str`, defaults to `midpoint`):
Solver type for the second-order solver; can be `midpoint` or `heun`. The solver type slightly affects the
sample quality, especially for a small number of steps. It is recommended to use `midpoint` solvers.
lower_order_final (`bool`, defaults to `True`):
Whether to use lower-order solvers in the final steps. Only valid for < 15 inference steps. This can
stabilize the sampling of DPMSolver for steps < 15, especially for steps <= 10.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
lambda_min_clipped (`float`, defaults to `-inf`):
Clipping threshold for the minimum value of `lambda(t)` for numerical stability. This is critical for the
cosine (`squaredcos_cap_v2`) noise schedule.
variance_type (`str`, *optional*):
Set to "learned" or "learned_range" for diffusion models that predict variance. If set, the model's output
contains the predicted Gaussian variance.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[np.ndarray] = None,
solver_order: int = 2,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
sample_max_value: float = 1.0,
algorithm_type: str = "dpmsolver++",
solver_type: str = "midpoint",
lower_order_final: bool = True,
use_karras_sigmas: Optional[bool] = False,
lambda_min_clipped: float = -float("inf"),
variance_type: Optional[str] = None,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# Currently we only support VP-type noise schedule
self.alpha_t = torch.sqrt(self.alphas_cumprod)
self.sigma_t = torch.sqrt(1 - self.alphas_cumprod)
self.lambda_t = torch.log(self.alpha_t) - torch.log(self.sigma_t)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# settings for DPM-Solver
if algorithm_type not in ["dpmsolver", "dpmsolver++"]:
if algorithm_type == "deis":
self.register_to_config(algorithm_type="dpmsolver++")
else:
raise NotImplementedError(f"{algorithm_type} does is not implemented for {self.__class__}")
if solver_type not in ["midpoint", "heun"]:
if solver_type in ["logrho", "bh1", "bh2"]:
self.register_to_config(solver_type="midpoint")
else:
raise NotImplementedError(f"{solver_type} does is not implemented for {self.__class__}")
# setable values
self.num_inference_steps = None
timesteps = np.linspace(0, num_train_timesteps - 1, num_train_timesteps, dtype=np.float32)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps)
self.model_outputs = [None] * solver_order
self.sample = None
self.order_list = self.get_order_list(num_train_timesteps)
def get_order_list(self, num_inference_steps: int) -> List[int]:
"""
Computes the solver order at each time step.
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
"""
steps = num_inference_steps
order = self.config.solver_order
if self.config.lower_order_final:
if order == 3:
if steps % 3 == 0:
orders = [1, 2, 3] * (steps // 3 - 1) + [1, 2] + [1]
elif steps % 3 == 1:
orders = [1, 2, 3] * (steps // 3) + [1]
else:
orders = [1, 2, 3] * (steps // 3) + [1, 2]
elif order == 2:
if steps % 2 == 0:
orders = [1, 2] * (steps // 2)
else:
orders = [1, 2] * (steps // 2) + [1]
elif order == 1:
orders = [1] * steps
else:
if order == 3:
orders = [1, 2, 3] * (steps // 3)
elif order == 2:
orders = [1, 2] * (steps // 2)
elif order == 1:
orders = [1] * steps
return orders
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
# Clipping the minimum of all lambda(t) for numerical stability.
# This is critical for cosine (squaredcos_cap_v2) noise schedule.
clipped_idx = torch.searchsorted(torch.flip(self.lambda_t, [0]), self.config.lambda_min_clipped)
timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1 - clipped_idx, num_inference_steps + 1)
.round()[::-1][:-1]
.copy()
.astype(np.int64)
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
if self.config.use_karras_sigmas:
log_sigmas = np.log(sigmas)
sigmas = self._convert_to_karras(in_sigmas=sigmas, num_inference_steps=num_inference_steps)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas]).round()
timesteps = np.flip(timesteps).copy().astype(np.int64)
self.sigmas = torch.from_numpy(sigmas)
self.timesteps = torch.from_numpy(timesteps).to(device)
self.model_outputs = [None] * self.config.solver_order
self.sample = None
if not self.config.lower_order_final and num_inference_steps % self.config.solver_order != 0:
logger.warn(
"Changing scheduler {self.config} to have `lower_order_final` set to True to handle uneven amount of inference steps. Please make sure to always use an even number of `num_inference steps when using `lower_order_final=True`."
)
self.register_to_config(lower_order_final=True)
self.order_list = self.get_order_list(num_inference_steps)
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._sigma_to_t
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._convert_to_karras
def _convert_to_karras(self, in_sigmas: torch.FloatTensor, num_inference_steps) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
def convert_model_output(
self, model_output: torch.FloatTensor, timestep: int, sample: torch.FloatTensor
) -> torch.FloatTensor:
"""
Convert the model output to the corresponding type the DPMSolver/DPMSolver++ algorithm needs. DPM-Solver is
designed to discretize an integral of the noise prediction model, and DPM-Solver++ is designed to discretize an
integral of the data prediction model.
<Tip>
The algorithm and model type are decoupled. You can use either DPMSolver or DPMSolver++ for both noise
prediction and data prediction models.
</Tip>
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The converted model output.
"""
# DPM-Solver++ needs to solve an integral of the data prediction model.
if self.config.algorithm_type == "dpmsolver++":
if self.config.prediction_type == "epsilon":
# DPM-Solver and DPM-Solver++ only need the "mean" output.
if self.config.variance_type in ["learned_range"]:
model_output = model_output[:, :3]
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = (sample - sigma_t * model_output) / alpha_t
elif self.config.prediction_type == "sample":
x0_pred = model_output
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = alpha_t * sample - sigma_t * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the DPMSolverSinglestepScheduler."
)
if self.config.thresholding:
x0_pred = self._threshold_sample(x0_pred)
return x0_pred
# DPM-Solver needs to solve an integral of the noise prediction model.
elif self.config.algorithm_type == "dpmsolver":
if self.config.prediction_type == "epsilon":
# DPM-Solver and DPM-Solver++ only need the "mean" output.
if self.config.variance_type in ["learned_range"]:
model_output = model_output[:, :3]
return model_output
elif self.config.prediction_type == "sample":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = (sample - alpha_t * model_output) / sigma_t
return epsilon
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = alpha_t * model_output + sigma_t * sample
return epsilon
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the DPMSolverSinglestepScheduler."
)
def dpm_solver_first_order_update(
self,
model_output: torch.FloatTensor,
timestep: int,
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the first-order DPMSolver (equivalent to DDIM).
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
lambda_t, lambda_s = self.lambda_t[prev_timestep], self.lambda_t[timestep]
alpha_t, alpha_s = self.alpha_t[prev_timestep], self.alpha_t[timestep]
sigma_t, sigma_s = self.sigma_t[prev_timestep], self.sigma_t[timestep]
h = lambda_t - lambda_s
if self.config.algorithm_type == "dpmsolver++":
x_t = (sigma_t / sigma_s) * sample - (alpha_t * (torch.exp(-h) - 1.0)) * model_output
elif self.config.algorithm_type == "dpmsolver":
x_t = (alpha_t / alpha_s) * sample - (sigma_t * (torch.exp(h) - 1.0)) * model_output
return x_t
def singlestep_dpm_solver_second_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the second-order singlestep DPMSolver that computes the solution at time `prev_timestep` from the
time `timestep_list[-2]`.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1 = prev_timestep, timestep_list[-1], timestep_list[-2]
m0, m1 = model_output_list[-1], model_output_list[-2]
lambda_t, lambda_s0, lambda_s1 = self.lambda_t[t], self.lambda_t[s0], self.lambda_t[s1]
alpha_t, alpha_s1 = self.alpha_t[t], self.alpha_t[s1]
sigma_t, sigma_s1 = self.sigma_t[t], self.sigma_t[s1]
h, h_0 = lambda_t - lambda_s1, lambda_s0 - lambda_s1
r0 = h_0 / h
D0, D1 = m1, (1.0 / r0) * (m0 - m1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2211.01095 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(sigma_t / sigma_s1) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
- 0.5 * (alpha_t * (torch.exp(-h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(sigma_t / sigma_s1) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
+ (alpha_t * ((torch.exp(-h) - 1.0) / h + 1.0)) * D1
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(alpha_t / alpha_s1) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- 0.5 * (sigma_t * (torch.exp(h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(alpha_t / alpha_s1) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1
)
return x_t
def singlestep_dpm_solver_third_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the third-order singlestep DPMSolver that computes the solution at time `prev_timestep` from the
time `timestep_list[-3]`.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1, s2 = prev_timestep, timestep_list[-1], timestep_list[-2], timestep_list[-3]
m0, m1, m2 = model_output_list[-1], model_output_list[-2], model_output_list[-3]
lambda_t, lambda_s0, lambda_s1, lambda_s2 = (
self.lambda_t[t],
self.lambda_t[s0],
self.lambda_t[s1],
self.lambda_t[s2],
)
alpha_t, alpha_s2 = self.alpha_t[t], self.alpha_t[s2]
sigma_t, sigma_s2 = self.sigma_t[t], self.sigma_t[s2]
h, h_0, h_1 = lambda_t - lambda_s2, lambda_s0 - lambda_s2, lambda_s1 - lambda_s2
r0, r1 = h_0 / h, h_1 / h
D0 = m2
D1_0, D1_1 = (1.0 / r1) * (m1 - m2), (1.0 / r0) * (m0 - m2)
D1 = (r0 * D1_0 - r1 * D1_1) / (r0 - r1)
D2 = 2.0 * (D1_1 - D1_0) / (r0 - r1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(sigma_t / sigma_s2) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
+ (alpha_t * ((torch.exp(-h) - 1.0) / h + 1.0)) * D1_1
)
elif self.config.solver_type == "heun":
x_t = (
(sigma_t / sigma_s2) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
+ (alpha_t * ((torch.exp(-h) - 1.0) / h + 1.0)) * D1
- (alpha_t * ((torch.exp(-h) - 1.0 + h) / h**2 - 0.5)) * D2
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(alpha_t / alpha_s2) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1_1
)
elif self.config.solver_type == "heun":
x_t = (
(alpha_t / alpha_s2) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1
- (sigma_t * ((torch.exp(h) - 1.0 - h) / h**2 - 0.5)) * D2
)
return x_t
def singlestep_dpm_solver_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
order: int,
) -> torch.FloatTensor:
"""
One step for the singlestep DPMSolver.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by diffusion process.
order (`int`):
The solver order at this step.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
if order == 1:
return self.dpm_solver_first_order_update(model_output_list[-1], timestep_list[-1], prev_timestep, sample)
elif order == 2:
return self.singlestep_dpm_solver_second_order_update(
model_output_list, timestep_list, prev_timestep, sample
)
elif order == 3:
return self.singlestep_dpm_solver_third_order_update(
model_output_list, timestep_list, prev_timestep, sample
)
else:
raise ValueError(f"Order must be 1, 2, 3, got {order}")
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the singlestep DPMSolver.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
step_index = (self.timesteps == timestep).nonzero()
if len(step_index) == 0:
step_index = len(self.timesteps) - 1
else:
step_index = step_index.item()
prev_timestep = 0 if step_index == len(self.timesteps) - 1 else self.timesteps[step_index + 1]
model_output = self.convert_model_output(model_output, timestep, sample)
for i in range(self.config.solver_order - 1):
self.model_outputs[i] = self.model_outputs[i + 1]
self.model_outputs[-1] = model_output
order = self.order_list[step_index]
# For img2img denoising might start with order>1 which is not possible
# In this case make sure that the first two steps are both order=1
while self.model_outputs[-order] is None:
order -= 1
# For single-step solvers, we use the initial value at each time with order = 1.
if order == 1:
self.sample = sample
timestep_list = [self.timesteps[step_index - i] for i in range(order - 1, 0, -1)] + [timestep]
prev_sample = self.singlestep_dpm_solver_update(
self.model_outputs, timestep_list, prev_timestep, self.sample, order
)
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def scale_model_input(self, sample: torch.FloatTensor, *args, **kwargs) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_dpmsolver_singlestep.py |
# Copyright 2023 Stanford University Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This code is strongly influenced by https://github.com/pesser/pytorch_diffusion
# and https://github.com/hojonathanho/diffusion
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import flax
import jax.numpy as jnp
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils_flax import (
CommonSchedulerState,
FlaxKarrasDiffusionSchedulers,
FlaxSchedulerMixin,
FlaxSchedulerOutput,
add_noise_common,
get_velocity_common,
)
@flax.struct.dataclass
class DDIMSchedulerState:
common: CommonSchedulerState
final_alpha_cumprod: jnp.ndarray
# setable values
init_noise_sigma: jnp.ndarray
timesteps: jnp.ndarray
num_inference_steps: Optional[int] = None
@classmethod
def create(
cls,
common: CommonSchedulerState,
final_alpha_cumprod: jnp.ndarray,
init_noise_sigma: jnp.ndarray,
timesteps: jnp.ndarray,
):
return cls(
common=common,
final_alpha_cumprod=final_alpha_cumprod,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
)
@dataclass
class FlaxDDIMSchedulerOutput(FlaxSchedulerOutput):
state: DDIMSchedulerState
class FlaxDDIMScheduler(FlaxSchedulerMixin, ConfigMixin):
"""
Denoising diffusion implicit models is a scheduler that extends the denoising procedure introduced in denoising
diffusion probabilistic models (DDPMs) with non-Markovian guidance.
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details, see the original paper: https://arxiv.org/abs/2010.02502
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
beta_start (`float`): the starting `beta` value of inference.
beta_end (`float`): the final `beta` value.
beta_schedule (`str`):
the beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`jnp.ndarray`, optional):
option to pass an array of betas directly to the constructor to bypass `beta_start`, `beta_end` etc.
clip_sample (`bool`, default `True`):
option to clip predicted sample between -1 and 1 for numerical stability.
set_alpha_to_one (`bool`, default `True`):
each diffusion step uses the value of alphas product at that step and at the previous one. For the final
step there is no previous alpha. When this option is `True` the previous alpha product is fixed to `1`,
otherwise it uses the value of alpha at step 0.
steps_offset (`int`, default `0`):
an offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False`, to make the last step use step 0 for the previous alpha product, as done in
stable diffusion.
prediction_type (`str`, default `epsilon`):
indicates whether the model predicts the noise (epsilon), or the samples. One of `epsilon`, `sample`.
`v-prediction` is not supported for this scheduler.
dtype (`jnp.dtype`, *optional*, defaults to `jnp.float32`):
the `dtype` used for params and computation.
"""
_compatibles = [e.name for e in FlaxKarrasDiffusionSchedulers]
dtype: jnp.dtype
@property
def has_state(self):
return True
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[jnp.ndarray] = None,
set_alpha_to_one: bool = True,
steps_offset: int = 0,
prediction_type: str = "epsilon",
dtype: jnp.dtype = jnp.float32,
):
self.dtype = dtype
def create_state(self, common: Optional[CommonSchedulerState] = None) -> DDIMSchedulerState:
if common is None:
common = CommonSchedulerState.create(self)
# At every step in ddim, we are looking into the previous alphas_cumprod
# For the final step, there is no previous alphas_cumprod because we are already at 0
# `set_alpha_to_one` decides whether we set this parameter simply to one or
# whether we use the final alpha of the "non-previous" one.
final_alpha_cumprod = (
jnp.array(1.0, dtype=self.dtype) if self.config.set_alpha_to_one else common.alphas_cumprod[0]
)
# standard deviation of the initial noise distribution
init_noise_sigma = jnp.array(1.0, dtype=self.dtype)
timesteps = jnp.arange(0, self.config.num_train_timesteps).round()[::-1]
return DDIMSchedulerState.create(
common=common,
final_alpha_cumprod=final_alpha_cumprod,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
)
def scale_model_input(
self, state: DDIMSchedulerState, sample: jnp.ndarray, timestep: Optional[int] = None
) -> jnp.ndarray:
"""
Args:
state (`PNDMSchedulerState`): the `FlaxPNDMScheduler` state data class instance.
sample (`jnp.ndarray`): input sample
timestep (`int`, optional): current timestep
Returns:
`jnp.ndarray`: scaled input sample
"""
return sample
def set_timesteps(
self, state: DDIMSchedulerState, num_inference_steps: int, shape: Tuple = ()
) -> DDIMSchedulerState:
"""
Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
state (`DDIMSchedulerState`):
the `FlaxDDIMScheduler` state data class instance.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
"""
step_ratio = self.config.num_train_timesteps // num_inference_steps
# creates integer timesteps by multiplying by ratio
# rounding to avoid issues when num_inference_step is power of 3
timesteps = (jnp.arange(0, num_inference_steps) * step_ratio).round()[::-1] + self.config.steps_offset
return state.replace(
num_inference_steps=num_inference_steps,
timesteps=timesteps,
)
def _get_variance(self, state: DDIMSchedulerState, timestep, prev_timestep):
alpha_prod_t = state.common.alphas_cumprod[timestep]
alpha_prod_t_prev = jnp.where(
prev_timestep >= 0, state.common.alphas_cumprod[prev_timestep], state.final_alpha_cumprod
)
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
variance = (beta_prod_t_prev / beta_prod_t) * (1 - alpha_prod_t / alpha_prod_t_prev)
return variance
def step(
self,
state: DDIMSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
eta: float = 0.0,
return_dict: bool = True,
) -> Union[FlaxDDIMSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
state (`DDIMSchedulerState`): the `FlaxDDIMScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
return_dict (`bool`): option for returning tuple rather than FlaxDDIMSchedulerOutput class
Returns:
[`FlaxDDIMSchedulerOutput`] or `tuple`: [`FlaxDDIMSchedulerOutput`] if `return_dict` is True, otherwise a
`tuple`. When returning a tuple, the first element is the sample tensor.
"""
if state.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
# See formulas (12) and (16) of DDIM paper https://arxiv.org/pdf/2010.02502.pdf
# Ideally, read DDIM paper in-detail understanding
# Notation (<variable name> -> <name in paper>
# - pred_noise_t -> e_theta(x_t, t)
# - pred_original_sample -> f_theta(x_t, t) or x_0
# - std_dev_t -> sigma_t
# - eta -> η
# - pred_sample_direction -> "direction pointing to x_t"
# - pred_prev_sample -> "x_t-1"
# 1. get previous step value (=t-1)
prev_timestep = timestep - self.config.num_train_timesteps // state.num_inference_steps
alphas_cumprod = state.common.alphas_cumprod
final_alpha_cumprod = state.final_alpha_cumprod
# 2. compute alphas, betas
alpha_prod_t = alphas_cumprod[timestep]
alpha_prod_t_prev = jnp.where(prev_timestep >= 0, alphas_cumprod[prev_timestep], final_alpha_cumprod)
beta_prod_t = 1 - alpha_prod_t
# 3. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
pred_epsilon = model_output
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
pred_epsilon = (alpha_prod_t**0.5) * model_output + (beta_prod_t**0.5) * sample
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction`"
)
# 4. compute variance: "sigma_t(η)" -> see formula (16)
# σ_t = sqrt((1 − α_t−1)/(1 − α_t)) * sqrt(1 − α_t/α_t−1)
variance = self._get_variance(state, timestep, prev_timestep)
std_dev_t = eta * variance ** (0.5)
# 5. compute "direction pointing to x_t" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
pred_sample_direction = (1 - alpha_prod_t_prev - std_dev_t**2) ** (0.5) * pred_epsilon
# 6. compute x_t without "random noise" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
prev_sample = alpha_prod_t_prev ** (0.5) * pred_original_sample + pred_sample_direction
if not return_dict:
return (prev_sample, state)
return FlaxDDIMSchedulerOutput(prev_sample=prev_sample, state=state)
def add_noise(
self,
state: DDIMSchedulerState,
original_samples: jnp.ndarray,
noise: jnp.ndarray,
timesteps: jnp.ndarray,
) -> jnp.ndarray:
return add_noise_common(state.common, original_samples, noise, timesteps)
def get_velocity(
self,
state: DDIMSchedulerState,
sample: jnp.ndarray,
noise: jnp.ndarray,
timesteps: jnp.ndarray,
) -> jnp.ndarray:
return get_velocity_common(state.common, sample, noise, timesteps)
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_ddim_flax.py |
# Copyright 2023 TSAIL Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/LuChengTHU/dpm-solver
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import flax
import jax
import jax.numpy as jnp
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils_flax import (
CommonSchedulerState,
FlaxKarrasDiffusionSchedulers,
FlaxSchedulerMixin,
FlaxSchedulerOutput,
add_noise_common,
)
@flax.struct.dataclass
class DPMSolverMultistepSchedulerState:
common: CommonSchedulerState
alpha_t: jnp.ndarray
sigma_t: jnp.ndarray
lambda_t: jnp.ndarray
# setable values
init_noise_sigma: jnp.ndarray
timesteps: jnp.ndarray
num_inference_steps: Optional[int] = None
# running values
model_outputs: Optional[jnp.ndarray] = None
lower_order_nums: Optional[jnp.int32] = None
prev_timestep: Optional[jnp.int32] = None
cur_sample: Optional[jnp.ndarray] = None
@classmethod
def create(
cls,
common: CommonSchedulerState,
alpha_t: jnp.ndarray,
sigma_t: jnp.ndarray,
lambda_t: jnp.ndarray,
init_noise_sigma: jnp.ndarray,
timesteps: jnp.ndarray,
):
return cls(
common=common,
alpha_t=alpha_t,
sigma_t=sigma_t,
lambda_t=lambda_t,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
)
@dataclass
class FlaxDPMSolverMultistepSchedulerOutput(FlaxSchedulerOutput):
state: DPMSolverMultistepSchedulerState
class FlaxDPMSolverMultistepScheduler(FlaxSchedulerMixin, ConfigMixin):
"""
DPM-Solver (and the improved version DPM-Solver++) is a fast dedicated high-order solver for diffusion ODEs with
the convergence order guarantee. Empirically, sampling by DPM-Solver with only 20 steps can generate high-quality
samples, and it can generate quite good samples even in only 10 steps.
For more details, see the original paper: https://arxiv.org/abs/2206.00927 and https://arxiv.org/abs/2211.01095
Currently, we support the multistep DPM-Solver for both noise prediction models and data prediction models. We
recommend to use `solver_order=2` for guided sampling, and `solver_order=3` for unconditional sampling.
We also support the "dynamic thresholding" method in Imagen (https://arxiv.org/abs/2205.11487). For pixel-space
diffusion models, you can set both `algorithm_type="dpmsolver++"` and `thresholding=True` to use the dynamic
thresholding. Note that the thresholding method is unsuitable for latent-space diffusion models (such as
stable-diffusion).
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details, see the original paper: https://arxiv.org/abs/2206.00927 and https://arxiv.org/abs/2211.01095
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
beta_start (`float`): the starting `beta` value of inference.
beta_end (`float`): the final `beta` value.
beta_schedule (`str`):
the beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, optional):
option to pass an array of betas directly to the constructor to bypass `beta_start`, `beta_end` etc.
solver_order (`int`, default `2`):
the order of DPM-Solver; can be `1` or `2` or `3`. We recommend to use `solver_order=2` for guided
sampling, and `solver_order=3` for unconditional sampling.
prediction_type (`str`, default `epsilon`):
indicates whether the model predicts the noise (epsilon), or the data / `x0`. One of `epsilon`, `sample`,
or `v-prediction`.
thresholding (`bool`, default `False`):
whether to use the "dynamic thresholding" method (introduced by Imagen, https://arxiv.org/abs/2205.11487).
For pixel-space diffusion models, you can set both `algorithm_type=dpmsolver++` and `thresholding=True` to
use the dynamic thresholding. Note that the thresholding method is unsuitable for latent-space diffusion
models (such as stable-diffusion).
dynamic_thresholding_ratio (`float`, default `0.995`):
the ratio for the dynamic thresholding method. Default is `0.995`, the same as Imagen
(https://arxiv.org/abs/2205.11487).
sample_max_value (`float`, default `1.0`):
the threshold value for dynamic thresholding. Valid only when `thresholding=True` and
`algorithm_type="dpmsolver++`.
algorithm_type (`str`, default `dpmsolver++`):
the algorithm type for the solver. Either `dpmsolver` or `dpmsolver++`. The `dpmsolver` type implements the
algorithms in https://arxiv.org/abs/2206.00927, and the `dpmsolver++` type implements the algorithms in
https://arxiv.org/abs/2211.01095. We recommend to use `dpmsolver++` with `solver_order=2` for guided
sampling (e.g. stable-diffusion).
solver_type (`str`, default `midpoint`):
the solver type for the second-order solver. Either `midpoint` or `heun`. The solver type slightly affects
the sample quality, especially for small number of steps. We empirically find that `midpoint` solvers are
slightly better, so we recommend to use the `midpoint` type.
lower_order_final (`bool`, default `True`):
whether to use lower-order solvers in the final steps. Only valid for < 15 inference steps. We empirically
find this trick can stabilize the sampling of DPM-Solver for steps < 15, especially for steps <= 10.
dtype (`jnp.dtype`, *optional*, defaults to `jnp.float32`):
the `dtype` used for params and computation.
"""
_compatibles = [e.name for e in FlaxKarrasDiffusionSchedulers]
dtype: jnp.dtype
@property
def has_state(self):
return True
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[jnp.ndarray] = None,
solver_order: int = 2,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
sample_max_value: float = 1.0,
algorithm_type: str = "dpmsolver++",
solver_type: str = "midpoint",
lower_order_final: bool = True,
dtype: jnp.dtype = jnp.float32,
):
self.dtype = dtype
def create_state(self, common: Optional[CommonSchedulerState] = None) -> DPMSolverMultistepSchedulerState:
if common is None:
common = CommonSchedulerState.create(self)
# Currently we only support VP-type noise schedule
alpha_t = jnp.sqrt(common.alphas_cumprod)
sigma_t = jnp.sqrt(1 - common.alphas_cumprod)
lambda_t = jnp.log(alpha_t) - jnp.log(sigma_t)
# settings for DPM-Solver
if self.config.algorithm_type not in ["dpmsolver", "dpmsolver++"]:
raise NotImplementedError(f"{self.config.algorithm_type} does is not implemented for {self.__class__}")
if self.config.solver_type not in ["midpoint", "heun"]:
raise NotImplementedError(f"{self.config.solver_type} does is not implemented for {self.__class__}")
# standard deviation of the initial noise distribution
init_noise_sigma = jnp.array(1.0, dtype=self.dtype)
timesteps = jnp.arange(0, self.config.num_train_timesteps).round()[::-1]
return DPMSolverMultistepSchedulerState.create(
common=common,
alpha_t=alpha_t,
sigma_t=sigma_t,
lambda_t=lambda_t,
init_noise_sigma=init_noise_sigma,
timesteps=timesteps,
)
def set_timesteps(
self, state: DPMSolverMultistepSchedulerState, num_inference_steps: int, shape: Tuple
) -> DPMSolverMultistepSchedulerState:
"""
Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
state (`DPMSolverMultistepSchedulerState`):
the `FlaxDPMSolverMultistepScheduler` state data class instance.
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
shape (`Tuple`):
the shape of the samples to be generated.
"""
timesteps = (
jnp.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps + 1)
.round()[::-1][:-1]
.astype(jnp.int32)
)
# initial running values
model_outputs = jnp.zeros((self.config.solver_order,) + shape, dtype=self.dtype)
lower_order_nums = jnp.int32(0)
prev_timestep = jnp.int32(-1)
cur_sample = jnp.zeros(shape, dtype=self.dtype)
return state.replace(
num_inference_steps=num_inference_steps,
timesteps=timesteps,
model_outputs=model_outputs,
lower_order_nums=lower_order_nums,
prev_timestep=prev_timestep,
cur_sample=cur_sample,
)
def convert_model_output(
self,
state: DPMSolverMultistepSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
) -> jnp.ndarray:
"""
Convert the model output to the corresponding type that the algorithm (DPM-Solver / DPM-Solver++) needs.
DPM-Solver is designed to discretize an integral of the noise prediction model, and DPM-Solver++ is designed to
discretize an integral of the data prediction model. So we need to first convert the model output to the
corresponding type to match the algorithm.
Note that the algorithm type and the model type is decoupled. That is to say, we can use either DPM-Solver or
DPM-Solver++ for both noise prediction model and data prediction model.
Args:
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
Returns:
`jnp.ndarray`: the converted model output.
"""
# DPM-Solver++ needs to solve an integral of the data prediction model.
if self.config.algorithm_type == "dpmsolver++":
if self.config.prediction_type == "epsilon":
alpha_t, sigma_t = state.alpha_t[timestep], state.sigma_t[timestep]
x0_pred = (sample - sigma_t * model_output) / alpha_t
elif self.config.prediction_type == "sample":
x0_pred = model_output
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = state.alpha_t[timestep], state.sigma_t[timestep]
x0_pred = alpha_t * sample - sigma_t * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, "
" or `v_prediction` for the FlaxDPMSolverMultistepScheduler."
)
if self.config.thresholding:
# Dynamic thresholding in https://arxiv.org/abs/2205.11487
dynamic_max_val = jnp.percentile(
jnp.abs(x0_pred), self.config.dynamic_thresholding_ratio, axis=tuple(range(1, x0_pred.ndim))
)
dynamic_max_val = jnp.maximum(
dynamic_max_val, self.config.sample_max_value * jnp.ones_like(dynamic_max_val)
)
x0_pred = jnp.clip(x0_pred, -dynamic_max_val, dynamic_max_val) / dynamic_max_val
return x0_pred
# DPM-Solver needs to solve an integral of the noise prediction model.
elif self.config.algorithm_type == "dpmsolver":
if self.config.prediction_type == "epsilon":
return model_output
elif self.config.prediction_type == "sample":
alpha_t, sigma_t = state.alpha_t[timestep], state.sigma_t[timestep]
epsilon = (sample - alpha_t * model_output) / sigma_t
return epsilon
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = state.alpha_t[timestep], state.sigma_t[timestep]
epsilon = alpha_t * model_output + sigma_t * sample
return epsilon
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, "
" or `v_prediction` for the FlaxDPMSolverMultistepScheduler."
)
def dpm_solver_first_order_update(
self,
state: DPMSolverMultistepSchedulerState,
model_output: jnp.ndarray,
timestep: int,
prev_timestep: int,
sample: jnp.ndarray,
) -> jnp.ndarray:
"""
One step for the first-order DPM-Solver (equivalent to DDIM).
See https://arxiv.org/abs/2206.00927 for the detailed derivation.
Args:
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
prev_timestep (`int`): previous discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
Returns:
`jnp.ndarray`: the sample tensor at the previous timestep.
"""
t, s0 = prev_timestep, timestep
m0 = model_output
lambda_t, lambda_s = state.lambda_t[t], state.lambda_t[s0]
alpha_t, alpha_s = state.alpha_t[t], state.alpha_t[s0]
sigma_t, sigma_s = state.sigma_t[t], state.sigma_t[s0]
h = lambda_t - lambda_s
if self.config.algorithm_type == "dpmsolver++":
x_t = (sigma_t / sigma_s) * sample - (alpha_t * (jnp.exp(-h) - 1.0)) * m0
elif self.config.algorithm_type == "dpmsolver":
x_t = (alpha_t / alpha_s) * sample - (sigma_t * (jnp.exp(h) - 1.0)) * m0
return x_t
def multistep_dpm_solver_second_order_update(
self,
state: DPMSolverMultistepSchedulerState,
model_output_list: jnp.ndarray,
timestep_list: List[int],
prev_timestep: int,
sample: jnp.ndarray,
) -> jnp.ndarray:
"""
One step for the second-order multistep DPM-Solver.
Args:
model_output_list (`List[jnp.ndarray]`):
direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`): current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`): previous discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
Returns:
`jnp.ndarray`: the sample tensor at the previous timestep.
"""
t, s0, s1 = prev_timestep, timestep_list[-1], timestep_list[-2]
m0, m1 = model_output_list[-1], model_output_list[-2]
lambda_t, lambda_s0, lambda_s1 = state.lambda_t[t], state.lambda_t[s0], state.lambda_t[s1]
alpha_t, alpha_s0 = state.alpha_t[t], state.alpha_t[s0]
sigma_t, sigma_s0 = state.sigma_t[t], state.sigma_t[s0]
h, h_0 = lambda_t - lambda_s0, lambda_s0 - lambda_s1
r0 = h_0 / h
D0, D1 = m0, (1.0 / r0) * (m0 - m1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2211.01095 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (jnp.exp(-h) - 1.0)) * D0
- 0.5 * (alpha_t * (jnp.exp(-h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (jnp.exp(-h) - 1.0)) * D0
+ (alpha_t * ((jnp.exp(-h) - 1.0) / h + 1.0)) * D1
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (jnp.exp(h) - 1.0)) * D0
- 0.5 * (sigma_t * (jnp.exp(h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (jnp.exp(h) - 1.0)) * D0
- (sigma_t * ((jnp.exp(h) - 1.0) / h - 1.0)) * D1
)
return x_t
def multistep_dpm_solver_third_order_update(
self,
state: DPMSolverMultistepSchedulerState,
model_output_list: jnp.ndarray,
timestep_list: List[int],
prev_timestep: int,
sample: jnp.ndarray,
) -> jnp.ndarray:
"""
One step for the third-order multistep DPM-Solver.
Args:
model_output_list (`List[jnp.ndarray]`):
direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`): current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`): previous discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
Returns:
`jnp.ndarray`: the sample tensor at the previous timestep.
"""
t, s0, s1, s2 = prev_timestep, timestep_list[-1], timestep_list[-2], timestep_list[-3]
m0, m1, m2 = model_output_list[-1], model_output_list[-2], model_output_list[-3]
lambda_t, lambda_s0, lambda_s1, lambda_s2 = (
state.lambda_t[t],
state.lambda_t[s0],
state.lambda_t[s1],
state.lambda_t[s2],
)
alpha_t, alpha_s0 = state.alpha_t[t], state.alpha_t[s0]
sigma_t, sigma_s0 = state.sigma_t[t], state.sigma_t[s0]
h, h_0, h_1 = lambda_t - lambda_s0, lambda_s0 - lambda_s1, lambda_s1 - lambda_s2
r0, r1 = h_0 / h, h_1 / h
D0 = m0
D1_0, D1_1 = (1.0 / r0) * (m0 - m1), (1.0 / r1) * (m1 - m2)
D1 = D1_0 + (r0 / (r0 + r1)) * (D1_0 - D1_1)
D2 = (1.0 / (r0 + r1)) * (D1_0 - D1_1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (jnp.exp(-h) - 1.0)) * D0
+ (alpha_t * ((jnp.exp(-h) - 1.0) / h + 1.0)) * D1
- (alpha_t * ((jnp.exp(-h) - 1.0 + h) / h**2 - 0.5)) * D2
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (jnp.exp(h) - 1.0)) * D0
- (sigma_t * ((jnp.exp(h) - 1.0) / h - 1.0)) * D1
- (sigma_t * ((jnp.exp(h) - 1.0 - h) / h**2 - 0.5)) * D2
)
return x_t
def step(
self,
state: DPMSolverMultistepSchedulerState,
model_output: jnp.ndarray,
timestep: int,
sample: jnp.ndarray,
return_dict: bool = True,
) -> Union[FlaxDPMSolverMultistepSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by DPM-Solver. Core function to propagate the diffusion process
from the learned model outputs (most often the predicted noise).
Args:
state (`DPMSolverMultistepSchedulerState`):
the `FlaxDPMSolverMultistepScheduler` state data class instance.
model_output (`jnp.ndarray`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`jnp.ndarray`):
current instance of sample being created by diffusion process.
return_dict (`bool`): option for returning tuple rather than FlaxDPMSolverMultistepSchedulerOutput class
Returns:
[`FlaxDPMSolverMultistepSchedulerOutput`] or `tuple`: [`FlaxDPMSolverMultistepSchedulerOutput`] if
`return_dict` is True, otherwise a `tuple`. When returning a tuple, the first element is the sample tensor.
"""
if state.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
(step_index,) = jnp.where(state.timesteps == timestep, size=1)
step_index = step_index[0]
prev_timestep = jax.lax.select(step_index == len(state.timesteps) - 1, 0, state.timesteps[step_index + 1])
model_output = self.convert_model_output(state, model_output, timestep, sample)
model_outputs_new = jnp.roll(state.model_outputs, -1, axis=0)
model_outputs_new = model_outputs_new.at[-1].set(model_output)
state = state.replace(
model_outputs=model_outputs_new,
prev_timestep=prev_timestep,
cur_sample=sample,
)
def step_1(state: DPMSolverMultistepSchedulerState) -> jnp.ndarray:
return self.dpm_solver_first_order_update(
state,
state.model_outputs[-1],
state.timesteps[step_index],
state.prev_timestep,
state.cur_sample,
)
def step_23(state: DPMSolverMultistepSchedulerState) -> jnp.ndarray:
def step_2(state: DPMSolverMultistepSchedulerState) -> jnp.ndarray:
timestep_list = jnp.array([state.timesteps[step_index - 1], state.timesteps[step_index]])
return self.multistep_dpm_solver_second_order_update(
state,
state.model_outputs,
timestep_list,
state.prev_timestep,
state.cur_sample,
)
def step_3(state: DPMSolverMultistepSchedulerState) -> jnp.ndarray:
timestep_list = jnp.array(
[
state.timesteps[step_index - 2],
state.timesteps[step_index - 1],
state.timesteps[step_index],
]
)
return self.multistep_dpm_solver_third_order_update(
state,
state.model_outputs,
timestep_list,
state.prev_timestep,
state.cur_sample,
)
step_2_output = step_2(state)
step_3_output = step_3(state)
if self.config.solver_order == 2:
return step_2_output
elif self.config.lower_order_final and len(state.timesteps) < 15:
return jax.lax.select(
state.lower_order_nums < 2,
step_2_output,
jax.lax.select(
step_index == len(state.timesteps) - 2,
step_2_output,
step_3_output,
),
)
else:
return jax.lax.select(
state.lower_order_nums < 2,
step_2_output,
step_3_output,
)
step_1_output = step_1(state)
step_23_output = step_23(state)
if self.config.solver_order == 1:
prev_sample = step_1_output
elif self.config.lower_order_final and len(state.timesteps) < 15:
prev_sample = jax.lax.select(
state.lower_order_nums < 1,
step_1_output,
jax.lax.select(
step_index == len(state.timesteps) - 1,
step_1_output,
step_23_output,
),
)
else:
prev_sample = jax.lax.select(
state.lower_order_nums < 1,
step_1_output,
step_23_output,
)
state = state.replace(
lower_order_nums=jnp.minimum(state.lower_order_nums + 1, self.config.solver_order),
)
if not return_dict:
return (prev_sample, state)
return FlaxDPMSolverMultistepSchedulerOutput(prev_sample=prev_sample, state=state)
def scale_model_input(
self, state: DPMSolverMultistepSchedulerState, sample: jnp.ndarray, timestep: Optional[int] = None
) -> jnp.ndarray:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
state (`DPMSolverMultistepSchedulerState`):
the `FlaxDPMSolverMultistepScheduler` state data class instance.
sample (`jnp.ndarray`): input sample
timestep (`int`, optional): current timestep
Returns:
`jnp.ndarray`: scaled input sample
"""
return sample
def add_noise(
self,
state: DPMSolverMultistepSchedulerState,
original_samples: jnp.ndarray,
noise: jnp.ndarray,
timesteps: jnp.ndarray,
) -> jnp.ndarray:
return add_noise_common(state.common, original_samples, noise, timesteps)
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_dpmsolver_multistep_flax.py |
# Copyright 2023 Katherine Crowson and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput, logging
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput with DDPM->EulerAncestralDiscrete
class EulerAncestralDiscreteSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class EulerAncestralDiscreteScheduler(SchedulerMixin, ConfigMixin):
"""
Ancestral sampling with Euler method steps.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear` or `scaled_linear`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
prediction_type: str = "epsilon",
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
sigmas = np.concatenate([sigmas[::-1], [0.0]]).astype(np.float32)
self.sigmas = torch.from_numpy(sigmas)
# setable values
self.num_inference_steps = None
timesteps = np.linspace(0, num_train_timesteps - 1, num_train_timesteps, dtype=float)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps)
self.is_scale_input_called = False
self._step_index = None
@property
def init_noise_sigma(self):
# standard deviation of the initial noise distribution
if self.config.timestep_spacing in ["linspace", "trailing"]:
return self.sigmas.max()
return (self.sigmas.max() ** 2 + 1) ** 0.5
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def scale_model_input(
self, sample: torch.FloatTensor, timestep: Union[float, torch.FloatTensor]
) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep. Scales the denoising model input by `(sigma**2 + 1) ** 0.5` to match the Euler algorithm.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
sample = sample / ((sigma**2 + 1) ** 0.5)
self.is_scale_input_called = True
return sample
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps, dtype=np.float32)[
::-1
].copy()
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.float32)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(self.config.num_train_timesteps, 0, -step_ratio)).round().copy().astype(np.float32)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
sigmas = np.interp(timesteps, np.arange(0, len(sigmas)), sigmas)
sigmas = np.concatenate([sigmas, [0.0]]).astype(np.float32)
self.sigmas = torch.from_numpy(sigmas).to(device=device)
self.timesteps = torch.from_numpy(timesteps).to(device=device)
self._step_index = None
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
def step(
self,
model_output: torch.FloatTensor,
timestep: Union[float, torch.FloatTensor],
sample: torch.FloatTensor,
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[EulerAncestralDiscreteSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`):
Whether or not to return a
[`~schedulers.scheduling_euler_ancestral_discrete.EulerAncestralDiscreteSchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_euler_ancestral_discrete.EulerAncestralDiscreteSchedulerOutput`] or `tuple`:
If return_dict is `True`,
[`~schedulers.scheduling_euler_ancestral_discrete.EulerAncestralDiscreteSchedulerOutput`] is returned,
otherwise a tuple is returned where the first element is the sample tensor.
"""
if (
isinstance(timestep, int)
or isinstance(timestep, torch.IntTensor)
or isinstance(timestep, torch.LongTensor)
):
raise ValueError(
(
"Passing integer indices (e.g. from `enumerate(timesteps)`) as timesteps to"
" `EulerDiscreteScheduler.step()` is not supported. Make sure to pass"
" one of the `scheduler.timesteps` as a timestep."
),
)
if not self.is_scale_input_called:
logger.warning(
"The `scale_model_input` function should be called before `step` to ensure correct denoising. "
"See `StableDiffusionPipeline` for a usage example."
)
if self.step_index is None:
self._init_step_index(timestep)
sigma = self.sigmas[self.step_index]
# 1. compute predicted original sample (x_0) from sigma-scaled predicted noise
if self.config.prediction_type == "epsilon":
pred_original_sample = sample - sigma * model_output
elif self.config.prediction_type == "v_prediction":
# * c_out + input * c_skip
pred_original_sample = model_output * (-sigma / (sigma**2 + 1) ** 0.5) + (sample / (sigma**2 + 1))
elif self.config.prediction_type == "sample":
raise NotImplementedError("prediction_type not implemented yet: sample")
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, or `v_prediction`"
)
sigma_from = self.sigmas[self.step_index]
sigma_to = self.sigmas[self.step_index + 1]
sigma_up = (sigma_to**2 * (sigma_from**2 - sigma_to**2) / sigma_from**2) ** 0.5
sigma_down = (sigma_to**2 - sigma_up**2) ** 0.5
# 2. Convert to an ODE derivative
derivative = (sample - pred_original_sample) / sigma
dt = sigma_down - sigma
prev_sample = sample + derivative * dt
device = model_output.device
noise = randn_tensor(model_output.shape, dtype=model_output.dtype, device=device, generator=generator)
prev_sample = prev_sample + noise * sigma_up
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return EulerAncestralDiscreteSchedulerOutput(
prev_sample=prev_sample, pred_original_sample=pred_original_sample
)
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
sigmas = self.sigmas.to(device=original_samples.device, dtype=original_samples.dtype)
if original_samples.device.type == "mps" and torch.is_floating_point(timesteps):
# mps does not support float64
schedule_timesteps = self.timesteps.to(original_samples.device, dtype=torch.float32)
timesteps = timesteps.to(original_samples.device, dtype=torch.float32)
else:
schedule_timesteps = self.timesteps.to(original_samples.device)
timesteps = timesteps.to(original_samples.device)
step_indices = [(schedule_timesteps == t).nonzero().item() for t in timesteps]
sigma = sigmas[step_indices].flatten()
while len(sigma.shape) < len(original_samples.shape):
sigma = sigma.unsqueeze(-1)
noisy_samples = original_samples + noise * sigma
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_euler_ancestral_discrete.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import importlib
import os
from dataclasses import dataclass
from enum import Enum
from typing import Any, Dict, Optional, Union
import torch
from ..utils import BaseOutput, PushToHubMixin
SCHEDULER_CONFIG_NAME = "scheduler_config.json"
# NOTE: We make this type an enum because it simplifies usage in docs and prevents
# circular imports when used for `_compatibles` within the schedulers module.
# When it's used as a type in pipelines, it really is a Union because the actual
# scheduler instance is passed in.
class KarrasDiffusionSchedulers(Enum):
DDIMScheduler = 1
DDPMScheduler = 2
PNDMScheduler = 3
LMSDiscreteScheduler = 4
EulerDiscreteScheduler = 5
HeunDiscreteScheduler = 6
EulerAncestralDiscreteScheduler = 7
DPMSolverMultistepScheduler = 8
DPMSolverSinglestepScheduler = 9
KDPM2DiscreteScheduler = 10
KDPM2AncestralDiscreteScheduler = 11
DEISMultistepScheduler = 12
UniPCMultistepScheduler = 13
DPMSolverSDEScheduler = 14
@dataclass
class SchedulerOutput(BaseOutput):
"""
Base class for the output of a scheduler's `step` function.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
"""
prev_sample: torch.FloatTensor
class SchedulerMixin(PushToHubMixin):
"""
Base class for all schedulers.
[`SchedulerMixin`] contains common functions shared by all schedulers such as general loading and saving
functionalities.
[`ConfigMixin`] takes care of storing the configuration attributes (like `num_train_timesteps`) that are passed to
the scheduler's `__init__` function, and the attributes can be accessed by `scheduler.config.num_train_timesteps`.
Class attributes:
- **_compatibles** (`List[str]`) -- A list of scheduler classes that are compatible with the parent scheduler
class. Use [`~ConfigMixin.from_config`] to load a different compatible scheduler class (should be overridden
by parent class).
"""
config_name = SCHEDULER_CONFIG_NAME
_compatibles = []
has_compatibles = True
@classmethod
def from_pretrained(
cls,
pretrained_model_name_or_path: Dict[str, Any] = None,
subfolder: Optional[str] = None,
return_unused_kwargs=False,
**kwargs,
):
r"""
Instantiate a scheduler from a pre-defined JSON configuration file in a local directory or Hub repository.
Parameters:
pretrained_model_name_or_path (`str` or `os.PathLike`, *optional*):
Can be either:
- A string, the *model id* (for example `google/ddpm-celebahq-256`) of a pretrained model hosted on
the Hub.
- A path to a *directory* (for example `./my_model_directory`) containing the scheduler
configuration saved with [`~SchedulerMixin.save_pretrained`].
subfolder (`str`, *optional*):
The subfolder location of a model file within a larger model repository on the Hub or locally.
return_unused_kwargs (`bool`, *optional*, defaults to `False`):
Whether kwargs that are not consumed by the Python class should be returned or not.
cache_dir (`Union[str, os.PathLike]`, *optional*):
Path to a directory where a downloaded pretrained model configuration is cached if the standard cache
is not used.
force_download (`bool`, *optional*, defaults to `False`):
Whether or not to force the (re-)download of the model weights and configuration files, overriding the
cached versions if they exist.
resume_download (`bool`, *optional*, defaults to `False`):
Whether or not to resume downloading the model weights and configuration files. If set to `False`, any
incompletely downloaded files are deleted.
proxies (`Dict[str, str]`, *optional*):
A dictionary of proxy servers to use by protocol or endpoint, for example, `{'http': 'foo.bar:3128',
'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
output_loading_info(`bool`, *optional*, defaults to `False`):
Whether or not to also return a dictionary containing missing keys, unexpected keys and error messages.
local_files_only(`bool`, *optional*, defaults to `False`):
Whether to only load local model weights and configuration files or not. If set to `True`, the model
won't be downloaded from the Hub.
use_auth_token (`str` or *bool*, *optional*):
The token to use as HTTP bearer authorization for remote files. If `True`, the token generated from
`diffusers-cli login` (stored in `~/.huggingface`) is used.
revision (`str`, *optional*, defaults to `"main"`):
The specific model version to use. It can be a branch name, a tag name, a commit id, or any identifier
allowed by Git.
<Tip>
To use private or [gated models](https://huggingface.co/docs/hub/models-gated#gated-models), log-in with
`huggingface-cli login`. You can also activate the special
["offline-mode"](https://huggingface.co/diffusers/installation.html#offline-mode) to use this method in a
firewalled environment.
</Tip>
"""
config, kwargs, commit_hash = cls.load_config(
pretrained_model_name_or_path=pretrained_model_name_or_path,
subfolder=subfolder,
return_unused_kwargs=True,
return_commit_hash=True,
**kwargs,
)
return cls.from_config(config, return_unused_kwargs=return_unused_kwargs, **kwargs)
def save_pretrained(self, save_directory: Union[str, os.PathLike], push_to_hub: bool = False, **kwargs):
"""
Save a scheduler configuration object to a directory so that it can be reloaded using the
[`~SchedulerMixin.from_pretrained`] class method.
Args:
save_directory (`str` or `os.PathLike`):
Directory where the configuration JSON file will be saved (will be created if it does not exist).
push_to_hub (`bool`, *optional*, defaults to `False`):
Whether or not to push your model to the Hugging Face Hub after saving it. You can specify the
repository you want to push to with `repo_id` (will default to the name of `save_directory` in your
namespace).
kwargs (`Dict[str, Any]`, *optional*):
Additional keyword arguments passed along to the [`~utils.PushToHubMixin.push_to_hub`] method.
"""
self.save_config(save_directory=save_directory, push_to_hub=push_to_hub, **kwargs)
@property
def compatibles(self):
"""
Returns all schedulers that are compatible with this scheduler
Returns:
`List[SchedulerMixin]`: List of compatible schedulers
"""
return self._get_compatibles()
@classmethod
def _get_compatibles(cls):
compatible_classes_str = list(set([cls.__name__] + cls._compatibles))
diffusers_library = importlib.import_module(__name__.split(".")[0])
compatible_classes = [
getattr(diffusers_library, c) for c in compatible_classes_str if hasattr(diffusers_library, c)
]
return compatible_classes
| diffusers-main | src/diffusers/schedulers/scheduling_utils.py |
# Copyright 2023 ParaDiGMS authors and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput
class DDPMParallelSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DDPMParallelScheduler(SchedulerMixin, ConfigMixin):
"""
Denoising diffusion probabilistic models (DDPMs) explores the connections between denoising score matching and
Langevin dynamics sampling.
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details, see the original paper: https://arxiv.org/abs/2006.11239
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
beta_start (`float`): the starting `beta` value of inference.
beta_end (`float`): the final `beta` value.
beta_schedule (`str`):
the beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, `squaredcos_cap_v2` or `sigmoid`.
trained_betas (`np.ndarray`, optional):
option to pass an array of betas directly to the constructor to bypass `beta_start`, `beta_end` etc.
variance_type (`str`):
options to clip the variance used when adding noise to the denoised sample. Choose from `fixed_small`,
`fixed_small_log`, `fixed_large`, `fixed_large_log`, `learned` or `learned_range`.
clip_sample (`bool`, default `True`):
option to clip predicted sample for numerical stability.
clip_sample_range (`float`, default `1.0`):
the maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
prediction_type (`str`, default `epsilon`, optional):
prediction type of the scheduler function, one of `epsilon` (predicting the noise of the diffusion
process), `sample` (directly predicting the noisy sample`) or `v_prediction` (see section 2.4
https://imagen.research.google/video/paper.pdf)
thresholding (`bool`, default `False`):
whether to use the "dynamic thresholding" method (introduced by Imagen, https://arxiv.org/abs/2205.11487).
Note that the thresholding method is unsuitable for latent-space diffusion models (such as
stable-diffusion).
dynamic_thresholding_ratio (`float`, default `0.995`):
the ratio for the dynamic thresholding method. Default is `0.995`, the same as Imagen
(https://arxiv.org/abs/2205.11487). Valid only when `thresholding=True`.
sample_max_value (`float`, default `1.0`):
the threshold value for dynamic thresholding. Valid only when `thresholding=True`.
timestep_spacing (`str`, default `"leading"`):
The way the timesteps should be scaled. Refer to Table 2. of [Common Diffusion Noise Schedules and Sample
Steps are Flawed](https://arxiv.org/abs/2305.08891) for more information.
steps_offset (`int`, default `0`):
an offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False`, to make the last step use step 0 for the previous alpha product, as done in
stable diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
_is_ode_scheduler = False
@register_to_config
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.__init__
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
variance_type: str = "fixed_small",
clip_sample: bool = True,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
clip_sample_range: float = 1.0,
sample_max_value: float = 1.0,
timestep_spacing: str = "leading",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
elif beta_schedule == "sigmoid":
# GeoDiff sigmoid schedule
betas = torch.linspace(-6, 6, num_train_timesteps)
self.betas = torch.sigmoid(betas) * (beta_end - beta_start) + beta_start
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
self.one = torch.tensor(1.0)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# setable values
self.custom_timesteps = False
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy())
self.variance_type = variance_type
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.scale_model_input
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.set_timesteps
def set_timesteps(
self,
num_inference_steps: Optional[int] = None,
device: Union[str, torch.device] = None,
timesteps: Optional[List[int]] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model. If used,
`timesteps` must be `None`.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
timesteps (`List[int]`, *optional*):
Custom timesteps used to support arbitrary spacing between timesteps. If `None`, then the default
timestep spacing strategy of equal spacing between timesteps is used. If `timesteps` is passed,
`num_inference_steps` must be `None`.
"""
if num_inference_steps is not None and timesteps is not None:
raise ValueError("Can only pass one of `num_inference_steps` or `custom_timesteps`.")
if timesteps is not None:
for i in range(1, len(timesteps)):
if timesteps[i] >= timesteps[i - 1]:
raise ValueError("`custom_timesteps` must be in descending order.")
if timesteps[0] >= self.config.num_train_timesteps:
raise ValueError(
f"`timesteps` must start before `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps}."
)
timesteps = np.array(timesteps, dtype=np.int64)
self.custom_timesteps = True
else:
if num_inference_steps > self.config.num_train_timesteps:
raise ValueError(
f"`num_inference_steps`: {num_inference_steps} cannot be larger than `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps} as the unet model trained with this scheduler can only handle"
f" maximal {self.config.num_train_timesteps} timesteps."
)
self.num_inference_steps = num_inference_steps
self.custom_timesteps = False
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps)
.round()[::-1]
.copy()
.astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.round(np.arange(self.config.num_train_timesteps, 0, -step_ratio)).astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
self.timesteps = torch.from_numpy(timesteps).to(device)
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._get_variance
def _get_variance(self, t, predicted_variance=None, variance_type=None):
prev_t = self.previous_timestep(t)
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_t] if prev_t >= 0 else self.one
current_beta_t = 1 - alpha_prod_t / alpha_prod_t_prev
# For t > 0, compute predicted variance βt (see formula (6) and (7) from https://arxiv.org/pdf/2006.11239.pdf)
# and sample from it to get previous sample
# x_{t-1} ~ N(pred_prev_sample, variance) == add variance to pred_sample
variance = (1 - alpha_prod_t_prev) / (1 - alpha_prod_t) * current_beta_t
# we always take the log of variance, so clamp it to ensure it's not 0
variance = torch.clamp(variance, min=1e-20)
if variance_type is None:
variance_type = self.config.variance_type
# hacks - were probably added for training stability
if variance_type == "fixed_small":
variance = variance
# for rl-diffuser https://arxiv.org/abs/2205.09991
elif variance_type == "fixed_small_log":
variance = torch.log(variance)
variance = torch.exp(0.5 * variance)
elif variance_type == "fixed_large":
variance = current_beta_t
elif variance_type == "fixed_large_log":
# Glide max_log
variance = torch.log(current_beta_t)
elif variance_type == "learned":
return predicted_variance
elif variance_type == "learned_range":
min_log = torch.log(variance)
max_log = torch.log(current_beta_t)
frac = (predicted_variance + 1) / 2
variance = frac * max_log + (1 - frac) * min_log
return variance
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
generator=None,
return_dict: bool = True,
) -> Union[DDPMParallelSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
current instance of sample being created by diffusion process.
generator: random number generator.
return_dict (`bool`): option for returning tuple rather than DDPMParallelSchedulerOutput class
Returns:
[`~schedulers.scheduling_utils.DDPMParallelSchedulerOutput`] or `tuple`:
[`~schedulers.scheduling_utils.DDPMParallelSchedulerOutput`] if `return_dict` is True, otherwise a `tuple`.
When returning a tuple, the first element is the sample tensor.
"""
t = timestep
prev_t = self.previous_timestep(t)
if model_output.shape[1] == sample.shape[1] * 2 and self.variance_type in ["learned", "learned_range"]:
model_output, predicted_variance = torch.split(model_output, sample.shape[1], dim=1)
else:
predicted_variance = None
# 1. compute alphas, betas
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_t] if prev_t >= 0 else self.one
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
current_alpha_t = alpha_prod_t / alpha_prod_t_prev
current_beta_t = 1 - current_alpha_t
# 2. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample` or"
" `v_prediction` for the DDPMScheduler."
)
# 3. Clip or threshold "predicted x_0"
if self.config.thresholding:
pred_original_sample = self._threshold_sample(pred_original_sample)
elif self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
# 4. Compute coefficients for pred_original_sample x_0 and current sample x_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_original_sample_coeff = (alpha_prod_t_prev ** (0.5) * current_beta_t) / beta_prod_t
current_sample_coeff = current_alpha_t ** (0.5) * beta_prod_t_prev / beta_prod_t
# 5. Compute predicted previous sample µ_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_prev_sample = pred_original_sample_coeff * pred_original_sample + current_sample_coeff * sample
# 6. Add noise
variance = 0
if t > 0:
device = model_output.device
variance_noise = randn_tensor(
model_output.shape, generator=generator, device=device, dtype=model_output.dtype
)
if self.variance_type == "fixed_small_log":
variance = self._get_variance(t, predicted_variance=predicted_variance) * variance_noise
elif self.variance_type == "learned_range":
variance = self._get_variance(t, predicted_variance=predicted_variance)
variance = torch.exp(0.5 * variance) * variance_noise
else:
variance = (self._get_variance(t, predicted_variance=predicted_variance) ** 0.5) * variance_noise
pred_prev_sample = pred_prev_sample + variance
if not return_dict:
return (pred_prev_sample,)
return DDPMParallelSchedulerOutput(prev_sample=pred_prev_sample, pred_original_sample=pred_original_sample)
def batch_step_no_noise(
self,
model_output: torch.FloatTensor,
timesteps: List[int],
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
Batched version of the `step` function, to be able to reverse the SDE for multiple samples/timesteps at once.
Also, does not add any noise to the predicted sample, which is necessary for parallel sampling where the noise
is pre-sampled by the pipeline.
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`): direct output from learned diffusion model.
timesteps (`List[int]`):
current discrete timesteps in the diffusion chain. This is now a list of integers.
sample (`torch.FloatTensor`):
current instance of sample being created by diffusion process.
Returns:
`torch.FloatTensor`: sample tensor at previous timestep.
"""
t = timesteps
num_inference_steps = self.num_inference_steps if self.num_inference_steps else self.config.num_train_timesteps
prev_t = t - self.config.num_train_timesteps // num_inference_steps
t = t.view(-1, *([1] * (model_output.ndim - 1)))
prev_t = prev_t.view(-1, *([1] * (model_output.ndim - 1)))
if model_output.shape[1] == sample.shape[1] * 2 and self.variance_type in ["learned", "learned_range"]:
model_output, predicted_variance = torch.split(model_output, sample.shape[1], dim=1)
else:
pass
# 1. compute alphas, betas
self.alphas_cumprod = self.alphas_cumprod.to(model_output.device)
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[torch.clip(prev_t, min=0)]
alpha_prod_t_prev[prev_t < 0] = torch.tensor(1.0)
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
current_alpha_t = alpha_prod_t / alpha_prod_t_prev
current_beta_t = 1 - current_alpha_t
# 2. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample` or"
" `v_prediction` for the DDPMParallelScheduler."
)
# 3. Clip or threshold "predicted x_0"
if self.config.thresholding:
pred_original_sample = self._threshold_sample(pred_original_sample)
elif self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
# 4. Compute coefficients for pred_original_sample x_0 and current sample x_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_original_sample_coeff = (alpha_prod_t_prev ** (0.5) * current_beta_t) / beta_prod_t
current_sample_coeff = current_alpha_t ** (0.5) * beta_prod_t_prev / beta_prod_t
# 5. Compute predicted previous sample µ_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_prev_sample = pred_original_sample_coeff * pred_original_sample + current_sample_coeff * sample
return pred_prev_sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.get_velocity
def get_velocity(
self, sample: torch.FloatTensor, noise: torch.FloatTensor, timesteps: torch.IntTensor
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as sample
alphas_cumprod = self.alphas_cumprod.to(device=sample.device, dtype=sample.dtype)
timesteps = timesteps.to(sample.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(sample.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(sample.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
velocity = sqrt_alpha_prod * noise - sqrt_one_minus_alpha_prod * sample
return velocity
def __len__(self):
return self.config.num_train_timesteps
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.previous_timestep
def previous_timestep(self, timestep):
if self.custom_timesteps:
index = (self.timesteps == timestep).nonzero(as_tuple=True)[0][0]
if index == self.timesteps.shape[0] - 1:
prev_t = torch.tensor(-1)
else:
prev_t = self.timesteps[index + 1]
else:
num_inference_steps = (
self.num_inference_steps if self.num_inference_steps else self.config.num_train_timesteps
)
prev_t = timestep - self.config.num_train_timesteps // num_inference_steps
return prev_t
| diffusers-main | src/diffusers/schedulers/scheduling_ddpm_parallel.py |
# Copyright 2023 ParaDiGMS authors and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This code is strongly influenced by https://github.com/pesser/pytorch_diffusion
# and https://github.com/hojonathanho/diffusion
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput
class DDIMParallelSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
# Copied from diffusers.schedulers.scheduling_ddim.rescale_zero_terminal_snr
def rescale_zero_terminal_snr(betas):
"""
Rescales betas to have zero terminal SNR Based on https://arxiv.org/pdf/2305.08891.pdf (Algorithm 1)
Args:
betas (`torch.FloatTensor`):
the betas that the scheduler is being initialized with.
Returns:
`torch.FloatTensor`: rescaled betas with zero terminal SNR
"""
# Convert betas to alphas_bar_sqrt
alphas = 1.0 - betas
alphas_cumprod = torch.cumprod(alphas, dim=0)
alphas_bar_sqrt = alphas_cumprod.sqrt()
# Store old values.
alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
# Shift so the last timestep is zero.
alphas_bar_sqrt -= alphas_bar_sqrt_T
# Scale so the first timestep is back to the old value.
alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
# Convert alphas_bar_sqrt to betas
alphas_bar = alphas_bar_sqrt**2 # Revert sqrt
alphas = alphas_bar[1:] / alphas_bar[:-1] # Revert cumprod
alphas = torch.cat([alphas_bar[0:1], alphas])
betas = 1 - alphas
return betas
class DDIMParallelScheduler(SchedulerMixin, ConfigMixin):
"""
Denoising diffusion implicit models is a scheduler that extends the denoising procedure introduced in denoising
diffusion probabilistic models (DDPMs) with non-Markovian guidance.
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details, see the original paper: https://arxiv.org/abs/2010.02502
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
beta_start (`float`): the starting `beta` value of inference.
beta_end (`float`): the final `beta` value.
beta_schedule (`str`):
the beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, optional):
option to pass an array of betas directly to the constructor to bypass `beta_start`, `beta_end` etc.
clip_sample (`bool`, default `True`):
option to clip predicted sample for numerical stability.
clip_sample_range (`float`, default `1.0`):
the maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
set_alpha_to_one (`bool`, default `True`):
each diffusion step uses the value of alphas product at that step and at the previous one. For the final
step there is no previous alpha. When this option is `True` the previous alpha product is fixed to `1`,
otherwise it uses the value of alpha at step 0.
steps_offset (`int`, default `0`):
an offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False`, to make the last step use step 0 for the previous alpha product, as done in
stable diffusion.
prediction_type (`str`, default `epsilon`, optional):
prediction type of the scheduler function, one of `epsilon` (predicting the noise of the diffusion
process), `sample` (directly predicting the noisy sample`) or `v_prediction` (see section 2.4
https://imagen.research.google/video/paper.pdf)
thresholding (`bool`, default `False`):
whether to use the "dynamic thresholding" method (introduced by Imagen, https://arxiv.org/abs/2205.11487).
Note that the thresholding method is unsuitable for latent-space diffusion models (such as
stable-diffusion).
dynamic_thresholding_ratio (`float`, default `0.995`):
the ratio for the dynamic thresholding method. Default is `0.995`, the same as Imagen
(https://arxiv.org/abs/2205.11487). Valid only when `thresholding=True`.
sample_max_value (`float`, default `1.0`):
the threshold value for dynamic thresholding. Valid only when `thresholding=True`.
timestep_spacing (`str`, default `"leading"`):
The way the timesteps should be scaled. Refer to Table 2. of [Common Diffusion Noise Schedules and Sample
Steps are Flawed](https://arxiv.org/abs/2305.08891) for more information.
rescale_betas_zero_snr (`bool`, default `False`):
whether to rescale the betas to have zero terminal SNR (proposed by https://arxiv.org/pdf/2305.08891.pdf).
This can enable the model to generate very bright and dark samples instead of limiting it to samples with
medium brightness. Loosely related to
[`--offset_noise`](https://github.com/huggingface/diffusers/blob/74fd735eb073eb1d774b1ab4154a0876eb82f055/examples/dreambooth/train_dreambooth.py#L506).
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
_is_ode_scheduler = True
@register_to_config
# Copied from diffusers.schedulers.scheduling_ddim.DDIMScheduler.__init__
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
clip_sample: bool = True,
set_alpha_to_one: bool = True,
steps_offset: int = 0,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
clip_sample_range: float = 1.0,
sample_max_value: float = 1.0,
timestep_spacing: str = "leading",
rescale_betas_zero_snr: bool = False,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
# Rescale for zero SNR
if rescale_betas_zero_snr:
self.betas = rescale_zero_terminal_snr(self.betas)
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# At every step in ddim, we are looking into the previous alphas_cumprod
# For the final step, there is no previous alphas_cumprod because we are already at 0
# `set_alpha_to_one` decides whether we set this parameter simply to one or
# whether we use the final alpha of the "non-previous" one.
self.final_alpha_cumprod = torch.tensor(1.0) if set_alpha_to_one else self.alphas_cumprod[0]
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# setable values
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy().astype(np.int64))
# Copied from diffusers.schedulers.scheduling_ddim.DDIMScheduler.scale_model_input
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def _get_variance(self, timestep, prev_timestep=None):
if prev_timestep is None:
prev_timestep = timestep - self.config.num_train_timesteps // self.num_inference_steps
alpha_prod_t = self.alphas_cumprod[timestep]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.final_alpha_cumprod
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
variance = (beta_prod_t_prev / beta_prod_t) * (1 - alpha_prod_t / alpha_prod_t_prev)
return variance
def _batch_get_variance(self, t, prev_t):
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[torch.clip(prev_t, min=0)]
alpha_prod_t_prev[prev_t < 0] = torch.tensor(1.0)
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
variance = (beta_prod_t_prev / beta_prod_t) * (1 - alpha_prod_t / alpha_prod_t_prev)
return variance
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
# Copied from diffusers.schedulers.scheduling_ddim.DDIMScheduler.set_timesteps
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
"""
if num_inference_steps > self.config.num_train_timesteps:
raise ValueError(
f"`num_inference_steps`: {num_inference_steps} cannot be larger than `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps} as the unet model trained with this scheduler can only handle"
f" maximal {self.config.num_train_timesteps} timesteps."
)
self.num_inference_steps = num_inference_steps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps)
.round()[::-1]
.copy()
.astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.round(np.arange(self.config.num_train_timesteps, 0, -step_ratio)).astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'leading' or 'trailing'."
)
self.timesteps = torch.from_numpy(timesteps).to(device)
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
eta: float = 0.0,
use_clipped_model_output: bool = False,
generator=None,
variance_noise: Optional[torch.FloatTensor] = None,
return_dict: bool = True,
) -> Union[DDIMParallelSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
current instance of sample being created by diffusion process.
eta (`float`): weight of noise for added noise in diffusion step.
use_clipped_model_output (`bool`): if `True`, compute "corrected" `model_output` from the clipped
predicted original sample. Necessary because predicted original sample is clipped to [-1, 1] when
`self.config.clip_sample` is `True`. If no clipping has happened, "corrected" `model_output` would
coincide with the one provided as input and `use_clipped_model_output` will have not effect.
generator: random number generator.
variance_noise (`torch.FloatTensor`): instead of generating noise for the variance using `generator`, we
can directly provide the noise for the variance itself. This is useful for methods such as
CycleDiffusion. (https://arxiv.org/abs/2210.05559)
return_dict (`bool`): option for returning tuple rather than DDIMParallelSchedulerOutput class
Returns:
[`~schedulers.scheduling_utils.DDIMParallelSchedulerOutput`] or `tuple`:
[`~schedulers.scheduling_utils.DDIMParallelSchedulerOutput`] if `return_dict` is True, otherwise a `tuple`.
When returning a tuple, the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
# See formulas (12) and (16) of DDIM paper https://arxiv.org/pdf/2010.02502.pdf
# Ideally, read DDIM paper in-detail understanding
# Notation (<variable name> -> <name in paper>
# - pred_noise_t -> e_theta(x_t, t)
# - pred_original_sample -> f_theta(x_t, t) or x_0
# - std_dev_t -> sigma_t
# - eta -> η
# - pred_sample_direction -> "direction pointing to x_t"
# - pred_prev_sample -> "x_t-1"
# 1. get previous step value (=t-1)
prev_timestep = timestep - self.config.num_train_timesteps // self.num_inference_steps
# 2. compute alphas, betas
alpha_prod_t = self.alphas_cumprod[timestep]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.final_alpha_cumprod
beta_prod_t = 1 - alpha_prod_t
# 3. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
pred_epsilon = model_output
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
pred_epsilon = (alpha_prod_t**0.5) * model_output + (beta_prod_t**0.5) * sample
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction`"
)
# 4. Clip or threshold "predicted x_0"
if self.config.thresholding:
pred_original_sample = self._threshold_sample(pred_original_sample)
elif self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
# 5. compute variance: "sigma_t(η)" -> see formula (16)
# σ_t = sqrt((1 − α_t−1)/(1 − α_t)) * sqrt(1 − α_t/α_t−1)
variance = self._get_variance(timestep, prev_timestep)
std_dev_t = eta * variance ** (0.5)
if use_clipped_model_output:
# the pred_epsilon is always re-derived from the clipped x_0 in Glide
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
# 6. compute "direction pointing to x_t" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
pred_sample_direction = (1 - alpha_prod_t_prev - std_dev_t**2) ** (0.5) * pred_epsilon
# 7. compute x_t without "random noise" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
prev_sample = alpha_prod_t_prev ** (0.5) * pred_original_sample + pred_sample_direction
if eta > 0:
if variance_noise is not None and generator is not None:
raise ValueError(
"Cannot pass both generator and variance_noise. Please make sure that either `generator` or"
" `variance_noise` stays `None`."
)
if variance_noise is None:
variance_noise = randn_tensor(
model_output.shape, generator=generator, device=model_output.device, dtype=model_output.dtype
)
variance = std_dev_t * variance_noise
prev_sample = prev_sample + variance
if not return_dict:
return (prev_sample,)
return DDIMParallelSchedulerOutput(prev_sample=prev_sample, pred_original_sample=pred_original_sample)
def batch_step_no_noise(
self,
model_output: torch.FloatTensor,
timesteps: List[int],
sample: torch.FloatTensor,
eta: float = 0.0,
use_clipped_model_output: bool = False,
) -> torch.FloatTensor:
"""
Batched version of the `step` function, to be able to reverse the SDE for multiple samples/timesteps at once.
Also, does not add any noise to the predicted sample, which is necessary for parallel sampling where the noise
is pre-sampled by the pipeline.
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`): direct output from learned diffusion model.
timesteps (`List[int]`):
current discrete timesteps in the diffusion chain. This is now a list of integers.
sample (`torch.FloatTensor`):
current instance of sample being created by diffusion process.
eta (`float`): weight of noise for added noise in diffusion step.
use_clipped_model_output (`bool`): if `True`, compute "corrected" `model_output` from the clipped
predicted original sample. Necessary because predicted original sample is clipped to [-1, 1] when
`self.config.clip_sample` is `True`. If no clipping has happened, "corrected" `model_output` would
coincide with the one provided as input and `use_clipped_model_output` will have not effect.
Returns:
`torch.FloatTensor`: sample tensor at previous timestep.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
assert eta == 0.0
# See formulas (12) and (16) of DDIM paper https://arxiv.org/pdf/2010.02502.pdf
# Ideally, read DDIM paper in-detail understanding
# Notation (<variable name> -> <name in paper>
# - pred_noise_t -> e_theta(x_t, t)
# - pred_original_sample -> f_theta(x_t, t) or x_0
# - std_dev_t -> sigma_t
# - eta -> η
# - pred_sample_direction -> "direction pointing to x_t"
# - pred_prev_sample -> "x_t-1"
# 1. get previous step value (=t-1)
t = timesteps
prev_t = t - self.config.num_train_timesteps // self.num_inference_steps
t = t.view(-1, *([1] * (model_output.ndim - 1)))
prev_t = prev_t.view(-1, *([1] * (model_output.ndim - 1)))
# 1. compute alphas, betas
self.alphas_cumprod = self.alphas_cumprod.to(model_output.device)
self.final_alpha_cumprod = self.final_alpha_cumprod.to(model_output.device)
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[torch.clip(prev_t, min=0)]
alpha_prod_t_prev[prev_t < 0] = torch.tensor(1.0)
beta_prod_t = 1 - alpha_prod_t
# 3. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
pred_epsilon = model_output
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
pred_epsilon = (alpha_prod_t**0.5) * model_output + (beta_prod_t**0.5) * sample
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction`"
)
# 4. Clip or threshold "predicted x_0"
if self.config.thresholding:
pred_original_sample = self._threshold_sample(pred_original_sample)
elif self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
# 5. compute variance: "sigma_t(η)" -> see formula (16)
# σ_t = sqrt((1 − α_t−1)/(1 − α_t)) * sqrt(1 − α_t/α_t−1)
variance = self._batch_get_variance(t, prev_t).to(model_output.device).view(*alpha_prod_t_prev.shape)
std_dev_t = eta * variance ** (0.5)
if use_clipped_model_output:
# the pred_epsilon is always re-derived from the clipped x_0 in Glide
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
# 6. compute "direction pointing to x_t" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
pred_sample_direction = (1 - alpha_prod_t_prev - std_dev_t**2) ** (0.5) * pred_epsilon
# 7. compute x_t without "random noise" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
prev_sample = alpha_prod_t_prev ** (0.5) * pred_original_sample + pred_sample_direction
return prev_sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.get_velocity
def get_velocity(
self, sample: torch.FloatTensor, noise: torch.FloatTensor, timesteps: torch.IntTensor
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as sample
alphas_cumprod = self.alphas_cumprod.to(device=sample.device, dtype=sample.dtype)
timesteps = timesteps.to(sample.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(sample.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(sample.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
velocity = sqrt_alpha_prod * noise - sqrt_one_minus_alpha_prod * sample
return velocity
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_ddim_parallel.py |
# Copyright (c) 2022 Pablo Pernías MIT License
# Copyright 2023 UC Berkeley Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import SchedulerMixin
@dataclass
class DDPMWuerstchenSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's step function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
"""
prev_sample: torch.FloatTensor
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DDPMWuerstchenScheduler(SchedulerMixin, ConfigMixin):
"""
Denoising diffusion probabilistic models (DDPMs) explores the connections between denoising score matching and
Langevin dynamics sampling.
[`~ConfigMixin`] takes care of storing all config attributes that are passed in the scheduler's `__init__`
function, such as `num_train_timesteps`. They can be accessed via `scheduler.config.num_train_timesteps`.
[`SchedulerMixin`] provides general loading and saving functionality via the [`SchedulerMixin.save_pretrained`] and
[`~SchedulerMixin.from_pretrained`] functions.
For more details, see the original paper: https://arxiv.org/abs/2006.11239
Args:
scaler (`float`): ....
s (`float`): ....
"""
@register_to_config
def __init__(
self,
scaler: float = 1.0,
s: float = 0.008,
):
self.scaler = scaler
self.s = torch.tensor([s])
self._init_alpha_cumprod = torch.cos(self.s / (1 + self.s) * torch.pi * 0.5) ** 2
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
def _alpha_cumprod(self, t, device):
if self.scaler > 1:
t = 1 - (1 - t) ** self.scaler
elif self.scaler < 1:
t = t**self.scaler
alpha_cumprod = torch.cos(
(t + self.s.to(device)) / (1 + self.s.to(device)) * torch.pi * 0.5
) ** 2 / self._init_alpha_cumprod.to(device)
return alpha_cumprod.clamp(0.0001, 0.9999)
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`): input sample
timestep (`int`, optional): current timestep
Returns:
`torch.FloatTensor`: scaled input sample
"""
return sample
def set_timesteps(
self,
num_inference_steps: int = None,
timesteps: Optional[List[int]] = None,
device: Union[str, torch.device] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference.
Args:
num_inference_steps (`Dict[float, int]`):
the number of diffusion steps used when generating samples with a pre-trained model. If passed, then
`timesteps` must be `None`.
device (`str` or `torch.device`, optional):
the device to which the timesteps are moved to. {2 / 3: 20, 0.0: 10}
"""
if timesteps is None:
timesteps = torch.linspace(1.0, 0.0, num_inference_steps + 1, device=device)
if not isinstance(timesteps, torch.Tensor):
timesteps = torch.Tensor(timesteps).to(device)
self.timesteps = timesteps
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
generator=None,
return_dict: bool = True,
) -> Union[DDPMWuerstchenSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
current instance of sample being created by diffusion process.
generator: random number generator.
return_dict (`bool`): option for returning tuple rather than DDPMWuerstchenSchedulerOutput class
Returns:
[`DDPMWuerstchenSchedulerOutput`] or `tuple`: [`DDPMWuerstchenSchedulerOutput`] if `return_dict` is True,
otherwise a `tuple`. When returning a tuple, the first element is the sample tensor.
"""
dtype = model_output.dtype
device = model_output.device
t = timestep
prev_t = self.previous_timestep(t)
alpha_cumprod = self._alpha_cumprod(t, device).view(t.size(0), *[1 for _ in sample.shape[1:]])
alpha_cumprod_prev = self._alpha_cumprod(prev_t, device).view(prev_t.size(0), *[1 for _ in sample.shape[1:]])
alpha = alpha_cumprod / alpha_cumprod_prev
mu = (1.0 / alpha).sqrt() * (sample - (1 - alpha) * model_output / (1 - alpha_cumprod).sqrt())
std_noise = randn_tensor(mu.shape, generator=generator, device=model_output.device, dtype=model_output.dtype)
std = ((1 - alpha) * (1.0 - alpha_cumprod_prev) / (1.0 - alpha_cumprod)).sqrt() * std_noise
pred = mu + std * (prev_t != 0).float().view(prev_t.size(0), *[1 for _ in sample.shape[1:]])
if not return_dict:
return (pred.to(dtype),)
return DDPMWuerstchenSchedulerOutput(prev_sample=pred.to(dtype))
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
def previous_timestep(self, timestep):
index = (self.timesteps - timestep[0]).abs().argmin().item()
prev_t = self.timesteps[index + 1][None].expand(timestep.shape[0])
return prev_t
| diffusers-main | src/diffusers/schedulers/scheduling_ddpm_wuerstchen.py |
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import importlib
import math
import os
from dataclasses import dataclass
from enum import Enum
from typing import Any, Dict, Optional, Tuple, Union
import flax
import jax.numpy as jnp
from ..utils import BaseOutput, PushToHubMixin
SCHEDULER_CONFIG_NAME = "scheduler_config.json"
# NOTE: We make this type an enum because it simplifies usage in docs and prevents
# circular imports when used for `_compatibles` within the schedulers module.
# When it's used as a type in pipelines, it really is a Union because the actual
# scheduler instance is passed in.
class FlaxKarrasDiffusionSchedulers(Enum):
FlaxDDIMScheduler = 1
FlaxDDPMScheduler = 2
FlaxPNDMScheduler = 3
FlaxLMSDiscreteScheduler = 4
FlaxDPMSolverMultistepScheduler = 5
@dataclass
class FlaxSchedulerOutput(BaseOutput):
"""
Base class for the scheduler's step function output.
Args:
prev_sample (`jnp.ndarray` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
"""
prev_sample: jnp.ndarray
class FlaxSchedulerMixin(PushToHubMixin):
"""
Mixin containing common functions for the schedulers.
Class attributes:
- **_compatibles** (`List[str]`) -- A list of classes that are compatible with the parent class, so that
`from_config` can be used from a class different than the one used to save the config (should be overridden
by parent class).
"""
config_name = SCHEDULER_CONFIG_NAME
ignore_for_config = ["dtype"]
_compatibles = []
has_compatibles = True
@classmethod
def from_pretrained(
cls,
pretrained_model_name_or_path: Dict[str, Any] = None,
subfolder: Optional[str] = None,
return_unused_kwargs=False,
**kwargs,
):
r"""
Instantiate a Scheduler class from a pre-defined JSON-file.
Parameters:
pretrained_model_name_or_path (`str` or `os.PathLike`, *optional*):
Can be either:
- A string, the *model id* of a model repo on huggingface.co. Valid model ids should have an
organization name, like `google/ddpm-celebahq-256`.
- A path to a *directory* containing model weights saved using [`~SchedulerMixin.save_pretrained`],
e.g., `./my_model_directory/`.
subfolder (`str`, *optional*):
In case the relevant files are located inside a subfolder of the model repo (either remote in
huggingface.co or downloaded locally), you can specify the folder name here.
return_unused_kwargs (`bool`, *optional*, defaults to `False`):
Whether kwargs that are not consumed by the Python class should be returned or not.
cache_dir (`Union[str, os.PathLike]`, *optional*):
Path to a directory in which a downloaded pretrained model configuration should be cached if the
standard cache should not be used.
force_download (`bool`, *optional*, defaults to `False`):
Whether or not to force the (re-)download of the model weights and configuration files, overriding the
cached versions if they exist.
resume_download (`bool`, *optional*, defaults to `False`):
Whether or not to delete incompletely received files. Will attempt to resume the download if such a
file exists.
proxies (`Dict[str, str]`, *optional*):
A dictionary of proxy servers to use by protocol or endpoint, e.g., `{'http': 'foo.bar:3128',
'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
output_loading_info(`bool`, *optional*, defaults to `False`):
Whether or not to also return a dictionary containing missing keys, unexpected keys and error messages.
local_files_only(`bool`, *optional*, defaults to `False`):
Whether or not to only look at local files (i.e., do not try to download the model).
use_auth_token (`str` or *bool*, *optional*):
The token to use as HTTP bearer authorization for remote files. If `True`, will use the token generated
when running `transformers-cli login` (stored in `~/.huggingface`).
revision (`str`, *optional*, defaults to `"main"`):
The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
git-based system for storing models and other artifacts on huggingface.co, so `revision` can be any
identifier allowed by git.
<Tip>
It is required to be logged in (`huggingface-cli login`) when you want to use private or [gated
models](https://huggingface.co/docs/hub/models-gated#gated-models).
</Tip>
<Tip>
Activate the special ["offline-mode"](https://huggingface.co/transformers/installation.html#offline-mode) to
use this method in a firewalled environment.
</Tip>
"""
config, kwargs = cls.load_config(
pretrained_model_name_or_path=pretrained_model_name_or_path,
subfolder=subfolder,
return_unused_kwargs=True,
**kwargs,
)
scheduler, unused_kwargs = cls.from_config(config, return_unused_kwargs=True, **kwargs)
if hasattr(scheduler, "create_state") and getattr(scheduler, "has_state", False):
state = scheduler.create_state()
if return_unused_kwargs:
return scheduler, state, unused_kwargs
return scheduler, state
def save_pretrained(self, save_directory: Union[str, os.PathLike], push_to_hub: bool = False, **kwargs):
"""
Save a scheduler configuration object to the directory `save_directory`, so that it can be re-loaded using the
[`~FlaxSchedulerMixin.from_pretrained`] class method.
Args:
save_directory (`str` or `os.PathLike`):
Directory where the configuration JSON file will be saved (will be created if it does not exist).
push_to_hub (`bool`, *optional*, defaults to `False`):
Whether or not to push your model to the Hugging Face Hub after saving it. You can specify the
repository you want to push to with `repo_id` (will default to the name of `save_directory` in your
namespace).
kwargs (`Dict[str, Any]`, *optional*):
Additional keyword arguments passed along to the [`~utils.PushToHubMixin.push_to_hub`] method.
"""
self.save_config(save_directory=save_directory, push_to_hub=push_to_hub, **kwargs)
@property
def compatibles(self):
"""
Returns all schedulers that are compatible with this scheduler
Returns:
`List[SchedulerMixin]`: List of compatible schedulers
"""
return self._get_compatibles()
@classmethod
def _get_compatibles(cls):
compatible_classes_str = list(set([cls.__name__] + cls._compatibles))
diffusers_library = importlib.import_module(__name__.split(".")[0])
compatible_classes = [
getattr(diffusers_library, c) for c in compatible_classes_str if hasattr(diffusers_library, c)
]
return compatible_classes
def broadcast_to_shape_from_left(x: jnp.ndarray, shape: Tuple[int]) -> jnp.ndarray:
assert len(shape) >= x.ndim
return jnp.broadcast_to(x.reshape(x.shape + (1,) * (len(shape) - x.ndim)), shape)
def betas_for_alpha_bar(num_diffusion_timesteps: int, max_beta=0.999, dtype=jnp.float32) -> jnp.ndarray:
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
Returns:
betas (`jnp.ndarray`): the betas used by the scheduler to step the model outputs
"""
def alpha_bar(time_step):
return math.cos((time_step + 0.008) / 1.008 * math.pi / 2) ** 2
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar(t2) / alpha_bar(t1), max_beta))
return jnp.array(betas, dtype=dtype)
@flax.struct.dataclass
class CommonSchedulerState:
alphas: jnp.ndarray
betas: jnp.ndarray
alphas_cumprod: jnp.ndarray
@classmethod
def create(cls, scheduler):
config = scheduler.config
if config.trained_betas is not None:
betas = jnp.asarray(config.trained_betas, dtype=scheduler.dtype)
elif config.beta_schedule == "linear":
betas = jnp.linspace(config.beta_start, config.beta_end, config.num_train_timesteps, dtype=scheduler.dtype)
elif config.beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
betas = (
jnp.linspace(
config.beta_start**0.5, config.beta_end**0.5, config.num_train_timesteps, dtype=scheduler.dtype
)
** 2
)
elif config.beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
betas = betas_for_alpha_bar(config.num_train_timesteps, dtype=scheduler.dtype)
else:
raise NotImplementedError(
f"beta_schedule {config.beta_schedule} is not implemented for scheduler {scheduler.__class__.__name__}"
)
alphas = 1.0 - betas
alphas_cumprod = jnp.cumprod(alphas, axis=0)
return cls(
alphas=alphas,
betas=betas,
alphas_cumprod=alphas_cumprod,
)
def get_sqrt_alpha_prod(
state: CommonSchedulerState, original_samples: jnp.ndarray, noise: jnp.ndarray, timesteps: jnp.ndarray
):
alphas_cumprod = state.alphas_cumprod
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
sqrt_alpha_prod = broadcast_to_shape_from_left(sqrt_alpha_prod, original_samples.shape)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
sqrt_one_minus_alpha_prod = broadcast_to_shape_from_left(sqrt_one_minus_alpha_prod, original_samples.shape)
return sqrt_alpha_prod, sqrt_one_minus_alpha_prod
def add_noise_common(
state: CommonSchedulerState, original_samples: jnp.ndarray, noise: jnp.ndarray, timesteps: jnp.ndarray
):
sqrt_alpha_prod, sqrt_one_minus_alpha_prod = get_sqrt_alpha_prod(state, original_samples, noise, timesteps)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def get_velocity_common(state: CommonSchedulerState, sample: jnp.ndarray, noise: jnp.ndarray, timesteps: jnp.ndarray):
sqrt_alpha_prod, sqrt_one_minus_alpha_prod = get_sqrt_alpha_prod(state, sample, noise, timesteps)
velocity = sqrt_alpha_prod * noise - sqrt_one_minus_alpha_prod * sample
return velocity
| diffusers-main | src/diffusers/schedulers/scheduling_utils_flax.py |
# Copyright 2023 Google Brain and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/yang-song/score_sde_pytorch
import math
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import SchedulerMixin, SchedulerOutput
@dataclass
class SdeVeOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
prev_sample_mean (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Mean averaged `prev_sample` over previous timesteps.
"""
prev_sample: torch.FloatTensor
prev_sample_mean: torch.FloatTensor
class ScoreSdeVeScheduler(SchedulerMixin, ConfigMixin):
"""
`ScoreSdeVeScheduler` is a variance exploding stochastic differential equation (SDE) scheduler.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
snr (`float`, defaults to 0.15):
A coefficient weighting the step from the `model_output` sample (from the network) to the random noise.
sigma_min (`float`, defaults to 0.01):
The initial noise scale for the sigma sequence in the sampling procedure. The minimum sigma should mirror
the distribution of the data.
sigma_max (`float`, defaults to 1348.0):
The maximum value used for the range of continuous timesteps passed into the model.
sampling_eps (`float`, defaults to 1e-5):
The end value of sampling where timesteps decrease progressively from 1 to epsilon.
correct_steps (`int`, defaults to 1):
The number of correction steps performed on a produced sample.
"""
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 2000,
snr: float = 0.15,
sigma_min: float = 0.01,
sigma_max: float = 1348.0,
sampling_eps: float = 1e-5,
correct_steps: int = 1,
):
# standard deviation of the initial noise distribution
self.init_noise_sigma = sigma_max
# setable values
self.timesteps = None
self.set_sigmas(num_train_timesteps, sigma_min, sigma_max, sampling_eps)
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def set_timesteps(
self, num_inference_steps: int, sampling_eps: float = None, device: Union[str, torch.device] = None
):
"""
Sets the continuous timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
sampling_eps (`float`, *optional*):
The final timestep value (overrides value given during scheduler instantiation).
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
sampling_eps = sampling_eps if sampling_eps is not None else self.config.sampling_eps
self.timesteps = torch.linspace(1, sampling_eps, num_inference_steps, device=device)
def set_sigmas(
self, num_inference_steps: int, sigma_min: float = None, sigma_max: float = None, sampling_eps: float = None
):
"""
Sets the noise scales used for the diffusion chain (to be run before inference). The sigmas control the weight
of the `drift` and `diffusion` components of the sample update.
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
sigma_min (`float`, optional):
The initial noise scale value (overrides value given during scheduler instantiation).
sigma_max (`float`, optional):
The final noise scale value (overrides value given during scheduler instantiation).
sampling_eps (`float`, optional):
The final timestep value (overrides value given during scheduler instantiation).
"""
sigma_min = sigma_min if sigma_min is not None else self.config.sigma_min
sigma_max = sigma_max if sigma_max is not None else self.config.sigma_max
sampling_eps = sampling_eps if sampling_eps is not None else self.config.sampling_eps
if self.timesteps is None:
self.set_timesteps(num_inference_steps, sampling_eps)
self.sigmas = sigma_min * (sigma_max / sigma_min) ** (self.timesteps / sampling_eps)
self.discrete_sigmas = torch.exp(torch.linspace(math.log(sigma_min), math.log(sigma_max), num_inference_steps))
self.sigmas = torch.tensor([sigma_min * (sigma_max / sigma_min) ** t for t in self.timesteps])
def get_adjacent_sigma(self, timesteps, t):
return torch.where(
timesteps == 0,
torch.zeros_like(t.to(timesteps.device)),
self.discrete_sigmas[timesteps - 1].to(timesteps.device),
)
def step_pred(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[SdeVeOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_sde_ve.SdeVeOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_sde_ve.SdeVeOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_sde_ve.SdeVeOutput`] is returned, otherwise a tuple
is returned where the first element is the sample tensor.
"""
if self.timesteps is None:
raise ValueError(
"`self.timesteps` is not set, you need to run 'set_timesteps' after creating the scheduler"
)
timestep = timestep * torch.ones(
sample.shape[0], device=sample.device
) # torch.repeat_interleave(timestep, sample.shape[0])
timesteps = (timestep * (len(self.timesteps) - 1)).long()
# mps requires indices to be in the same device, so we use cpu as is the default with cuda
timesteps = timesteps.to(self.discrete_sigmas.device)
sigma = self.discrete_sigmas[timesteps].to(sample.device)
adjacent_sigma = self.get_adjacent_sigma(timesteps, timestep).to(sample.device)
drift = torch.zeros_like(sample)
diffusion = (sigma**2 - adjacent_sigma**2) ** 0.5
# equation 6 in the paper: the model_output modeled by the network is grad_x log pt(x)
# also equation 47 shows the analog from SDE models to ancestral sampling methods
diffusion = diffusion.flatten()
while len(diffusion.shape) < len(sample.shape):
diffusion = diffusion.unsqueeze(-1)
drift = drift - diffusion**2 * model_output
# equation 6: sample noise for the diffusion term of
noise = randn_tensor(
sample.shape, layout=sample.layout, generator=generator, device=sample.device, dtype=sample.dtype
)
prev_sample_mean = sample - drift # subtract because `dt` is a small negative timestep
# TODO is the variable diffusion the correct scaling term for the noise?
prev_sample = prev_sample_mean + diffusion * noise # add impact of diffusion field g
if not return_dict:
return (prev_sample, prev_sample_mean)
return SdeVeOutput(prev_sample=prev_sample, prev_sample_mean=prev_sample_mean)
def step_correct(
self,
model_output: torch.FloatTensor,
sample: torch.FloatTensor,
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Correct the predicted sample based on the `model_output` of the network. This is often run repeatedly after
making the prediction for the previous timestep.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_sde_ve.SdeVeOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_sde_ve.SdeVeOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_sde_ve.SdeVeOutput`] is returned, otherwise a tuple
is returned where the first element is the sample tensor.
"""
if self.timesteps is None:
raise ValueError(
"`self.timesteps` is not set, you need to run 'set_timesteps' after creating the scheduler"
)
# For small batch sizes, the paper "suggest replacing norm(z) with sqrt(d), where d is the dim. of z"
# sample noise for correction
noise = randn_tensor(sample.shape, layout=sample.layout, generator=generator).to(sample.device)
# compute step size from the model_output, the noise, and the snr
grad_norm = torch.norm(model_output.reshape(model_output.shape[0], -1), dim=-1).mean()
noise_norm = torch.norm(noise.reshape(noise.shape[0], -1), dim=-1).mean()
step_size = (self.config.snr * noise_norm / grad_norm) ** 2 * 2
step_size = step_size * torch.ones(sample.shape[0]).to(sample.device)
# self.repeat_scalar(step_size, sample.shape[0])
# compute corrected sample: model_output term and noise term
step_size = step_size.flatten()
while len(step_size.shape) < len(sample.shape):
step_size = step_size.unsqueeze(-1)
prev_sample_mean = sample + step_size * model_output
prev_sample = prev_sample_mean + ((step_size * 2) ** 0.5) * noise
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.FloatTensor,
) -> torch.FloatTensor:
# Make sure sigmas and timesteps have the same device and dtype as original_samples
timesteps = timesteps.to(original_samples.device)
sigmas = self.discrete_sigmas.to(original_samples.device)[timesteps]
noise = (
noise * sigmas[:, None, None, None]
if noise is not None
else torch.randn_like(original_samples) * sigmas[:, None, None, None]
)
noisy_samples = noise + original_samples
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_sde_ve.py |
# Copyright 2023 Zhejiang University Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils import SchedulerMixin, SchedulerOutput
class IPNDMScheduler(SchedulerMixin, ConfigMixin):
"""
A fourth-order Improved Pseudo Linear Multistep scheduler.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
"""
order = 1
@register_to_config
def __init__(
self, num_train_timesteps: int = 1000, trained_betas: Optional[Union[np.ndarray, List[float]]] = None
):
# set `betas`, `alphas`, `timesteps`
self.set_timesteps(num_train_timesteps)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# For now we only support F-PNDM, i.e. the runge-kutta method
# For more information on the algorithm please take a look at the paper: https://arxiv.org/pdf/2202.09778.pdf
# mainly at formula (9), (12), (13) and the Algorithm 2.
self.pndm_order = 4
# running values
self.ets = []
self._step_index = None
@property
def step_index(self):
"""
The index counter for current timestep. It will increae 1 after each scheduler step.
"""
return self._step_index
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
steps = torch.linspace(1, 0, num_inference_steps + 1)[:-1]
steps = torch.cat([steps, torch.tensor([0.0])])
if self.config.trained_betas is not None:
self.betas = torch.tensor(self.config.trained_betas, dtype=torch.float32)
else:
self.betas = torch.sin(steps * math.pi / 2) ** 2
self.alphas = (1.0 - self.betas**2) ** 0.5
timesteps = (torch.atan2(self.betas, self.alphas) / math.pi * 2)[:-1]
self.timesteps = timesteps.to(device)
self.ets = []
self._step_index = None
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._init_step_index
def _init_step_index(self, timestep):
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
index_candidates = (self.timesteps == timestep).nonzero()
# The sigma index that is taken for the **very** first `step`
# is always the second index (or the last index if there is only 1)
# This way we can ensure we don't accidentally skip a sigma in
# case we start in the middle of the denoising schedule (e.g. for image-to-image)
if len(index_candidates) > 1:
step_index = index_candidates[1]
else:
step_index = index_candidates[0]
self._step_index = step_index.item()
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the linear multistep method. It performs one forward pass multiple times to approximate the solution.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if self.step_index is None:
self._init_step_index(timestep)
timestep_index = self.step_index
prev_timestep_index = self.step_index + 1
ets = sample * self.betas[timestep_index] + model_output * self.alphas[timestep_index]
self.ets.append(ets)
if len(self.ets) == 1:
ets = self.ets[-1]
elif len(self.ets) == 2:
ets = (3 * self.ets[-1] - self.ets[-2]) / 2
elif len(self.ets) == 3:
ets = (23 * self.ets[-1] - 16 * self.ets[-2] + 5 * self.ets[-3]) / 12
else:
ets = (1 / 24) * (55 * self.ets[-1] - 59 * self.ets[-2] + 37 * self.ets[-3] - 9 * self.ets[-4])
prev_sample = self._get_prev_sample(sample, timestep_index, prev_timestep_index, ets)
# upon completion increase step index by one
self._step_index += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def scale_model_input(self, sample: torch.FloatTensor, *args, **kwargs) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def _get_prev_sample(self, sample, timestep_index, prev_timestep_index, ets):
alpha = self.alphas[timestep_index]
sigma = self.betas[timestep_index]
next_alpha = self.alphas[prev_timestep_index]
next_sigma = self.betas[prev_timestep_index]
pred = (sample - sigma * ets) / max(alpha, 1e-8)
prev_sample = next_alpha * pred + ets * next_sigma
return prev_sample
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_ipndm.py |
# Copyright 2023 FLAIR Lab and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: check https://arxiv.org/abs/2204.13902 and https://github.com/qsh-zh/deis for more info
# The codebase is modified based on https://github.com/huggingface/diffusers/blob/main/src/diffusers/schedulers/scheduling_dpmsolver_multistep.py
import math
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DEISMultistepScheduler(SchedulerMixin, ConfigMixin):
"""
`DEISMultistepScheduler` is a fast high order solver for diffusion ordinary differential equations (ODEs).
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
solver_order (`int`, defaults to 2):
The DEIS order which can be `1` or `2` or `3`. It is recommended to use `solver_order=2` for guided
sampling, and `solver_order=3` for unconditional sampling.
prediction_type (`str`, defaults to `epsilon`):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
thresholding (`bool`, defaults to `False`):
Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
as Stable Diffusion.
dynamic_thresholding_ratio (`float`, defaults to 0.995):
The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
sample_max_value (`float`, defaults to 1.0):
The threshold value for dynamic thresholding. Valid only when `thresholding=True`.
algorithm_type (`str`, defaults to `deis`):
The algorithm type for the solver.
lower_order_final (`bool`, defaults to `True`):
Whether to use lower-order solvers in the final steps. Only valid for < 15 inference steps.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[np.ndarray] = None,
solver_order: int = 2,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
sample_max_value: float = 1.0,
algorithm_type: str = "deis",
solver_type: str = "logrho",
lower_order_final: bool = True,
use_karras_sigmas: Optional[bool] = False,
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# Currently we only support VP-type noise schedule
self.alpha_t = torch.sqrt(self.alphas_cumprod)
self.sigma_t = torch.sqrt(1 - self.alphas_cumprod)
self.lambda_t = torch.log(self.alpha_t) - torch.log(self.sigma_t)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# settings for DEIS
if algorithm_type not in ["deis"]:
if algorithm_type in ["dpmsolver", "dpmsolver++"]:
self.register_to_config(algorithm_type="deis")
else:
raise NotImplementedError(f"{algorithm_type} does is not implemented for {self.__class__}")
if solver_type not in ["logrho"]:
if solver_type in ["midpoint", "heun", "bh1", "bh2"]:
self.register_to_config(solver_type="logrho")
else:
raise NotImplementedError(f"solver type {solver_type} does is not implemented for {self.__class__}")
# setable values
self.num_inference_steps = None
timesteps = np.linspace(0, num_train_timesteps - 1, num_train_timesteps, dtype=np.float32)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps)
self.model_outputs = [None] * solver_order
self.lower_order_nums = 0
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps + 1)
.round()[::-1][:-1]
.copy()
.astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // (num_inference_steps + 1)
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps + 1) * step_ratio).round()[::-1][:-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.arange(self.config.num_train_timesteps, 0, -step_ratio).round().copy().astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
if self.config.use_karras_sigmas:
log_sigmas = np.log(sigmas)
sigmas = self._convert_to_karras(in_sigmas=sigmas, num_inference_steps=num_inference_steps)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas]).round()
timesteps = np.flip(timesteps).copy().astype(np.int64)
self.sigmas = torch.from_numpy(sigmas)
# when num_inference_steps == num_train_timesteps, we can end up with
# duplicates in timesteps.
_, unique_indices = np.unique(timesteps, return_index=True)
timesteps = timesteps[np.sort(unique_indices)]
self.timesteps = torch.from_numpy(timesteps).to(device)
self.num_inference_steps = len(timesteps)
self.model_outputs = [
None,
] * self.config.solver_order
self.lower_order_nums = 0
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
def convert_model_output(
self, model_output: torch.FloatTensor, timestep: int, sample: torch.FloatTensor
) -> torch.FloatTensor:
"""
Convert the model output to the corresponding type the DEIS algorithm needs.
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The converted model output.
"""
if self.config.prediction_type == "epsilon":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = (sample - sigma_t * model_output) / alpha_t
elif self.config.prediction_type == "sample":
x0_pred = model_output
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = alpha_t * sample - sigma_t * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the DEISMultistepScheduler."
)
if self.config.thresholding:
x0_pred = self._threshold_sample(x0_pred)
if self.config.algorithm_type == "deis":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
return (sample - alpha_t * x0_pred) / sigma_t
else:
raise NotImplementedError("only support log-rho multistep deis now")
def deis_first_order_update(
self,
model_output: torch.FloatTensor,
timestep: int,
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the first-order DEIS (equivalent to DDIM).
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
lambda_t, lambda_s = self.lambda_t[prev_timestep], self.lambda_t[timestep]
alpha_t, alpha_s = self.alpha_t[prev_timestep], self.alpha_t[timestep]
sigma_t, _ = self.sigma_t[prev_timestep], self.sigma_t[timestep]
h = lambda_t - lambda_s
if self.config.algorithm_type == "deis":
x_t = (alpha_t / alpha_s) * sample - (sigma_t * (torch.exp(h) - 1.0)) * model_output
else:
raise NotImplementedError("only support log-rho multistep deis now")
return x_t
def multistep_deis_second_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the second-order multistep DEIS.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1 = prev_timestep, timestep_list[-1], timestep_list[-2]
m0, m1 = model_output_list[-1], model_output_list[-2]
alpha_t, alpha_s0, alpha_s1 = self.alpha_t[t], self.alpha_t[s0], self.alpha_t[s1]
sigma_t, sigma_s0, sigma_s1 = self.sigma_t[t], self.sigma_t[s0], self.sigma_t[s1]
rho_t, rho_s0, rho_s1 = sigma_t / alpha_t, sigma_s0 / alpha_s0, sigma_s1 / alpha_s1
if self.config.algorithm_type == "deis":
def ind_fn(t, b, c):
# Integrate[(log(t) - log(c)) / (log(b) - log(c)), {t}]
return t * (-np.log(c) + np.log(t) - 1) / (np.log(b) - np.log(c))
coef1 = ind_fn(rho_t, rho_s0, rho_s1) - ind_fn(rho_s0, rho_s0, rho_s1)
coef2 = ind_fn(rho_t, rho_s1, rho_s0) - ind_fn(rho_s0, rho_s1, rho_s0)
x_t = alpha_t * (sample / alpha_s0 + coef1 * m0 + coef2 * m1)
return x_t
else:
raise NotImplementedError("only support log-rho multistep deis now")
def multistep_deis_third_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the third-order multistep DEIS.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1, s2 = prev_timestep, timestep_list[-1], timestep_list[-2], timestep_list[-3]
m0, m1, m2 = model_output_list[-1], model_output_list[-2], model_output_list[-3]
alpha_t, alpha_s0, alpha_s1, alpha_s2 = self.alpha_t[t], self.alpha_t[s0], self.alpha_t[s1], self.alpha_t[s2]
sigma_t, sigma_s0, sigma_s1, simga_s2 = self.sigma_t[t], self.sigma_t[s0], self.sigma_t[s1], self.sigma_t[s2]
rho_t, rho_s0, rho_s1, rho_s2 = (
sigma_t / alpha_t,
sigma_s0 / alpha_s0,
sigma_s1 / alpha_s1,
simga_s2 / alpha_s2,
)
if self.config.algorithm_type == "deis":
def ind_fn(t, b, c, d):
# Integrate[(log(t) - log(c))(log(t) - log(d)) / (log(b) - log(c))(log(b) - log(d)), {t}]
numerator = t * (
np.log(c) * (np.log(d) - np.log(t) + 1)
- np.log(d) * np.log(t)
+ np.log(d)
+ np.log(t) ** 2
- 2 * np.log(t)
+ 2
)
denominator = (np.log(b) - np.log(c)) * (np.log(b) - np.log(d))
return numerator / denominator
coef1 = ind_fn(rho_t, rho_s0, rho_s1, rho_s2) - ind_fn(rho_s0, rho_s0, rho_s1, rho_s2)
coef2 = ind_fn(rho_t, rho_s1, rho_s2, rho_s0) - ind_fn(rho_s0, rho_s1, rho_s2, rho_s0)
coef3 = ind_fn(rho_t, rho_s2, rho_s0, rho_s1) - ind_fn(rho_s0, rho_s2, rho_s0, rho_s1)
x_t = alpha_t * (sample / alpha_s0 + coef1 * m0 + coef2 * m1 + coef3 * m2)
return x_t
else:
raise NotImplementedError("only support log-rho multistep deis now")
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the multistep DEIS.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
step_index = (self.timesteps == timestep).nonzero()
if len(step_index) == 0:
step_index = len(self.timesteps) - 1
else:
step_index = step_index.item()
prev_timestep = 0 if step_index == len(self.timesteps) - 1 else self.timesteps[step_index + 1]
lower_order_final = (
(step_index == len(self.timesteps) - 1) and self.config.lower_order_final and len(self.timesteps) < 15
)
lower_order_second = (
(step_index == len(self.timesteps) - 2) and self.config.lower_order_final and len(self.timesteps) < 15
)
model_output = self.convert_model_output(model_output, timestep, sample)
for i in range(self.config.solver_order - 1):
self.model_outputs[i] = self.model_outputs[i + 1]
self.model_outputs[-1] = model_output
if self.config.solver_order == 1 or self.lower_order_nums < 1 or lower_order_final:
prev_sample = self.deis_first_order_update(model_output, timestep, prev_timestep, sample)
elif self.config.solver_order == 2 or self.lower_order_nums < 2 or lower_order_second:
timestep_list = [self.timesteps[step_index - 1], timestep]
prev_sample = self.multistep_deis_second_order_update(
self.model_outputs, timestep_list, prev_timestep, sample
)
else:
timestep_list = [self.timesteps[step_index - 2], self.timesteps[step_index - 1], timestep]
prev_sample = self.multistep_deis_third_order_update(
self.model_outputs, timestep_list, prev_timestep, sample
)
if self.lower_order_nums < self.config.solver_order:
self.lower_order_nums += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def scale_model_input(self, sample: torch.FloatTensor, *args, **kwargs) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_deis_multistep.py |
# Copyright 2023 Kakao Brain and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import SchedulerMixin
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput with DDPM->UnCLIP
class UnCLIPSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class UnCLIPScheduler(SchedulerMixin, ConfigMixin):
"""
NOTE: do not use this scheduler. The DDPM scheduler has been updated to support the changes made here. This
scheduler will be removed and replaced with DDPM.
This is a modified DDPM Scheduler specifically for the karlo unCLIP model.
This scheduler has some minor variations in how it calculates the learned range variance and dynamically
re-calculates betas based off the timesteps it is skipping.
The scheduler also uses a slightly different step ratio when computing timesteps to use for inference.
See [`~DDPMScheduler`] for more information on DDPM scheduling
Args:
num_train_timesteps (`int`): number of diffusion steps used to train the model.
variance_type (`str`):
options to clip the variance used when adding noise to the denoised sample. Choose from `fixed_small_log`
or `learned_range`.
clip_sample (`bool`, default `True`):
option to clip predicted sample between `-clip_sample_range` and `clip_sample_range` for numerical
stability.
clip_sample_range (`float`, default `1.0`):
The range to clip the sample between. See `clip_sample`.
prediction_type (`str`, default `epsilon`, optional):
prediction type of the scheduler function, one of `epsilon` (predicting the noise of the diffusion process)
or `sample` (directly predicting the noisy sample`)
"""
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
variance_type: str = "fixed_small_log",
clip_sample: bool = True,
clip_sample_range: Optional[float] = 1.0,
prediction_type: str = "epsilon",
beta_schedule: str = "squaredcos_cap_v2",
):
if beta_schedule != "squaredcos_cap_v2":
raise ValueError("UnCLIPScheduler only supports `beta_schedule`: 'squaredcos_cap_v2'")
self.betas = betas_for_alpha_bar(num_train_timesteps)
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
self.one = torch.tensor(1.0)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# setable values
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy())
self.variance_type = variance_type
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`): input sample
timestep (`int`, optional): current timestep
Returns:
`torch.FloatTensor`: scaled input sample
"""
return sample
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference.
Note that this scheduler uses a slightly different step ratio than the other diffusers schedulers. The
different step ratio is to mimic the original karlo implementation and does not affect the quality or accuracy
of the results.
Args:
num_inference_steps (`int`):
the number of diffusion steps used when generating samples with a pre-trained model.
"""
self.num_inference_steps = num_inference_steps
step_ratio = (self.config.num_train_timesteps - 1) / (self.num_inference_steps - 1)
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.int64)
self.timesteps = torch.from_numpy(timesteps).to(device)
def _get_variance(self, t, prev_timestep=None, predicted_variance=None, variance_type=None):
if prev_timestep is None:
prev_timestep = t - 1
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.one
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
if prev_timestep == t - 1:
beta = self.betas[t]
else:
beta = 1 - alpha_prod_t / alpha_prod_t_prev
# For t > 0, compute predicted variance βt (see formula (6) and (7) from https://arxiv.org/pdf/2006.11239.pdf)
# and sample from it to get previous sample
# x_{t-1} ~ N(pred_prev_sample, variance) == add variance to pred_sample
variance = beta_prod_t_prev / beta_prod_t * beta
if variance_type is None:
variance_type = self.config.variance_type
# hacks - were probably added for training stability
if variance_type == "fixed_small_log":
variance = torch.log(torch.clamp(variance, min=1e-20))
variance = torch.exp(0.5 * variance)
elif variance_type == "learned_range":
# NOTE difference with DDPM scheduler
min_log = variance.log()
max_log = beta.log()
frac = (predicted_variance + 1) / 2
variance = frac * max_log + (1 - frac) * min_log
return variance
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
prev_timestep: Optional[int] = None,
generator=None,
return_dict: bool = True,
) -> Union[UnCLIPSchedulerOutput, Tuple]:
"""
Predict the sample at the previous timestep by reversing the SDE. Core function to propagate the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`): direct output from learned diffusion model.
timestep (`int`): current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
current instance of sample being created by diffusion process.
prev_timestep (`int`, *optional*): The previous timestep to predict the previous sample at.
Used to dynamically compute beta. If not given, `t-1` is used and the pre-computed beta is used.
generator: random number generator.
return_dict (`bool`): option for returning tuple rather than UnCLIPSchedulerOutput class
Returns:
[`~schedulers.scheduling_utils.UnCLIPSchedulerOutput`] or `tuple`:
[`~schedulers.scheduling_utils.UnCLIPSchedulerOutput`] if `return_dict` is True, otherwise a `tuple`. When
returning a tuple, the first element is the sample tensor.
"""
t = timestep
if model_output.shape[1] == sample.shape[1] * 2 and self.variance_type == "learned_range":
model_output, predicted_variance = torch.split(model_output, sample.shape[1], dim=1)
else:
predicted_variance = None
# 1. compute alphas, betas
if prev_timestep is None:
prev_timestep = t - 1
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.one
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
if prev_timestep == t - 1:
beta = self.betas[t]
alpha = self.alphas[t]
else:
beta = 1 - alpha_prod_t / alpha_prod_t_prev
alpha = 1 - beta
# 2. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon` or `sample`"
" for the UnCLIPScheduler."
)
# 3. Clip "predicted x_0"
if self.config.clip_sample:
pred_original_sample = torch.clamp(
pred_original_sample, -self.config.clip_sample_range, self.config.clip_sample_range
)
# 4. Compute coefficients for pred_original_sample x_0 and current sample x_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_original_sample_coeff = (alpha_prod_t_prev ** (0.5) * beta) / beta_prod_t
current_sample_coeff = alpha ** (0.5) * beta_prod_t_prev / beta_prod_t
# 5. Compute predicted previous sample µ_t
# See formula (7) from https://arxiv.org/pdf/2006.11239.pdf
pred_prev_sample = pred_original_sample_coeff * pred_original_sample + current_sample_coeff * sample
# 6. Add noise
variance = 0
if t > 0:
variance_noise = randn_tensor(
model_output.shape, dtype=model_output.dtype, generator=generator, device=model_output.device
)
variance = self._get_variance(
t,
predicted_variance=predicted_variance,
prev_timestep=prev_timestep,
)
if self.variance_type == "fixed_small_log":
variance = variance
elif self.variance_type == "learned_range":
variance = (0.5 * variance).exp()
else:
raise ValueError(
f"variance_type given as {self.variance_type} must be one of `fixed_small_log` or `learned_range`"
" for the UnCLIPScheduler."
)
variance = variance * variance_noise
pred_prev_sample = pred_prev_sample + variance
if not return_dict:
return (pred_prev_sample,)
return UnCLIPSchedulerOutput(prev_sample=pred_prev_sample, pred_original_sample=pred_original_sample)
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
| diffusers-main | src/diffusers/schedulers/scheduling_unclip.py |
# Copyright 2023 Microsoft and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import numpy as np
import torch
import torch.nn.functional as F
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from .scheduling_utils import SchedulerMixin
@dataclass
class VQDiffusionSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's step function output.
Args:
prev_sample (`torch.LongTensor` of shape `(batch size, num latent pixels)`):
Computed sample x_{t-1} of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
"""
prev_sample: torch.LongTensor
def index_to_log_onehot(x: torch.LongTensor, num_classes: int) -> torch.FloatTensor:
"""
Convert batch of vector of class indices into batch of log onehot vectors
Args:
x (`torch.LongTensor` of shape `(batch size, vector length)`):
Batch of class indices
num_classes (`int`):
number of classes to be used for the onehot vectors
Returns:
`torch.FloatTensor` of shape `(batch size, num classes, vector length)`:
Log onehot vectors
"""
x_onehot = F.one_hot(x, num_classes)
x_onehot = x_onehot.permute(0, 2, 1)
log_x = torch.log(x_onehot.float().clamp(min=1e-30))
return log_x
def gumbel_noised(logits: torch.FloatTensor, generator: Optional[torch.Generator]) -> torch.FloatTensor:
"""
Apply gumbel noise to `logits`
"""
uniform = torch.rand(logits.shape, device=logits.device, generator=generator)
gumbel_noise = -torch.log(-torch.log(uniform + 1e-30) + 1e-30)
noised = gumbel_noise + logits
return noised
def alpha_schedules(num_diffusion_timesteps: int, alpha_cum_start=0.99999, alpha_cum_end=0.000009):
"""
Cumulative and non-cumulative alpha schedules.
See section 4.1.
"""
att = (
np.arange(0, num_diffusion_timesteps) / (num_diffusion_timesteps - 1) * (alpha_cum_end - alpha_cum_start)
+ alpha_cum_start
)
att = np.concatenate(([1], att))
at = att[1:] / att[:-1]
att = np.concatenate((att[1:], [1]))
return at, att
def gamma_schedules(num_diffusion_timesteps: int, gamma_cum_start=0.000009, gamma_cum_end=0.99999):
"""
Cumulative and non-cumulative gamma schedules.
See section 4.1.
"""
ctt = (
np.arange(0, num_diffusion_timesteps) / (num_diffusion_timesteps - 1) * (gamma_cum_end - gamma_cum_start)
+ gamma_cum_start
)
ctt = np.concatenate(([0], ctt))
one_minus_ctt = 1 - ctt
one_minus_ct = one_minus_ctt[1:] / one_minus_ctt[:-1]
ct = 1 - one_minus_ct
ctt = np.concatenate((ctt[1:], [0]))
return ct, ctt
class VQDiffusionScheduler(SchedulerMixin, ConfigMixin):
"""
A scheduler for vector quantized diffusion.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_vec_classes (`int`):
The number of classes of the vector embeddings of the latent pixels. Includes the class for the masked
latent pixel.
num_train_timesteps (`int`, defaults to 100):
The number of diffusion steps to train the model.
alpha_cum_start (`float`, defaults to 0.99999):
The starting cumulative alpha value.
alpha_cum_end (`float`, defaults to 0.00009):
The ending cumulative alpha value.
gamma_cum_start (`float`, defaults to 0.00009):
The starting cumulative gamma value.
gamma_cum_end (`float`, defaults to 0.99999):
The ending cumulative gamma value.
"""
order = 1
@register_to_config
def __init__(
self,
num_vec_classes: int,
num_train_timesteps: int = 100,
alpha_cum_start: float = 0.99999,
alpha_cum_end: float = 0.000009,
gamma_cum_start: float = 0.000009,
gamma_cum_end: float = 0.99999,
):
self.num_embed = num_vec_classes
# By convention, the index for the mask class is the last class index
self.mask_class = self.num_embed - 1
at, att = alpha_schedules(num_train_timesteps, alpha_cum_start=alpha_cum_start, alpha_cum_end=alpha_cum_end)
ct, ctt = gamma_schedules(num_train_timesteps, gamma_cum_start=gamma_cum_start, gamma_cum_end=gamma_cum_end)
num_non_mask_classes = self.num_embed - 1
bt = (1 - at - ct) / num_non_mask_classes
btt = (1 - att - ctt) / num_non_mask_classes
at = torch.tensor(at.astype("float64"))
bt = torch.tensor(bt.astype("float64"))
ct = torch.tensor(ct.astype("float64"))
log_at = torch.log(at)
log_bt = torch.log(bt)
log_ct = torch.log(ct)
att = torch.tensor(att.astype("float64"))
btt = torch.tensor(btt.astype("float64"))
ctt = torch.tensor(ctt.astype("float64"))
log_cumprod_at = torch.log(att)
log_cumprod_bt = torch.log(btt)
log_cumprod_ct = torch.log(ctt)
self.log_at = log_at.float()
self.log_bt = log_bt.float()
self.log_ct = log_ct.float()
self.log_cumprod_at = log_cumprod_at.float()
self.log_cumprod_bt = log_cumprod_bt.float()
self.log_cumprod_ct = log_cumprod_ct.float()
# setable values
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy())
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps and diffusion process parameters (alpha, beta, gamma) should be moved
to.
"""
self.num_inference_steps = num_inference_steps
timesteps = np.arange(0, self.num_inference_steps)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps).to(device)
self.log_at = self.log_at.to(device)
self.log_bt = self.log_bt.to(device)
self.log_ct = self.log_ct.to(device)
self.log_cumprod_at = self.log_cumprod_at.to(device)
self.log_cumprod_bt = self.log_cumprod_bt.to(device)
self.log_cumprod_ct = self.log_cumprod_ct.to(device)
def step(
self,
model_output: torch.FloatTensor,
timestep: torch.long,
sample: torch.LongTensor,
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[VQDiffusionSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by the reverse transition distribution. See
[`~VQDiffusionScheduler.q_posterior`] for more details about how the distribution is computer.
Args:
log_p_x_0: (`torch.FloatTensor` of shape `(batch size, num classes - 1, num latent pixels)`):
The log probabilities for the predicted classes of the initial latent pixels. Does not include a
prediction for the masked class as the initial unnoised image cannot be masked.
t (`torch.long`):
The timestep that determines which transition matrices are used.
x_t (`torch.LongTensor` of shape `(batch size, num latent pixels)`):
The classes of each latent pixel at time `t`.
generator (`torch.Generator`, or `None`):
A random number generator for the noise applied to `p(x_{t-1} | x_t)` before it is sampled from.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_vq_diffusion.VQDiffusionSchedulerOutput`] or
`tuple`.
Returns:
[`~schedulers.scheduling_vq_diffusion.VQDiffusionSchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_vq_diffusion.VQDiffusionSchedulerOutput`] is
returned, otherwise a tuple is returned where the first element is the sample tensor.
"""
if timestep == 0:
log_p_x_t_min_1 = model_output
else:
log_p_x_t_min_1 = self.q_posterior(model_output, sample, timestep)
log_p_x_t_min_1 = gumbel_noised(log_p_x_t_min_1, generator)
x_t_min_1 = log_p_x_t_min_1.argmax(dim=1)
if not return_dict:
return (x_t_min_1,)
return VQDiffusionSchedulerOutput(prev_sample=x_t_min_1)
def q_posterior(self, log_p_x_0, x_t, t):
"""
Calculates the log probabilities for the predicted classes of the image at timestep `t-1`:
```
p(x_{t-1} | x_t) = sum( q(x_t | x_{t-1}) * q(x_{t-1} | x_0) * p(x_0) / q(x_t | x_0) )
```
Args:
log_p_x_0 (`torch.FloatTensor` of shape `(batch size, num classes - 1, num latent pixels)`):
The log probabilities for the predicted classes of the initial latent pixels. Does not include a
prediction for the masked class as the initial unnoised image cannot be masked.
x_t (`torch.LongTensor` of shape `(batch size, num latent pixels)`):
The classes of each latent pixel at time `t`.
t (`torch.Long`):
The timestep that determines which transition matrix is used.
Returns:
`torch.FloatTensor` of shape `(batch size, num classes, num latent pixels)`:
The log probabilities for the predicted classes of the image at timestep `t-1`.
"""
log_onehot_x_t = index_to_log_onehot(x_t, self.num_embed)
log_q_x_t_given_x_0 = self.log_Q_t_transitioning_to_known_class(
t=t, x_t=x_t, log_onehot_x_t=log_onehot_x_t, cumulative=True
)
log_q_t_given_x_t_min_1 = self.log_Q_t_transitioning_to_known_class(
t=t, x_t=x_t, log_onehot_x_t=log_onehot_x_t, cumulative=False
)
# p_0(x_0=C_0 | x_t) / q(x_t | x_0=C_0) ... p_n(x_0=C_0 | x_t) / q(x_t | x_0=C_0)
# . . .
# . . .
# . . .
# p_0(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}) ... p_n(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1})
q = log_p_x_0 - log_q_x_t_given_x_0
# sum_0 = p_0(x_0=C_0 | x_t) / q(x_t | x_0=C_0) + ... + p_0(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}), ... ,
# sum_n = p_n(x_0=C_0 | x_t) / q(x_t | x_0=C_0) + ... + p_n(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1})
q_log_sum_exp = torch.logsumexp(q, dim=1, keepdim=True)
# p_0(x_0=C_0 | x_t) / q(x_t | x_0=C_0) / sum_0 ... p_n(x_0=C_0 | x_t) / q(x_t | x_0=C_0) / sum_n
# . . .
# . . .
# . . .
# p_0(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}) / sum_0 ... p_n(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}) / sum_n
q = q - q_log_sum_exp
# (p_0(x_0=C_0 | x_t) / q(x_t | x_0=C_0) / sum_0) * a_cumulative_{t-1} + b_cumulative_{t-1} ... (p_n(x_0=C_0 | x_t) / q(x_t | x_0=C_0) / sum_n) * a_cumulative_{t-1} + b_cumulative_{t-1}
# . . .
# . . .
# . . .
# (p_0(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}) / sum_0) * a_cumulative_{t-1} + b_cumulative_{t-1} ... (p_n(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}) / sum_n) * a_cumulative_{t-1} + b_cumulative_{t-1}
# c_cumulative_{t-1} ... c_cumulative_{t-1}
q = self.apply_cumulative_transitions(q, t - 1)
# ((p_0(x_0=C_0 | x_t) / q(x_t | x_0=C_0) / sum_0) * a_cumulative_{t-1} + b_cumulative_{t-1}) * q(x_t | x_{t-1}=C_0) * sum_0 ... ((p_n(x_0=C_0 | x_t) / q(x_t | x_0=C_0) / sum_n) * a_cumulative_{t-1} + b_cumulative_{t-1}) * q(x_t | x_{t-1}=C_0) * sum_n
# . . .
# . . .
# . . .
# ((p_0(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}) / sum_0) * a_cumulative_{t-1} + b_cumulative_{t-1}) * q(x_t | x_{t-1}=C_{k-1}) * sum_0 ... ((p_n(x_0=C_{k-1} | x_t) / q(x_t | x_0=C_{k-1}) / sum_n) * a_cumulative_{t-1} + b_cumulative_{t-1}) * q(x_t | x_{t-1}=C_{k-1}) * sum_n
# c_cumulative_{t-1} * q(x_t | x_{t-1}=C_k) * sum_0 ... c_cumulative_{t-1} * q(x_t | x_{t-1}=C_k) * sum_0
log_p_x_t_min_1 = q + log_q_t_given_x_t_min_1 + q_log_sum_exp
# For each column, there are two possible cases.
#
# Where:
# - sum(p_n(x_0))) is summing over all classes for x_0
# - C_i is the class transitioning from (not to be confused with c_t and c_cumulative_t being used for gamma's)
# - C_j is the class transitioning to
#
# 1. x_t is masked i.e. x_t = c_k
#
# Simplifying the expression, the column vector is:
# .
# .
# .
# (c_t / c_cumulative_t) * (a_cumulative_{t-1} * p_n(x_0 = C_i | x_t) + b_cumulative_{t-1} * sum(p_n(x_0)))
# .
# .
# .
# (c_cumulative_{t-1} / c_cumulative_t) * sum(p_n(x_0))
#
# From equation (11) stated in terms of forward probabilities, the last row is trivially verified.
#
# For the other rows, we can state the equation as ...
#
# (c_t / c_cumulative_t) * [b_cumulative_{t-1} * p(x_0=c_0) + ... + (a_cumulative_{t-1} + b_cumulative_{t-1}) * p(x_0=C_i) + ... + b_cumulative_{k-1} * p(x_0=c_{k-1})]
#
# This verifies the other rows.
#
# 2. x_t is not masked
#
# Simplifying the expression, there are two cases for the rows of the column vector, where C_j = C_i and where C_j != C_i:
# .
# .
# .
# C_j != C_i: b_t * ((b_cumulative_{t-1} / b_cumulative_t) * p_n(x_0 = c_0) + ... + ((a_cumulative_{t-1} + b_cumulative_{t-1}) / b_cumulative_t) * p_n(x_0 = C_i) + ... + (b_cumulative_{t-1} / (a_cumulative_t + b_cumulative_t)) * p_n(c_0=C_j) + ... + (b_cumulative_{t-1} / b_cumulative_t) * p_n(x_0 = c_{k-1}))
# .
# .
# .
# C_j = C_i: (a_t + b_t) * ((b_cumulative_{t-1} / b_cumulative_t) * p_n(x_0 = c_0) + ... + ((a_cumulative_{t-1} + b_cumulative_{t-1}) / (a_cumulative_t + b_cumulative_t)) * p_n(x_0 = C_i = C_j) + ... + (b_cumulative_{t-1} / b_cumulative_t) * p_n(x_0 = c_{k-1}))
# .
# .
# .
# 0
#
# The last row is trivially verified. The other rows can be verified by directly expanding equation (11) stated in terms of forward probabilities.
return log_p_x_t_min_1
def log_Q_t_transitioning_to_known_class(
self, *, t: torch.int, x_t: torch.LongTensor, log_onehot_x_t: torch.FloatTensor, cumulative: bool
):
"""
Calculates the log probabilities of the rows from the (cumulative or non-cumulative) transition matrix for each
latent pixel in `x_t`.
Args:
t (`torch.Long`):
The timestep that determines which transition matrix is used.
x_t (`torch.LongTensor` of shape `(batch size, num latent pixels)`):
The classes of each latent pixel at time `t`.
log_onehot_x_t (`torch.FloatTensor` of shape `(batch size, num classes, num latent pixels)`):
The log one-hot vectors of `x_t`.
cumulative (`bool`):
If cumulative is `False`, the single step transition matrix `t-1`->`t` is used. If cumulative is
`True`, the cumulative transition matrix `0`->`t` is used.
Returns:
`torch.FloatTensor` of shape `(batch size, num classes - 1, num latent pixels)`:
Each _column_ of the returned matrix is a _row_ of log probabilities of the complete probability
transition matrix.
When non cumulative, returns `self.num_classes - 1` rows because the initial latent pixel cannot be
masked.
Where:
- `q_n` is the probability distribution for the forward process of the `n`th latent pixel.
- C_0 is a class of a latent pixel embedding
- C_k is the class of the masked latent pixel
non-cumulative result (omitting logarithms):
```
q_0(x_t | x_{t-1} = C_0) ... q_n(x_t | x_{t-1} = C_0)
. . .
. . .
. . .
q_0(x_t | x_{t-1} = C_k) ... q_n(x_t | x_{t-1} = C_k)
```
cumulative result (omitting logarithms):
```
q_0_cumulative(x_t | x_0 = C_0) ... q_n_cumulative(x_t | x_0 = C_0)
. . .
. . .
. . .
q_0_cumulative(x_t | x_0 = C_{k-1}) ... q_n_cumulative(x_t | x_0 = C_{k-1})
```
"""
if cumulative:
a = self.log_cumprod_at[t]
b = self.log_cumprod_bt[t]
c = self.log_cumprod_ct[t]
else:
a = self.log_at[t]
b = self.log_bt[t]
c = self.log_ct[t]
if not cumulative:
# The values in the onehot vector can also be used as the logprobs for transitioning
# from masked latent pixels. If we are not calculating the cumulative transitions,
# we need to save these vectors to be re-appended to the final matrix so the values
# aren't overwritten.
#
# `P(x_t!=mask|x_{t-1=mask}) = 0` and 0 will be the value of the last row of the onehot vector
# if x_t is not masked
#
# `P(x_t=mask|x_{t-1=mask}) = 1` and 1 will be the value of the last row of the onehot vector
# if x_t is masked
log_onehot_x_t_transitioning_from_masked = log_onehot_x_t[:, -1, :].unsqueeze(1)
# `index_to_log_onehot` will add onehot vectors for masked pixels,
# so the default one hot matrix has one too many rows. See the doc string
# for an explanation of the dimensionality of the returned matrix.
log_onehot_x_t = log_onehot_x_t[:, :-1, :]
# this is a cheeky trick to produce the transition probabilities using log one-hot vectors.
#
# Don't worry about what values this sets in the columns that mark transitions
# to masked latent pixels. They are overwrote later with the `mask_class_mask`.
#
# Looking at the below logspace formula in non-logspace, each value will evaluate to either
# `1 * a + b = a + b` where `log_Q_t` has the one hot value in the column
# or
# `0 * a + b = b` where `log_Q_t` has the 0 values in the column.
#
# See equation 7 for more details.
log_Q_t = (log_onehot_x_t + a).logaddexp(b)
# The whole column of each masked pixel is `c`
mask_class_mask = x_t == self.mask_class
mask_class_mask = mask_class_mask.unsqueeze(1).expand(-1, self.num_embed - 1, -1)
log_Q_t[mask_class_mask] = c
if not cumulative:
log_Q_t = torch.cat((log_Q_t, log_onehot_x_t_transitioning_from_masked), dim=1)
return log_Q_t
def apply_cumulative_transitions(self, q, t):
bsz = q.shape[0]
a = self.log_cumprod_at[t]
b = self.log_cumprod_bt[t]
c = self.log_cumprod_ct[t]
num_latent_pixels = q.shape[2]
c = c.expand(bsz, 1, num_latent_pixels)
q = (q + a).logaddexp(b)
q = torch.cat((q, c), dim=1)
return q
| diffusers-main | src/diffusers/schedulers/scheduling_vq_diffusion.py |
# Copyright 2023 ETH Zurich Computer Vision Lab and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from dataclasses import dataclass
from typing import Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import SchedulerMixin
@dataclass
class RePaintSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's step function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample (x_{0}) based on the model output from
the current timestep. `pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: torch.FloatTensor
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class RePaintScheduler(SchedulerMixin, ConfigMixin):
"""
`RePaintScheduler` is a scheduler for DDPM inpainting inside a given mask.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, `squaredcos_cap_v2`, or `sigmoid`.
eta (`float`):
The weight of noise for added noise in diffusion step. If its value is between 0.0 and 1.0 it corresponds
to the DDIM scheduler, and if its value is between -0.0 and 1.0 it corresponds to the DDPM scheduler.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
clip_sample (`bool`, defaults to `True`):
Clip the predicted sample between -1 and 1 for numerical stability.
"""
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
eta: float = 0.0,
trained_betas: Optional[np.ndarray] = None,
clip_sample: bool = True,
):
if trained_betas is not None:
self.betas = torch.from_numpy(trained_betas)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
elif beta_schedule == "sigmoid":
# GeoDiff sigmoid schedule
betas = torch.linspace(-6, 6, num_train_timesteps)
self.betas = torch.sigmoid(betas) * (beta_end - beta_start) + beta_start
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
self.one = torch.tensor(1.0)
self.final_alpha_cumprod = torch.tensor(1.0)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# setable values
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy())
self.eta = eta
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def set_timesteps(
self,
num_inference_steps: int,
jump_length: int = 10,
jump_n_sample: int = 10,
device: Union[str, torch.device] = None,
):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model. If used,
`timesteps` must be `None`.
jump_length (`int`, defaults to 10):
The number of steps taken forward in time before going backward in time for a single jump (“j” in
RePaint paper). Take a look at Figure 9 and 10 in the paper.
jump_n_sample (`int`, defaults to 10):
The number of times to make a forward time jump for a given chosen time sample. Take a look at Figure 9
and 10 in the paper.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
num_inference_steps = min(self.config.num_train_timesteps, num_inference_steps)
self.num_inference_steps = num_inference_steps
timesteps = []
jumps = {}
for j in range(0, num_inference_steps - jump_length, jump_length):
jumps[j] = jump_n_sample - 1
t = num_inference_steps
while t >= 1:
t = t - 1
timesteps.append(t)
if jumps.get(t, 0) > 0:
jumps[t] = jumps[t] - 1
for _ in range(jump_length):
t = t + 1
timesteps.append(t)
timesteps = np.array(timesteps) * (self.config.num_train_timesteps // self.num_inference_steps)
self.timesteps = torch.from_numpy(timesteps).to(device)
def _get_variance(self, t):
prev_timestep = t - self.config.num_train_timesteps // self.num_inference_steps
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.final_alpha_cumprod
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
# For t > 0, compute predicted variance βt (see formula (6) and (7) from
# https://arxiv.org/pdf/2006.11239.pdf) and sample from it to get
# previous sample x_{t-1} ~ N(pred_prev_sample, variance) == add
# variance to pred_sample
# Is equivalent to formula (16) in https://arxiv.org/pdf/2010.02502.pdf
# without eta.
# variance = (1 - alpha_prod_t_prev) / (1 - alpha_prod_t) * self.betas[t]
variance = (beta_prod_t_prev / beta_prod_t) * (1 - alpha_prod_t / alpha_prod_t_prev)
return variance
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
original_image: torch.FloatTensor,
mask: torch.FloatTensor,
generator: Optional[torch.Generator] = None,
return_dict: bool = True,
) -> Union[RePaintSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
original_image (`torch.FloatTensor`):
The original image to inpaint on.
mask (`torch.FloatTensor`):
The mask where a value of 0.0 indicates which part of the original image to inpaint.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_repaint.RePaintSchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_repaint.RePaintSchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_repaint.RePaintSchedulerOutput`] is returned,
otherwise a tuple is returned where the first element is the sample tensor.
"""
t = timestep
prev_timestep = timestep - self.config.num_train_timesteps // self.num_inference_steps
# 1. compute alphas, betas
alpha_prod_t = self.alphas_cumprod[t]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.final_alpha_cumprod
beta_prod_t = 1 - alpha_prod_t
# 2. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
pred_original_sample = (sample - beta_prod_t**0.5 * model_output) / alpha_prod_t**0.5
# 3. Clip "predicted x_0"
if self.config.clip_sample:
pred_original_sample = torch.clamp(pred_original_sample, -1, 1)
# We choose to follow RePaint Algorithm 1 to get x_{t-1}, however we
# substitute formula (7) in the algorithm coming from DDPM paper
# (formula (4) Algorithm 2 - Sampling) with formula (12) from DDIM paper.
# DDIM schedule gives the same results as DDPM with eta = 1.0
# Noise is being reused in 7. and 8., but no impact on quality has
# been observed.
# 5. Add noise
device = model_output.device
noise = randn_tensor(model_output.shape, generator=generator, device=device, dtype=model_output.dtype)
std_dev_t = self.eta * self._get_variance(timestep) ** 0.5
variance = 0
if t > 0 and self.eta > 0:
variance = std_dev_t * noise
# 6. compute "direction pointing to x_t" of formula (12)
# from https://arxiv.org/pdf/2010.02502.pdf
pred_sample_direction = (1 - alpha_prod_t_prev - std_dev_t**2) ** 0.5 * model_output
# 7. compute x_{t-1} of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
prev_unknown_part = alpha_prod_t_prev**0.5 * pred_original_sample + pred_sample_direction + variance
# 8. Algorithm 1 Line 5 https://arxiv.org/pdf/2201.09865.pdf
prev_known_part = (alpha_prod_t_prev**0.5) * original_image + ((1 - alpha_prod_t_prev) ** 0.5) * noise
# 9. Algorithm 1 Line 8 https://arxiv.org/pdf/2201.09865.pdf
pred_prev_sample = mask * prev_known_part + (1.0 - mask) * prev_unknown_part
if not return_dict:
return (
pred_prev_sample,
pred_original_sample,
)
return RePaintSchedulerOutput(prev_sample=pred_prev_sample, pred_original_sample=pred_original_sample)
def undo_step(self, sample, timestep, generator=None):
n = self.config.num_train_timesteps // self.num_inference_steps
for i in range(n):
beta = self.betas[timestep + i]
if sample.device.type == "mps":
# randn does not work reproducibly on mps
noise = randn_tensor(sample.shape, dtype=sample.dtype, generator=generator)
noise = noise.to(sample.device)
else:
noise = randn_tensor(sample.shape, generator=generator, device=sample.device, dtype=sample.dtype)
# 10. Algorithm 1 Line 10 https://arxiv.org/pdf/2201.09865.pdf
sample = (1 - beta) ** 0.5 * sample + beta**0.5 * noise
return sample
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
raise NotImplementedError("Use `DDPMScheduler.add_noise()` to train for sampling with RePaint.")
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_repaint.py |
# Copyright 2023 Stanford University Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This code is strongly influenced by https://github.com/pesser/pytorch_diffusion
# and https://github.com/hojonathanho/diffusion
import math
from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils import BaseOutput
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
@dataclass
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput with DDPM->DDIM
class DDIMSchedulerOutput(BaseOutput):
"""
Output class for the scheduler's `step` function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
`pred_original_sample` can be used to preview progress or for guidance.
"""
prev_sample: torch.FloatTensor
pred_original_sample: Optional[torch.FloatTensor] = None
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
def rescale_zero_terminal_snr(betas):
"""
Rescales betas to have zero terminal SNR Based on https://arxiv.org/pdf/2305.08891.pdf (Algorithm 1)
Args:
betas (`torch.FloatTensor`):
the betas that the scheduler is being initialized with.
Returns:
`torch.FloatTensor`: rescaled betas with zero terminal SNR
"""
# Convert betas to alphas_bar_sqrt
alphas = 1.0 - betas
alphas_cumprod = torch.cumprod(alphas, dim=0)
alphas_bar_sqrt = alphas_cumprod.sqrt()
# Store old values.
alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
# Shift so the last timestep is zero.
alphas_bar_sqrt -= alphas_bar_sqrt_T
# Scale so the first timestep is back to the old value.
alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
# Convert alphas_bar_sqrt to betas
alphas_bar = alphas_bar_sqrt**2 # Revert sqrt
alphas = alphas_bar[1:] / alphas_bar[:-1] # Revert cumprod
alphas = torch.cat([alphas_bar[0:1], alphas])
betas = 1 - alphas
return betas
class DDIMScheduler(SchedulerMixin, ConfigMixin):
"""
`DDIMScheduler` extends the denoising procedure introduced in denoising diffusion probabilistic models (DDPMs) with
non-Markovian guidance.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
clip_sample (`bool`, defaults to `True`):
Clip the predicted sample for numerical stability.
clip_sample_range (`float`, defaults to 1.0):
The maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
set_alpha_to_one (`bool`, defaults to `True`):
Each diffusion step uses the alphas product value at that step and at the previous one. For the final step
there is no previous alpha. When this option is `True` the previous alpha product is fixed to `1`,
otherwise it uses the alpha value at step 0.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
thresholding (`bool`, defaults to `False`):
Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
as Stable Diffusion.
dynamic_thresholding_ratio (`float`, defaults to 0.995):
The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
sample_max_value (`float`, defaults to 1.0):
The threshold value for dynamic thresholding. Valid only when `thresholding=True`.
timestep_spacing (`str`, defaults to `"leading"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
rescale_betas_zero_snr (`bool`, defaults to `False`):
Whether to rescale the betas to have zero terminal SNR. This enables the model to generate very bright and
dark samples instead of limiting it to samples with medium brightness. Loosely related to
[`--offset_noise`](https://github.com/huggingface/diffusers/blob/74fd735eb073eb1d774b1ab4154a0876eb82f055/examples/dreambooth/train_dreambooth.py#L506).
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
clip_sample: bool = True,
set_alpha_to_one: bool = True,
steps_offset: int = 0,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
clip_sample_range: float = 1.0,
sample_max_value: float = 1.0,
timestep_spacing: str = "leading",
rescale_betas_zero_snr: bool = False,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
# Rescale for zero SNR
if rescale_betas_zero_snr:
self.betas = rescale_zero_terminal_snr(self.betas)
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# At every step in ddim, we are looking into the previous alphas_cumprod
# For the final step, there is no previous alphas_cumprod because we are already at 0
# `set_alpha_to_one` decides whether we set this parameter simply to one or
# whether we use the final alpha of the "non-previous" one.
self.final_alpha_cumprod = torch.tensor(1.0) if set_alpha_to_one else self.alphas_cumprod[0]
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# setable values
self.num_inference_steps = None
self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy().astype(np.int64))
def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
timestep (`int`, *optional*):
The current timestep in the diffusion chain.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def _get_variance(self, timestep, prev_timestep):
alpha_prod_t = self.alphas_cumprod[timestep]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.final_alpha_cumprod
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
variance = (beta_prod_t_prev / beta_prod_t) * (1 - alpha_prod_t / alpha_prod_t_prev)
return variance
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
"""
if num_inference_steps > self.config.num_train_timesteps:
raise ValueError(
f"`num_inference_steps`: {num_inference_steps} cannot be larger than `self.config.train_timesteps`:"
f" {self.config.num_train_timesteps} as the unet model trained with this scheduler can only handle"
f" maximal {self.config.num_train_timesteps} timesteps."
)
self.num_inference_steps = num_inference_steps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps)
.round()[::-1]
.copy()
.astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.round(np.arange(self.config.num_train_timesteps, 0, -step_ratio)).astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'leading' or 'trailing'."
)
self.timesteps = torch.from_numpy(timesteps).to(device)
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
eta: float = 0.0,
use_clipped_model_output: bool = False,
generator=None,
variance_noise: Optional[torch.FloatTensor] = None,
return_dict: bool = True,
) -> Union[DDIMSchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise).
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`float`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
eta (`float`):
The weight of noise for added noise in diffusion step.
use_clipped_model_output (`bool`, defaults to `False`):
If `True`, computes "corrected" `model_output` from the clipped predicted original sample. Necessary
because predicted original sample is clipped to [-1, 1] when `self.config.clip_sample` is `True`. If no
clipping has happened, "corrected" `model_output` would coincide with the one provided as input and
`use_clipped_model_output` has no effect.
generator (`torch.Generator`, *optional*):
A random number generator.
variance_noise (`torch.FloatTensor`):
Alternative to generating noise with `generator` by directly providing the noise for the variance
itself. Useful for methods such as [`CycleDiffusion`].
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~schedulers.scheduling_ddim.DDIMSchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_utils.DDIMSchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_ddim.DDIMSchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
# See formulas (12) and (16) of DDIM paper https://arxiv.org/pdf/2010.02502.pdf
# Ideally, read DDIM paper in-detail understanding
# Notation (<variable name> -> <name in paper>
# - pred_noise_t -> e_theta(x_t, t)
# - pred_original_sample -> f_theta(x_t, t) or x_0
# - std_dev_t -> sigma_t
# - eta -> η
# - pred_sample_direction -> "direction pointing to x_t"
# - pred_prev_sample -> "x_t-1"
# 1. get previous step value (=t-1)
prev_timestep = timestep - self.config.num_train_timesteps // self.num_inference_steps
# 2. compute alphas, betas
alpha_prod_t = self.alphas_cumprod[timestep]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.final_alpha_cumprod
beta_prod_t = 1 - alpha_prod_t
# 3. compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
if self.config.prediction_type == "epsilon":
pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
pred_epsilon = model_output
elif self.config.prediction_type == "sample":
pred_original_sample = model_output
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
elif self.config.prediction_type == "v_prediction":
pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
pred_epsilon = (alpha_prod_t**0.5) * model_output + (beta_prod_t**0.5) * sample
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction`"
)
# 4. Clip or threshold "predicted x_0"
if self.config.thresholding:
pred_original_sample = self._threshold_sample(pred_original_sample)
elif self.config.clip_sample:
pred_original_sample = pred_original_sample.clamp(
-self.config.clip_sample_range, self.config.clip_sample_range
)
# 5. compute variance: "sigma_t(η)" -> see formula (16)
# σ_t = sqrt((1 − α_t−1)/(1 − α_t)) * sqrt(1 − α_t/α_t−1)
variance = self._get_variance(timestep, prev_timestep)
std_dev_t = eta * variance ** (0.5)
if use_clipped_model_output:
# the pred_epsilon is always re-derived from the clipped x_0 in Glide
pred_epsilon = (sample - alpha_prod_t ** (0.5) * pred_original_sample) / beta_prod_t ** (0.5)
# 6. compute "direction pointing to x_t" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
pred_sample_direction = (1 - alpha_prod_t_prev - std_dev_t**2) ** (0.5) * pred_epsilon
# 7. compute x_t without "random noise" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
prev_sample = alpha_prod_t_prev ** (0.5) * pred_original_sample + pred_sample_direction
if eta > 0:
if variance_noise is not None and generator is not None:
raise ValueError(
"Cannot pass both generator and variance_noise. Please make sure that either `generator` or"
" `variance_noise` stays `None`."
)
if variance_noise is None:
variance_noise = randn_tensor(
model_output.shape, generator=generator, device=model_output.device, dtype=model_output.dtype
)
variance = std_dev_t * variance_noise
prev_sample = prev_sample + variance
if not return_dict:
return (prev_sample,)
return DDIMSchedulerOutput(prev_sample=prev_sample, pred_original_sample=pred_original_sample)
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.get_velocity
def get_velocity(
self, sample: torch.FloatTensor, noise: torch.FloatTensor, timesteps: torch.IntTensor
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as sample
alphas_cumprod = self.alphas_cumprod.to(device=sample.device, dtype=sample.dtype)
timesteps = timesteps.to(sample.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(sample.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(sample.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
velocity = sqrt_alpha_prod * noise - sqrt_one_minus_alpha_prod * sample
return velocity
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_ddim.py |
# Copyright 2023 Zhejiang University Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
import math
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class PNDMScheduler(SchedulerMixin, ConfigMixin):
"""
`PNDMScheduler` uses pseudo numerical methods for diffusion models such as the Runge-Kutta and linear multi-step
method.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
skip_prk_steps (`bool`, defaults to `False`):
Allows the scheduler to skip the Runge-Kutta steps defined in the original paper as being required before
PLMS steps.
set_alpha_to_one (`bool`, defaults to `False`):
Each diffusion step uses the alphas product value at that step and at the previous one. For the final step
there is no previous alpha. When this option is `True` the previous alpha product is fixed to `1`,
otherwise it uses the alpha value at step 0.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process)
or `v_prediction` (see section 2.4 of [Imagen Video](https://imagen.research.google/video/paper.pdf)
paper).
timestep_spacing (`str`, defaults to `"leading"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
skip_prk_steps: bool = False,
set_alpha_to_one: bool = False,
prediction_type: str = "epsilon",
timestep_spacing: str = "leading",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
self.final_alpha_cumprod = torch.tensor(1.0) if set_alpha_to_one else self.alphas_cumprod[0]
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# For now we only support F-PNDM, i.e. the runge-kutta method
# For more information on the algorithm please take a look at the paper: https://arxiv.org/pdf/2202.09778.pdf
# mainly at formula (9), (12), (13) and the Algorithm 2.
self.pndm_order = 4
# running values
self.cur_model_output = 0
self.counter = 0
self.cur_sample = None
self.ets = []
# setable values
self.num_inference_steps = None
self._timesteps = np.arange(0, num_train_timesteps)[::-1].copy()
self.prk_timesteps = None
self.plms_timesteps = None
self.timesteps = None
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
self.num_inference_steps = num_inference_steps
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
self._timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps).round().astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
self._timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()
self._timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / self.num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
self._timesteps = np.round(np.arange(self.config.num_train_timesteps, 0, -step_ratio))[::-1].astype(
np.int64
)
self._timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
if self.config.skip_prk_steps:
# for some models like stable diffusion the prk steps can/should be skipped to
# produce better results. When using PNDM with `self.config.skip_prk_steps` the implementation
# is based on crowsonkb's PLMS sampler implementation: https://github.com/CompVis/latent-diffusion/pull/51
self.prk_timesteps = np.array([])
self.plms_timesteps = np.concatenate([self._timesteps[:-1], self._timesteps[-2:-1], self._timesteps[-1:]])[
::-1
].copy()
else:
prk_timesteps = np.array(self._timesteps[-self.pndm_order :]).repeat(2) + np.tile(
np.array([0, self.config.num_train_timesteps // num_inference_steps // 2]), self.pndm_order
)
self.prk_timesteps = (prk_timesteps[:-1].repeat(2)[1:-1])[::-1].copy()
self.plms_timesteps = self._timesteps[:-3][
::-1
].copy() # we copy to avoid having negative strides which are not supported by torch.from_numpy
timesteps = np.concatenate([self.prk_timesteps, self.plms_timesteps]).astype(np.int64)
self.timesteps = torch.from_numpy(timesteps).to(device)
self.ets = []
self.counter = 0
self.cur_model_output = 0
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
process from the learned model outputs (most often the predicted noise), and calls [`~PNDMScheduler.step_prk`]
or [`~PNDMScheduler.step_plms`] depending on the internal variable `counter`.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.counter < len(self.prk_timesteps) and not self.config.skip_prk_steps:
return self.step_prk(model_output=model_output, timestep=timestep, sample=sample, return_dict=return_dict)
else:
return self.step_plms(model_output=model_output, timestep=timestep, sample=sample, return_dict=return_dict)
def step_prk(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the Runge-Kutta method. It performs four forward passes to approximate the solution to the differential
equation.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
diff_to_prev = 0 if self.counter % 2 else self.config.num_train_timesteps // self.num_inference_steps // 2
prev_timestep = timestep - diff_to_prev
timestep = self.prk_timesteps[self.counter // 4 * 4]
if self.counter % 4 == 0:
self.cur_model_output += 1 / 6 * model_output
self.ets.append(model_output)
self.cur_sample = sample
elif (self.counter - 1) % 4 == 0:
self.cur_model_output += 1 / 3 * model_output
elif (self.counter - 2) % 4 == 0:
self.cur_model_output += 1 / 3 * model_output
elif (self.counter - 3) % 4 == 0:
model_output = self.cur_model_output + 1 / 6 * model_output
self.cur_model_output = 0
# cur_sample should not be `None`
cur_sample = self.cur_sample if self.cur_sample is not None else sample
prev_sample = self._get_prev_sample(cur_sample, timestep, prev_timestep, model_output)
self.counter += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def step_plms(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the linear multistep method. It performs one forward pass multiple times to approximate the solution.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or tuple.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if not self.config.skip_prk_steps and len(self.ets) < 3:
raise ValueError(
f"{self.__class__} can only be run AFTER scheduler has been run "
"in 'prk' mode for at least 12 iterations "
"See: https://github.com/huggingface/diffusers/blob/main/src/diffusers/pipelines/pipeline_pndm.py "
"for more information."
)
prev_timestep = timestep - self.config.num_train_timesteps // self.num_inference_steps
if self.counter != 1:
self.ets = self.ets[-3:]
self.ets.append(model_output)
else:
prev_timestep = timestep
timestep = timestep + self.config.num_train_timesteps // self.num_inference_steps
if len(self.ets) == 1 and self.counter == 0:
model_output = model_output
self.cur_sample = sample
elif len(self.ets) == 1 and self.counter == 1:
model_output = (model_output + self.ets[-1]) / 2
sample = self.cur_sample
self.cur_sample = None
elif len(self.ets) == 2:
model_output = (3 * self.ets[-1] - self.ets[-2]) / 2
elif len(self.ets) == 3:
model_output = (23 * self.ets[-1] - 16 * self.ets[-2] + 5 * self.ets[-3]) / 12
else:
model_output = (1 / 24) * (55 * self.ets[-1] - 59 * self.ets[-2] + 37 * self.ets[-3] - 9 * self.ets[-4])
prev_sample = self._get_prev_sample(sample, timestep, prev_timestep, model_output)
self.counter += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def scale_model_input(self, sample: torch.FloatTensor, *args, **kwargs) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
def _get_prev_sample(self, sample, timestep, prev_timestep, model_output):
# See formula (9) of PNDM paper https://arxiv.org/pdf/2202.09778.pdf
# this function computes x_(t−δ) using the formula of (9)
# Note that x_t needs to be added to both sides of the equation
# Notation (<variable name> -> <name in paper>
# alpha_prod_t -> α_t
# alpha_prod_t_prev -> α_(t−δ)
# beta_prod_t -> (1 - α_t)
# beta_prod_t_prev -> (1 - α_(t−δ))
# sample -> x_t
# model_output -> e_θ(x_t, t)
# prev_sample -> x_(t−δ)
alpha_prod_t = self.alphas_cumprod[timestep]
alpha_prod_t_prev = self.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.final_alpha_cumprod
beta_prod_t = 1 - alpha_prod_t
beta_prod_t_prev = 1 - alpha_prod_t_prev
if self.config.prediction_type == "v_prediction":
model_output = (alpha_prod_t**0.5) * model_output + (beta_prod_t**0.5) * sample
elif self.config.prediction_type != "epsilon":
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon` or `v_prediction`"
)
# corresponds to (α_(t−δ) - α_t) divided by
# denominator of x_t in formula (9) and plus 1
# Note: (α_(t−δ) - α_t) / (sqrt(α_t) * (sqrt(α_(t−δ)) + sqr(α_t))) =
# sqrt(α_(t−δ)) / sqrt(α_t))
sample_coeff = (alpha_prod_t_prev / alpha_prod_t) ** (0.5)
# corresponds to denominator of e_θ(x_t, t) in formula (9)
model_output_denom_coeff = alpha_prod_t * beta_prod_t_prev ** (0.5) + (
alpha_prod_t * beta_prod_t * alpha_prod_t_prev
) ** (0.5)
# full formula (9)
prev_sample = (
sample_coeff * sample - (alpha_prod_t_prev - alpha_prod_t) * model_output / model_output_denom_coeff
)
return prev_sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_pndm.py |
# Copyright 2023 TSAIL Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: This file is strongly influenced by https://github.com/LuChengTHU/dpm-solver
import math
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from ..utils.torch_utils import randn_tensor
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
def betas_for_alpha_bar(
num_diffusion_timesteps,
max_beta=0.999,
alpha_transform_type="cosine",
):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
Choose from `cosine` or `exp`
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
if alpha_transform_type == "cosine":
def alpha_bar_fn(t):
return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
elif alpha_transform_type == "exp":
def alpha_bar_fn(t):
return math.exp(t * -12.0)
else:
raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class DPMSolverMultistepScheduler(SchedulerMixin, ConfigMixin):
"""
`DPMSolverMultistepScheduler` is a fast dedicated high-order solver for diffusion ODEs.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
solver_order (`int`, defaults to 2):
The DPMSolver order which can be `1` or `2` or `3`. It is recommended to use `solver_order=2` for guided
sampling, and `solver_order=3` for unconditional sampling.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
thresholding (`bool`, defaults to `False`):
Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
as Stable Diffusion.
dynamic_thresholding_ratio (`float`, defaults to 0.995):
The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
sample_max_value (`float`, defaults to 1.0):
The threshold value for dynamic thresholding. Valid only when `thresholding=True` and
`algorithm_type="dpmsolver++"`.
algorithm_type (`str`, defaults to `dpmsolver++`):
Algorithm type for the solver; can be `dpmsolver`, `dpmsolver++`, `sde-dpmsolver` or `sde-dpmsolver++`. The
`dpmsolver` type implements the algorithms in the [DPMSolver](https://huggingface.co/papers/2206.00927)
paper, and the `dpmsolver++` type implements the algorithms in the
[DPMSolver++](https://huggingface.co/papers/2211.01095) paper. It is recommended to use `dpmsolver++` or
`sde-dpmsolver++` with `solver_order=2` for guided sampling like in Stable Diffusion.
solver_type (`str`, defaults to `midpoint`):
Solver type for the second-order solver; can be `midpoint` or `heun`. The solver type slightly affects the
sample quality, especially for a small number of steps. It is recommended to use `midpoint` solvers.
lower_order_final (`bool`, defaults to `True`):
Whether to use lower-order solvers in the final steps. Only valid for < 15 inference steps. This can
stabilize the sampling of DPMSolver for steps < 15, especially for steps <= 10.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
lambda_min_clipped (`float`, defaults to `-inf`):
Clipping threshold for the minimum value of `lambda(t)` for numerical stability. This is critical for the
cosine (`squaredcos_cap_v2`) noise schedule.
variance_type (`str`, *optional*):
Set to "learned" or "learned_range" for diffusion models that predict variance. If set, the model's output
contains the predicted Gaussian variance.
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
solver_order: int = 2,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
sample_max_value: float = 1.0,
algorithm_type: str = "dpmsolver++",
solver_type: str = "midpoint",
lower_order_final: bool = True,
use_karras_sigmas: Optional[bool] = False,
lambda_min_clipped: float = -float("inf"),
variance_type: Optional[str] = None,
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# Currently we only support VP-type noise schedule
self.alpha_t = torch.sqrt(self.alphas_cumprod)
self.sigma_t = torch.sqrt(1 - self.alphas_cumprod)
self.lambda_t = torch.log(self.alpha_t) - torch.log(self.sigma_t)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
# settings for DPM-Solver
if algorithm_type not in ["dpmsolver", "dpmsolver++", "sde-dpmsolver", "sde-dpmsolver++"]:
if algorithm_type == "deis":
self.register_to_config(algorithm_type="dpmsolver++")
else:
raise NotImplementedError(f"{algorithm_type} does is not implemented for {self.__class__}")
if solver_type not in ["midpoint", "heun"]:
if solver_type in ["logrho", "bh1", "bh2"]:
self.register_to_config(solver_type="midpoint")
else:
raise NotImplementedError(f"{solver_type} does is not implemented for {self.__class__}")
# setable values
self.num_inference_steps = None
timesteps = np.linspace(0, num_train_timesteps - 1, num_train_timesteps, dtype=np.float32)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps)
self.model_outputs = [None] * solver_order
self.lower_order_nums = 0
def set_timesteps(self, num_inference_steps: int = None, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
# Clipping the minimum of all lambda(t) for numerical stability.
# This is critical for cosine (squaredcos_cap_v2) noise schedule.
clipped_idx = torch.searchsorted(torch.flip(self.lambda_t, [0]), self.config.lambda_min_clipped)
last_timestep = ((self.config.num_train_timesteps - clipped_idx).numpy()).item()
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, last_timestep - 1, num_inference_steps + 1).round()[::-1][:-1].copy().astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = last_timestep // (num_inference_steps + 1)
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps + 1) * step_ratio).round()[::-1][:-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.arange(last_timestep, 0, -step_ratio).round().copy().astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
if self.config.use_karras_sigmas:
log_sigmas = np.log(sigmas)
sigmas = self._convert_to_karras(in_sigmas=sigmas, num_inference_steps=num_inference_steps)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas]).round()
timesteps = np.flip(timesteps).copy().astype(np.int64)
self.sigmas = torch.from_numpy(sigmas)
# when num_inference_steps == num_train_timesteps, we can end up with
# duplicates in timesteps.
_, unique_indices = np.unique(timesteps, return_index=True)
timesteps = timesteps[np.sort(unique_indices)]
self.timesteps = torch.from_numpy(timesteps).to(device)
self.num_inference_steps = len(timesteps)
self.model_outputs = [
None,
] * self.config.solver_order
self.lower_order_nums = 0
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._sigma_to_t
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._convert_to_karras
def _convert_to_karras(self, in_sigmas: torch.FloatTensor, num_inference_steps) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
def convert_model_output(
self, model_output: torch.FloatTensor, timestep: int, sample: torch.FloatTensor
) -> torch.FloatTensor:
"""
Convert the model output to the corresponding type the DPMSolver/DPMSolver++ algorithm needs. DPM-Solver is
designed to discretize an integral of the noise prediction model, and DPM-Solver++ is designed to discretize an
integral of the data prediction model.
<Tip>
The algorithm and model type are decoupled. You can use either DPMSolver or DPMSolver++ for both noise
prediction and data prediction models.
</Tip>
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The converted model output.
"""
# DPM-Solver++ needs to solve an integral of the data prediction model.
if self.config.algorithm_type in ["dpmsolver++", "sde-dpmsolver++"]:
if self.config.prediction_type == "epsilon":
# DPM-Solver and DPM-Solver++ only need the "mean" output.
if self.config.variance_type in ["learned", "learned_range"]:
model_output = model_output[:, :3]
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = (sample - sigma_t * model_output) / alpha_t
elif self.config.prediction_type == "sample":
x0_pred = model_output
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = alpha_t * sample - sigma_t * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the DPMSolverMultistepScheduler."
)
if self.config.thresholding:
x0_pred = self._threshold_sample(x0_pred)
return x0_pred
# DPM-Solver needs to solve an integral of the noise prediction model.
elif self.config.algorithm_type in ["dpmsolver", "sde-dpmsolver"]:
if self.config.prediction_type == "epsilon":
# DPM-Solver and DPM-Solver++ only need the "mean" output.
if self.config.variance_type in ["learned", "learned_range"]:
epsilon = model_output[:, :3]
else:
epsilon = model_output
elif self.config.prediction_type == "sample":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = (sample - alpha_t * model_output) / sigma_t
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = alpha_t * model_output + sigma_t * sample
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the DPMSolverMultistepScheduler."
)
if self.config.thresholding:
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = (sample - sigma_t * epsilon) / alpha_t
x0_pred = self._threshold_sample(x0_pred)
epsilon = (sample - alpha_t * x0_pred) / sigma_t
return epsilon
def dpm_solver_first_order_update(
self,
model_output: torch.FloatTensor,
timestep: int,
prev_timestep: int,
sample: torch.FloatTensor,
noise: Optional[torch.FloatTensor] = None,
) -> torch.FloatTensor:
"""
One step for the first-order DPMSolver (equivalent to DDIM).
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
lambda_t, lambda_s = self.lambda_t[prev_timestep], self.lambda_t[timestep]
alpha_t, alpha_s = self.alpha_t[prev_timestep], self.alpha_t[timestep]
sigma_t, sigma_s = self.sigma_t[prev_timestep], self.sigma_t[timestep]
h = lambda_t - lambda_s
if self.config.algorithm_type == "dpmsolver++":
x_t = (sigma_t / sigma_s) * sample - (alpha_t * (torch.exp(-h) - 1.0)) * model_output
elif self.config.algorithm_type == "dpmsolver":
x_t = (alpha_t / alpha_s) * sample - (sigma_t * (torch.exp(h) - 1.0)) * model_output
elif self.config.algorithm_type == "sde-dpmsolver++":
assert noise is not None
x_t = (
(sigma_t / sigma_s * torch.exp(-h)) * sample
+ (alpha_t * (1 - torch.exp(-2.0 * h))) * model_output
+ sigma_t * torch.sqrt(1.0 - torch.exp(-2 * h)) * noise
)
elif self.config.algorithm_type == "sde-dpmsolver":
assert noise is not None
x_t = (
(alpha_t / alpha_s) * sample
- 2.0 * (sigma_t * (torch.exp(h) - 1.0)) * model_output
+ sigma_t * torch.sqrt(torch.exp(2 * h) - 1.0) * noise
)
return x_t
def multistep_dpm_solver_second_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
noise: Optional[torch.FloatTensor] = None,
) -> torch.FloatTensor:
"""
One step for the second-order multistep DPMSolver.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1 = prev_timestep, timestep_list[-1], timestep_list[-2]
m0, m1 = model_output_list[-1], model_output_list[-2]
lambda_t, lambda_s0, lambda_s1 = self.lambda_t[t], self.lambda_t[s0], self.lambda_t[s1]
alpha_t, alpha_s0 = self.alpha_t[t], self.alpha_t[s0]
sigma_t, sigma_s0 = self.sigma_t[t], self.sigma_t[s0]
h, h_0 = lambda_t - lambda_s0, lambda_s0 - lambda_s1
r0 = h_0 / h
D0, D1 = m0, (1.0 / r0) * (m0 - m1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2211.01095 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
- 0.5 * (alpha_t * (torch.exp(-h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
+ (alpha_t * ((torch.exp(-h) - 1.0) / h + 1.0)) * D1
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
if self.config.solver_type == "midpoint":
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- 0.5 * (sigma_t * (torch.exp(h) - 1.0)) * D1
)
elif self.config.solver_type == "heun":
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1
)
elif self.config.algorithm_type == "sde-dpmsolver++":
assert noise is not None
if self.config.solver_type == "midpoint":
x_t = (
(sigma_t / sigma_s0 * torch.exp(-h)) * sample
+ (alpha_t * (1 - torch.exp(-2.0 * h))) * D0
+ 0.5 * (alpha_t * (1 - torch.exp(-2.0 * h))) * D1
+ sigma_t * torch.sqrt(1.0 - torch.exp(-2 * h)) * noise
)
elif self.config.solver_type == "heun":
x_t = (
(sigma_t / sigma_s0 * torch.exp(-h)) * sample
+ (alpha_t * (1 - torch.exp(-2.0 * h))) * D0
+ (alpha_t * ((1.0 - torch.exp(-2.0 * h)) / (-2.0 * h) + 1.0)) * D1
+ sigma_t * torch.sqrt(1.0 - torch.exp(-2 * h)) * noise
)
elif self.config.algorithm_type == "sde-dpmsolver":
assert noise is not None
if self.config.solver_type == "midpoint":
x_t = (
(alpha_t / alpha_s0) * sample
- 2.0 * (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * (torch.exp(h) - 1.0)) * D1
+ sigma_t * torch.sqrt(torch.exp(2 * h) - 1.0) * noise
)
elif self.config.solver_type == "heun":
x_t = (
(alpha_t / alpha_s0) * sample
- 2.0 * (sigma_t * (torch.exp(h) - 1.0)) * D0
- 2.0 * (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1
+ sigma_t * torch.sqrt(torch.exp(2 * h) - 1.0) * noise
)
return x_t
def multistep_dpm_solver_third_order_update(
self,
model_output_list: List[torch.FloatTensor],
timestep_list: List[int],
prev_timestep: int,
sample: torch.FloatTensor,
) -> torch.FloatTensor:
"""
One step for the third-order multistep DPMSolver.
Args:
model_output_list (`List[torch.FloatTensor]`):
The direct outputs from learned diffusion model at current and latter timesteps.
timestep (`int`):
The current and latter discrete timestep in the diffusion chain.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by diffusion process.
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
t, s0, s1, s2 = prev_timestep, timestep_list[-1], timestep_list[-2], timestep_list[-3]
m0, m1, m2 = model_output_list[-1], model_output_list[-2], model_output_list[-3]
lambda_t, lambda_s0, lambda_s1, lambda_s2 = (
self.lambda_t[t],
self.lambda_t[s0],
self.lambda_t[s1],
self.lambda_t[s2],
)
alpha_t, alpha_s0 = self.alpha_t[t], self.alpha_t[s0]
sigma_t, sigma_s0 = self.sigma_t[t], self.sigma_t[s0]
h, h_0, h_1 = lambda_t - lambda_s0, lambda_s0 - lambda_s1, lambda_s1 - lambda_s2
r0, r1 = h_0 / h, h_1 / h
D0 = m0
D1_0, D1_1 = (1.0 / r0) * (m0 - m1), (1.0 / r1) * (m1 - m2)
D1 = D1_0 + (r0 / (r0 + r1)) * (D1_0 - D1_1)
D2 = (1.0 / (r0 + r1)) * (D1_0 - D1_1)
if self.config.algorithm_type == "dpmsolver++":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
x_t = (
(sigma_t / sigma_s0) * sample
- (alpha_t * (torch.exp(-h) - 1.0)) * D0
+ (alpha_t * ((torch.exp(-h) - 1.0) / h + 1.0)) * D1
- (alpha_t * ((torch.exp(-h) - 1.0 + h) / h**2 - 0.5)) * D2
)
elif self.config.algorithm_type == "dpmsolver":
# See https://arxiv.org/abs/2206.00927 for detailed derivations
x_t = (
(alpha_t / alpha_s0) * sample
- (sigma_t * (torch.exp(h) - 1.0)) * D0
- (sigma_t * ((torch.exp(h) - 1.0) / h - 1.0)) * D1
- (sigma_t * ((torch.exp(h) - 1.0 - h) / h**2 - 0.5)) * D2
)
return x_t
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
generator=None,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the multistep DPMSolver.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
generator (`torch.Generator`, *optional*):
A random number generator.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
step_index = (self.timesteps == timestep).nonzero()
if len(step_index) == 0:
step_index = len(self.timesteps) - 1
else:
step_index = step_index.item()
prev_timestep = 0 if step_index == len(self.timesteps) - 1 else self.timesteps[step_index + 1]
lower_order_final = (
(step_index == len(self.timesteps) - 1) and self.config.lower_order_final and len(self.timesteps) < 15
)
lower_order_second = (
(step_index == len(self.timesteps) - 2) and self.config.lower_order_final and len(self.timesteps) < 15
)
model_output = self.convert_model_output(model_output, timestep, sample)
for i in range(self.config.solver_order - 1):
self.model_outputs[i] = self.model_outputs[i + 1]
self.model_outputs[-1] = model_output
if self.config.algorithm_type in ["sde-dpmsolver", "sde-dpmsolver++"]:
noise = randn_tensor(
model_output.shape, generator=generator, device=model_output.device, dtype=model_output.dtype
)
else:
noise = None
if self.config.solver_order == 1 or self.lower_order_nums < 1 or lower_order_final:
prev_sample = self.dpm_solver_first_order_update(
model_output, timestep, prev_timestep, sample, noise=noise
)
elif self.config.solver_order == 2 or self.lower_order_nums < 2 or lower_order_second:
timestep_list = [self.timesteps[step_index - 1], timestep]
prev_sample = self.multistep_dpm_solver_second_order_update(
self.model_outputs, timestep_list, prev_timestep, sample, noise=noise
)
else:
timestep_list = [self.timesteps[step_index - 2], self.timesteps[step_index - 1], timestep]
prev_sample = self.multistep_dpm_solver_third_order_update(
self.model_outputs, timestep_list, prev_timestep, sample
)
if self.lower_order_nums < self.config.solver_order:
self.lower_order_nums += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def scale_model_input(self, sample: torch.FloatTensor, *args, **kwargs) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_dpmsolver_multistep.py |
# Copyright 2023 TSAIL Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# DISCLAIMER: check https://arxiv.org/abs/2302.04867 and https://github.com/wl-zhao/UniPC for more info
# The codebase is modified based on https://github.com/huggingface/diffusers/blob/main/src/diffusers/schedulers/scheduling_dpmsolver_multistep.py
import math
from typing import List, Optional, Tuple, Union
import numpy as np
import torch
from ..configuration_utils import ConfigMixin, register_to_config
from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin, SchedulerOutput
def betas_for_alpha_bar(num_diffusion_timesteps, max_beta=0.999):
"""
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
(1-beta) over time from t = [0,1].
Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
to that part of the diffusion process.
Args:
num_diffusion_timesteps (`int`): the number of betas to produce.
max_beta (`float`): the maximum beta to use; use values lower than 1 to
prevent singularities.
Returns:
betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
"""
def alpha_bar(time_step):
return math.cos((time_step + 0.008) / 1.008 * math.pi / 2) ** 2
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar(t2) / alpha_bar(t1), max_beta))
return torch.tensor(betas, dtype=torch.float32)
class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
"""
`UniPCMultistepScheduler` is a training-free framework designed for the fast sampling of diffusion models.
This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
methods the library implements for all schedulers such as loading and saving.
Args:
num_train_timesteps (`int`, defaults to 1000):
The number of diffusion steps to train the model.
beta_start (`float`, defaults to 0.0001):
The starting `beta` value of inference.
beta_end (`float`, defaults to 0.02):
The final `beta` value.
beta_schedule (`str`, defaults to `"linear"`):
The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
`linear`, `scaled_linear`, or `squaredcos_cap_v2`.
trained_betas (`np.ndarray`, *optional*):
Pass an array of betas directly to the constructor to bypass `beta_start` and `beta_end`.
solver_order (`int`, default `2`):
The UniPC order which can be any positive integer. The effective order of accuracy is `solver_order + 1`
due to the UniC. It is recommended to use `solver_order=2` for guided sampling, and `solver_order=3` for
unconditional sampling.
prediction_type (`str`, defaults to `epsilon`, *optional*):
Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
`sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
Video](https://imagen.research.google/video/paper.pdf) paper).
thresholding (`bool`, defaults to `False`):
Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
as Stable Diffusion.
dynamic_thresholding_ratio (`float`, defaults to 0.995):
The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
sample_max_value (`float`, defaults to 1.0):
The threshold value for dynamic thresholding. Valid only when `thresholding=True` and `predict_x0=True`.
predict_x0 (`bool`, defaults to `True`):
Whether to use the updating algorithm on the predicted x0.
solver_type (`str`, default `bh2`):
Solver type for UniPC. It is recommended to use `bh1` for unconditional sampling when steps < 10, and `bh2`
otherwise.
lower_order_final (`bool`, default `True`):
Whether to use lower-order solvers in the final steps. Only valid for < 15 inference steps. This can
stabilize the sampling of DPMSolver for steps < 15, especially for steps <= 10.
disable_corrector (`list`, default `[]`):
Decides which step to disable the corrector to mitigate the misalignment between `epsilon_theta(x_t, c)`
and `epsilon_theta(x_t^c, c)` which can influence convergence for a large guidance scale. Corrector is
usually disabled during the first few steps.
solver_p (`SchedulerMixin`, default `None`):
Any other scheduler that if specified, the algorithm becomes `solver_p + UniC`.
use_karras_sigmas (`bool`, *optional*, defaults to `False`):
Whether to use Karras sigmas for step sizes in the noise schedule during the sampling process. If `True`,
the sigmas are determined according to a sequence of noise levels {σi}.
timestep_spacing (`str`, defaults to `"linspace"`):
The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
steps_offset (`int`, defaults to 0):
An offset added to the inference steps. You can use a combination of `offset=1` and
`set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
Diffusion.
"""
_compatibles = [e.name for e in KarrasDiffusionSchedulers]
order = 1
@register_to_config
def __init__(
self,
num_train_timesteps: int = 1000,
beta_start: float = 0.0001,
beta_end: float = 0.02,
beta_schedule: str = "linear",
trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
solver_order: int = 2,
prediction_type: str = "epsilon",
thresholding: bool = False,
dynamic_thresholding_ratio: float = 0.995,
sample_max_value: float = 1.0,
predict_x0: bool = True,
solver_type: str = "bh2",
lower_order_final: bool = True,
disable_corrector: List[int] = [],
solver_p: SchedulerMixin = None,
use_karras_sigmas: Optional[bool] = False,
timestep_spacing: str = "linspace",
steps_offset: int = 0,
):
if trained_betas is not None:
self.betas = torch.tensor(trained_betas, dtype=torch.float32)
elif beta_schedule == "linear":
self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
elif beta_schedule == "scaled_linear":
# this schedule is very specific to the latent diffusion model.
self.betas = (
torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
)
elif beta_schedule == "squaredcos_cap_v2":
# Glide cosine schedule
self.betas = betas_for_alpha_bar(num_train_timesteps)
else:
raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
self.alphas = 1.0 - self.betas
self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
# Currently we only support VP-type noise schedule
self.alpha_t = torch.sqrt(self.alphas_cumprod)
self.sigma_t = torch.sqrt(1 - self.alphas_cumprod)
self.lambda_t = torch.log(self.alpha_t) - torch.log(self.sigma_t)
# standard deviation of the initial noise distribution
self.init_noise_sigma = 1.0
if solver_type not in ["bh1", "bh2"]:
if solver_type in ["midpoint", "heun", "logrho"]:
self.register_to_config(solver_type="bh2")
else:
raise NotImplementedError(f"{solver_type} does is not implemented for {self.__class__}")
self.predict_x0 = predict_x0
# setable values
self.num_inference_steps = None
timesteps = np.linspace(0, num_train_timesteps - 1, num_train_timesteps, dtype=np.float32)[::-1].copy()
self.timesteps = torch.from_numpy(timesteps)
self.model_outputs = [None] * solver_order
self.timestep_list = [None] * solver_order
self.lower_order_nums = 0
self.disable_corrector = disable_corrector
self.solver_p = solver_p
self.last_sample = None
def set_timesteps(self, num_inference_steps: int, device: Union[str, torch.device] = None):
"""
Sets the discrete timesteps used for the diffusion chain (to be run before inference).
Args:
num_inference_steps (`int`):
The number of diffusion steps used when generating samples with a pre-trained model.
device (`str` or `torch.device`, *optional*):
The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
"""
# "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
if self.config.timestep_spacing == "linspace":
timesteps = (
np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps + 1)
.round()[::-1][:-1]
.copy()
.astype(np.int64)
)
elif self.config.timestep_spacing == "leading":
step_ratio = self.config.num_train_timesteps // (num_inference_steps + 1)
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = (np.arange(0, num_inference_steps + 1) * step_ratio).round()[::-1][:-1].copy().astype(np.int64)
timesteps += self.config.steps_offset
elif self.config.timestep_spacing == "trailing":
step_ratio = self.config.num_train_timesteps / num_inference_steps
# creates integer timesteps by multiplying by ratio
# casting to int to avoid issues when num_inference_step is power of 3
timesteps = np.arange(self.config.num_train_timesteps, 0, -step_ratio).round().copy().astype(np.int64)
timesteps -= 1
else:
raise ValueError(
f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
)
sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)
if self.config.use_karras_sigmas:
log_sigmas = np.log(sigmas)
sigmas = self._convert_to_karras(in_sigmas=sigmas, num_inference_steps=num_inference_steps)
timesteps = np.array([self._sigma_to_t(sigma, log_sigmas) for sigma in sigmas]).round()
timesteps = np.flip(timesteps).copy().astype(np.int64)
self.sigmas = torch.from_numpy(sigmas)
# when num_inference_steps == num_train_timesteps, we can end up with
# duplicates in timesteps.
_, unique_indices = np.unique(timesteps, return_index=True)
timesteps = timesteps[np.sort(unique_indices)]
self.timesteps = torch.from_numpy(timesteps).to(device)
self.num_inference_steps = len(timesteps)
self.model_outputs = [
None,
] * self.config.solver_order
self.lower_order_nums = 0
self.last_sample = None
if self.solver_p:
self.solver_p.set_timesteps(self.num_inference_steps, device=device)
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
"""
"Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
pixels from saturation at each step. We find that dynamic thresholding results in significantly better
photorealism as well as better image-text alignment, especially when using very large guidance weights."
https://arxiv.org/abs/2205.11487
"""
dtype = sample.dtype
batch_size, channels, height, width = sample.shape
if dtype not in (torch.float32, torch.float64):
sample = sample.float() # upcast for quantile calculation, and clamp not implemented for cpu half
# Flatten sample for doing quantile calculation along each image
sample = sample.reshape(batch_size, channels * height * width)
abs_sample = sample.abs() # "a certain percentile absolute pixel value"
s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
s = torch.clamp(
s, min=1, max=self.config.sample_max_value
) # When clamped to min=1, equivalent to standard clipping to [-1, 1]
s = s.unsqueeze(1) # (batch_size, 1) because clamp will broadcast along dim=0
sample = torch.clamp(sample, -s, s) / s # "we threshold xt0 to the range [-s, s] and then divide by s"
sample = sample.reshape(batch_size, channels, height, width)
sample = sample.to(dtype)
return sample
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._sigma_to_t
def _sigma_to_t(self, sigma, log_sigmas):
# get log sigma
log_sigma = np.log(sigma)
# get distribution
dists = log_sigma - log_sigmas[:, np.newaxis]
# get sigmas range
low_idx = np.cumsum((dists >= 0), axis=0).argmax(axis=0).clip(max=log_sigmas.shape[0] - 2)
high_idx = low_idx + 1
low = log_sigmas[low_idx]
high = log_sigmas[high_idx]
# interpolate sigmas
w = (low - log_sigma) / (low - high)
w = np.clip(w, 0, 1)
# transform interpolation to time range
t = (1 - w) * low_idx + w * high_idx
t = t.reshape(sigma.shape)
return t
# Copied from diffusers.schedulers.scheduling_euler_discrete.EulerDiscreteScheduler._convert_to_karras
def _convert_to_karras(self, in_sigmas: torch.FloatTensor, num_inference_steps) -> torch.FloatTensor:
"""Constructs the noise schedule of Karras et al. (2022)."""
sigma_min: float = in_sigmas[-1].item()
sigma_max: float = in_sigmas[0].item()
rho = 7.0 # 7.0 is the value used in the paper
ramp = np.linspace(0, 1, num_inference_steps)
min_inv_rho = sigma_min ** (1 / rho)
max_inv_rho = sigma_max ** (1 / rho)
sigmas = (max_inv_rho + ramp * (min_inv_rho - max_inv_rho)) ** rho
return sigmas
def convert_model_output(
self, model_output: torch.FloatTensor, timestep: int, sample: torch.FloatTensor
) -> torch.FloatTensor:
r"""
Convert the model output to the corresponding type the UniPC algorithm needs.
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
Returns:
`torch.FloatTensor`:
The converted model output.
"""
if self.predict_x0:
if self.config.prediction_type == "epsilon":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = (sample - sigma_t * model_output) / alpha_t
elif self.config.prediction_type == "sample":
x0_pred = model_output
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
x0_pred = alpha_t * sample - sigma_t * model_output
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the UniPCMultistepScheduler."
)
if self.config.thresholding:
x0_pred = self._threshold_sample(x0_pred)
return x0_pred
else:
if self.config.prediction_type == "epsilon":
return model_output
elif self.config.prediction_type == "sample":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = (sample - alpha_t * model_output) / sigma_t
return epsilon
elif self.config.prediction_type == "v_prediction":
alpha_t, sigma_t = self.alpha_t[timestep], self.sigma_t[timestep]
epsilon = alpha_t * model_output + sigma_t * sample
return epsilon
else:
raise ValueError(
f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample`, or"
" `v_prediction` for the UniPCMultistepScheduler."
)
def multistep_uni_p_bh_update(
self,
model_output: torch.FloatTensor,
prev_timestep: int,
sample: torch.FloatTensor,
order: int,
) -> torch.FloatTensor:
"""
One step for the UniP (B(h) version). Alternatively, `self.solver_p` is used if is specified.
Args:
model_output (`torch.FloatTensor`):
The direct output from the learned diffusion model at the current timestep.
prev_timestep (`int`):
The previous discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
order (`int`):
The order of UniP at this timestep (corresponds to the *p* in UniPC-p).
Returns:
`torch.FloatTensor`:
The sample tensor at the previous timestep.
"""
timestep_list = self.timestep_list
model_output_list = self.model_outputs
s0, t = self.timestep_list[-1], prev_timestep
m0 = model_output_list[-1]
x = sample
if self.solver_p:
x_t = self.solver_p.step(model_output, s0, x).prev_sample
return x_t
lambda_t, lambda_s0 = self.lambda_t[t], self.lambda_t[s0]
alpha_t, alpha_s0 = self.alpha_t[t], self.alpha_t[s0]
sigma_t, sigma_s0 = self.sigma_t[t], self.sigma_t[s0]
h = lambda_t - lambda_s0
device = sample.device
rks = []
D1s = []
for i in range(1, order):
si = timestep_list[-(i + 1)]
mi = model_output_list[-(i + 1)]
lambda_si = self.lambda_t[si]
rk = (lambda_si - lambda_s0) / h
rks.append(rk)
D1s.append((mi - m0) / rk)
rks.append(1.0)
rks = torch.tensor(rks, device=device)
R = []
b = []
hh = -h if self.predict_x0 else h
h_phi_1 = torch.expm1(hh) # h\phi_1(h) = e^h - 1
h_phi_k = h_phi_1 / hh - 1
factorial_i = 1
if self.config.solver_type == "bh1":
B_h = hh
elif self.config.solver_type == "bh2":
B_h = torch.expm1(hh)
else:
raise NotImplementedError()
for i in range(1, order + 1):
R.append(torch.pow(rks, i - 1))
b.append(h_phi_k * factorial_i / B_h)
factorial_i *= i + 1
h_phi_k = h_phi_k / hh - 1 / factorial_i
R = torch.stack(R)
b = torch.tensor(b, device=device)
if len(D1s) > 0:
D1s = torch.stack(D1s, dim=1) # (B, K)
# for order 2, we use a simplified version
if order == 2:
rhos_p = torch.tensor([0.5], dtype=x.dtype, device=device)
else:
rhos_p = torch.linalg.solve(R[:-1, :-1], b[:-1])
else:
D1s = None
if self.predict_x0:
x_t_ = sigma_t / sigma_s0 * x - alpha_t * h_phi_1 * m0
if D1s is not None:
pred_res = torch.einsum("k,bkchw->bchw", rhos_p, D1s)
else:
pred_res = 0
x_t = x_t_ - alpha_t * B_h * pred_res
else:
x_t_ = alpha_t / alpha_s0 * x - sigma_t * h_phi_1 * m0
if D1s is not None:
pred_res = torch.einsum("k,bkchw->bchw", rhos_p, D1s)
else:
pred_res = 0
x_t = x_t_ - sigma_t * B_h * pred_res
x_t = x_t.to(x.dtype)
return x_t
def multistep_uni_c_bh_update(
self,
this_model_output: torch.FloatTensor,
this_timestep: int,
last_sample: torch.FloatTensor,
this_sample: torch.FloatTensor,
order: int,
) -> torch.FloatTensor:
"""
One step for the UniC (B(h) version).
Args:
this_model_output (`torch.FloatTensor`):
The model outputs at `x_t`.
this_timestep (`int`):
The current timestep `t`.
last_sample (`torch.FloatTensor`):
The generated sample before the last predictor `x_{t-1}`.
this_sample (`torch.FloatTensor`):
The generated sample after the last predictor `x_{t}`.
order (`int`):
The `p` of UniC-p at this step. The effective order of accuracy should be `order + 1`.
Returns:
`torch.FloatTensor`:
The corrected sample tensor at the current timestep.
"""
timestep_list = self.timestep_list
model_output_list = self.model_outputs
s0, t = timestep_list[-1], this_timestep
m0 = model_output_list[-1]
x = last_sample
x_t = this_sample
model_t = this_model_output
lambda_t, lambda_s0 = self.lambda_t[t], self.lambda_t[s0]
alpha_t, alpha_s0 = self.alpha_t[t], self.alpha_t[s0]
sigma_t, sigma_s0 = self.sigma_t[t], self.sigma_t[s0]
h = lambda_t - lambda_s0
device = this_sample.device
rks = []
D1s = []
for i in range(1, order):
si = timestep_list[-(i + 1)]
mi = model_output_list[-(i + 1)]
lambda_si = self.lambda_t[si]
rk = (lambda_si - lambda_s0) / h
rks.append(rk)
D1s.append((mi - m0) / rk)
rks.append(1.0)
rks = torch.tensor(rks, device=device)
R = []
b = []
hh = -h if self.predict_x0 else h
h_phi_1 = torch.expm1(hh) # h\phi_1(h) = e^h - 1
h_phi_k = h_phi_1 / hh - 1
factorial_i = 1
if self.config.solver_type == "bh1":
B_h = hh
elif self.config.solver_type == "bh2":
B_h = torch.expm1(hh)
else:
raise NotImplementedError()
for i in range(1, order + 1):
R.append(torch.pow(rks, i - 1))
b.append(h_phi_k * factorial_i / B_h)
factorial_i *= i + 1
h_phi_k = h_phi_k / hh - 1 / factorial_i
R = torch.stack(R)
b = torch.tensor(b, device=device)
if len(D1s) > 0:
D1s = torch.stack(D1s, dim=1)
else:
D1s = None
# for order 1, we use a simplified version
if order == 1:
rhos_c = torch.tensor([0.5], dtype=x.dtype, device=device)
else:
rhos_c = torch.linalg.solve(R, b)
if self.predict_x0:
x_t_ = sigma_t / sigma_s0 * x - alpha_t * h_phi_1 * m0
if D1s is not None:
corr_res = torch.einsum("k,bkchw->bchw", rhos_c[:-1], D1s)
else:
corr_res = 0
D1_t = model_t - m0
x_t = x_t_ - alpha_t * B_h * (corr_res + rhos_c[-1] * D1_t)
else:
x_t_ = alpha_t / alpha_s0 * x - sigma_t * h_phi_1 * m0
if D1s is not None:
corr_res = torch.einsum("k,bkchw->bchw", rhos_c[:-1], D1s)
else:
corr_res = 0
D1_t = model_t - m0
x_t = x_t_ - sigma_t * B_h * (corr_res + rhos_c[-1] * D1_t)
x_t = x_t.to(x.dtype)
return x_t
def step(
self,
model_output: torch.FloatTensor,
timestep: int,
sample: torch.FloatTensor,
return_dict: bool = True,
) -> Union[SchedulerOutput, Tuple]:
"""
Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the multistep UniPC.
Args:
model_output (`torch.FloatTensor`):
The direct output from learned diffusion model.
timestep (`int`):
The current discrete timestep in the diffusion chain.
sample (`torch.FloatTensor`):
A current instance of a sample created by the diffusion process.
return_dict (`bool`):
Whether or not to return a [`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`.
Returns:
[`~schedulers.scheduling_utils.SchedulerOutput`] or `tuple`:
If return_dict is `True`, [`~schedulers.scheduling_utils.SchedulerOutput`] is returned, otherwise a
tuple is returned where the first element is the sample tensor.
"""
if self.num_inference_steps is None:
raise ValueError(
"Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
)
if isinstance(timestep, torch.Tensor):
timestep = timestep.to(self.timesteps.device)
step_index = (self.timesteps == timestep).nonzero()
if len(step_index) == 0:
step_index = len(self.timesteps) - 1
else:
step_index = step_index.item()
use_corrector = (
step_index > 0 and step_index - 1 not in self.disable_corrector and self.last_sample is not None
)
model_output_convert = self.convert_model_output(model_output, timestep, sample)
if use_corrector:
sample = self.multistep_uni_c_bh_update(
this_model_output=model_output_convert,
this_timestep=timestep,
last_sample=self.last_sample,
this_sample=sample,
order=self.this_order,
)
# now prepare to run the predictor
prev_timestep = 0 if step_index == len(self.timesteps) - 1 else self.timesteps[step_index + 1]
for i in range(self.config.solver_order - 1):
self.model_outputs[i] = self.model_outputs[i + 1]
self.timestep_list[i] = self.timestep_list[i + 1]
self.model_outputs[-1] = model_output_convert
self.timestep_list[-1] = timestep
if self.config.lower_order_final:
this_order = min(self.config.solver_order, len(self.timesteps) - step_index)
else:
this_order = self.config.solver_order
self.this_order = min(this_order, self.lower_order_nums + 1) # warmup for multistep
assert self.this_order > 0
self.last_sample = sample
prev_sample = self.multistep_uni_p_bh_update(
model_output=model_output, # pass the original non-converted model output, in case solver-p is used
prev_timestep=prev_timestep,
sample=sample,
order=self.this_order,
)
if self.lower_order_nums < self.config.solver_order:
self.lower_order_nums += 1
if not return_dict:
return (prev_sample,)
return SchedulerOutput(prev_sample=prev_sample)
def scale_model_input(self, sample: torch.FloatTensor, *args, **kwargs) -> torch.FloatTensor:
"""
Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
current timestep.
Args:
sample (`torch.FloatTensor`):
The input sample.
Returns:
`torch.FloatTensor`:
A scaled input sample.
"""
return sample
# Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
def add_noise(
self,
original_samples: torch.FloatTensor,
noise: torch.FloatTensor,
timesteps: torch.IntTensor,
) -> torch.FloatTensor:
# Make sure alphas_cumprod and timestep have same device and dtype as original_samples
alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
timesteps = timesteps.to(original_samples.device)
sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
sqrt_alpha_prod = sqrt_alpha_prod.flatten()
while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
return noisy_samples
def __len__(self):
return self.config.num_train_timesteps
| diffusers-main | src/diffusers/schedulers/scheduling_unipc_multistep.py |
# This example shows how the candle Python api can be used to replicate llama.cpp.
import sys
import candle
MAX_SEQ_LEN = 4096
def masked_fill(on_false, mask, on_true):
shape = mask.shape
on_true = candle.tensor(on_true).broadcast_as(shape)
return mask.where_cond(on_true, on_false)
class RmsNorm:
def __init__(self, qtensor):
self.weight = qtensor.dequantize()
def __call__(self, x):
b_size, seq_len, hidden_size = x.shape
norm_x = x.sqr().sum_keepdim(2) / hidden_size
x_normed = x.broadcast_div((norm_x + 1e-5).sqrt())
return x_normed.broadcast_mul(self.weight)
class QuantizedLayer:
def __init__(self, layer_idx, hparams, all_tensors, cos_sin):
p = f"layers.{layer_idx}"
self.attention_wq = all_tensors[f"{p}.attention.wq.weight"]
self.attention_wk = all_tensors[f"{p}.attention.wk.weight"]
self.attention_wv = all_tensors[f"{p}.attention.wv.weight"]
self.attention_wo = all_tensors[f"{p}.attention.wo.weight"]
self.ffw1 = all_tensors[f"{p}.feed_forward.w1.weight"]
self.ffw2 = all_tensors[f"{p}.feed_forward.w2.weight"]
self.ffw3 = all_tensors[f"{p}.feed_forward.w3.weight"]
self.attn_norm = RmsNorm(all_tensors[f"{p}.attention_norm.weight"])
self.ffn_norm = RmsNorm(all_tensors[f"{p}.ffn_norm.weight"])
self.n_head = hparams["n_head"]
self.n_kv_head = self.n_head
self.head_dim = hparams["n_embd"] // self.n_head
self.kv_cache = None
self.cos = cos_sin[0]
self.sin = cos_sin[1]
def __call__(self, x, mask, index_pos):
residual = x
x = self.attn_norm(x)
attn = self.forward_attn(x, mask, index_pos)
x = attn + residual
residual = x
x = self.ffn_norm(x)
w1 = self.ffw1.matmul_t(x)
w3 = self.ffw3.matmul_t(x)
mlp = self.ffw2.matmul_t(candle.nn.silu(w1) * w3)
return mlp + residual
def forward_attn(self, x, mask, index_pos):
b_size, seq_len, n_embd = x.shape
q = self.attention_wq.matmul_t(x)
k = self.attention_wk.matmul_t(x)
v = self.attention_wv.matmul_t(x)
q = q.reshape((b_size, seq_len, self.n_head, self.head_dim)).transpose(1, 2)
k = k.reshape((b_size, seq_len, self.n_kv_head, self.head_dim)).transpose(1, 2)
v = v.reshape((b_size, seq_len, self.n_kv_head, self.head_dim)).transpose(1, 2)
q = self.apply_rotary_emb(q, index_pos)
k = self.apply_rotary_emb(k, index_pos)
if self.kv_cache is not None and index_pos > 0:
prev_k, prev_v = self.kv_cache
k = candle.cat([prev_k, k], 2).contiguous()
v = candle.cat([prev_v, v], 2).contiguous()
self.kv_cache = (k, v)
# TODO: maybe repeat k/v here if we start supporting MQA.
att = q.matmul(k.t()) / self.head_dim**0.5
mask = mask.broadcast_as(att.shape)
att = masked_fill(att, mask, float("-inf"))
att = candle.nn.softmax(att, -1)
y = att.matmul(v.contiguous())
y = y.transpose(1, 2).reshape((b_size, seq_len, n_embd))
return self.attention_wo.matmul_t(y)
def apply_rotary_emb(self, x, index_pos):
(b_size, n_head, seq_len, n_embd) = x.shape
cos = self.cos.narrow(0, index_pos, seq_len).reshape((seq_len, n_embd//2, 1))
sin = self.sin.narrow(0, index_pos, seq_len).reshape((seq_len, n_embd//2, 1))
x = x.reshape((b_size, n_head, seq_len, n_embd//2, 2))
x0 = x.narrow(-1, 0, 1)
x1 = x.narrow(-1, 1, 1)
y0 = x0.broadcast_mul(cos) - x1.broadcast_mul(sin)
y1 = x0.broadcast_mul(sin) + x1.broadcast_mul(cos)
rope = candle.cat([y0, y1], -1)
return rope.flatten_from(-2)
def precompute_freqs_cis(hparams, freq_base):
head_dim = hparams["n_embd"] // hparams["n_head"]
theta = [1.0 / freq_base ** (i / head_dim) for i in range(0, head_dim, 2)]
theta = candle.tensor(theta)
idx_theta = [float(i) for i in range(MAX_SEQ_LEN)]
idx_theta = candle.tensor(idx_theta).reshape((MAX_SEQ_LEN, 1))
m = idx_theta.matmul(theta.unsqueeze(0))
return (m.cos(), m.sin())
class QuantizedLlama:
def __init__(self, hparams, all_tensors):
self.tok_embeddings = all_tensors["tok_embeddings.weight"].dequantize()
self.norm = RmsNorm(all_tensors["norm.weight"])
self.output = all_tensors["output.weight"]
self.layers = []
rope_freq = hparams.get("rope_freq", 10000.)
cos_sin = precompute_freqs_cis(hparams, rope_freq)
for layer_idx in range(hparams["n_layer"]):
layer = QuantizedLayer(layer_idx, hparams, all_tensors, cos_sin)
self.layers.append(layer)
def __call__(self, token, index_pos):
b_size, seq_len = token.shape
vocab_size, hidden_size = self.tok_embeddings.shape
token = token.reshape((b_size * seq_len,))
x = self.tok_embeddings.index_select(token, 0)
x = x.reshape((b_size, seq_len, hidden_size))
mask = [int(j > i) for j in range(seq_len) for i in range(seq_len)]
mask = candle.tensor(mask).reshape((seq_len, seq_len))
for layer in self.layers:
x = layer(x, mask, index_pos)
x = self.norm(x)
x = x.narrow(1, -1, 1).squeeze(1)
x = self.output.matmul_t(x)
return x
def gguf_rename(tensor_name):
if tensor_name == 'token_embd.weight': return 'tok_embeddings.weight'
if tensor_name == 'output_norm.weight': return 'norm.weight'
tensor_name = tensor_name.replace('blk.', 'layers.')
tensor_name = tensor_name.replace('.attn_q.', '.attention.wq.')
tensor_name = tensor_name.replace('.attn_k.', '.attention.wk.')
tensor_name = tensor_name.replace('.attn_v.', '.attention.wv.')
tensor_name = tensor_name.replace('.attn_output.', '.attention.wo.')
tensor_name = tensor_name.replace('.ffn_gate.', '.feed_forward.w1.')
tensor_name = tensor_name.replace('.ffn_down.', '.feed_forward.w2.')
tensor_name = tensor_name.replace('.ffn_up.', '.feed_forward.w3.')
tensor_name = tensor_name.replace('.attn_norm.', '.attention_norm.')
return tensor_name
def main():
if len(sys.argv) < 2:
raise ValueError("missing weight file argument")
filename = sys.argv[1]
print(f"reading model file {filename}")
if filename.endswith("gguf"):
all_tensors, metadata = candle.load_gguf(sys.argv[1])
vocab = metadata["tokenizer.ggml.tokens"]
for i, v in enumerate(vocab):
vocab[i] = '\n' if v == '<0x0A>' else v.replace('▁', ' ')
hparams = {k: v for (k, v) in metadata.items() if not k.startswith("tokenizer")}
print(hparams)
hparams = {
'n_vocab': len(vocab),
'n_embd': metadata['llama.embedding_length'],
'n_mult': 256,
'n_head': metadata['llama.attention.head_count'],
'n_head_kv': metadata['llama.attention.head_count_kv'],
'n_layer': metadata['llama.block_count'],
'n_rot': metadata['llama.rope.dimension_count'],
'rope_freq': metadata['llama.rope.freq_base'],
'ftype': metadata['general.file_type'],
}
all_tensors = { gguf_rename(k): v for k, v in all_tensors.items() }
else:
all_tensors, hparams, vocab = candle.load_ggml(sys.argv[1])
print(hparams)
model = QuantizedLlama(hparams, all_tensors)
print("model built, starting inference")
tokens = [1]
for token_idx in range(500):
last_token = tokens[-1]
lt = candle.tensor([last_token]).unsqueeze(0)
logits = model(lt, len(tokens))
# Greedy sampling for now
# pr = candle.nn.softmax(logits, -1)
m = logits.get(0).argmax_keepdim(-1)
next_token = m.values()[0]
print(vocab[next_token], end='', flush=True)
tokens.append(next_token)
if __name__ == '__main__':
main()
| candle-main | candle-pyo3/quant-llama.py |
import candle
t = candle.Tensor(42.0)
print(t)
print(t.shape, t.rank, t.device)
print(t + t)
t = candle.Tensor([3.0, 1, 4, 1, 5, 9, 2, 6])
print(t)
print(t+t)
t = t.reshape([2, 4])
print(t.matmul(t.t()))
print(t.to_dtype(candle.u8))
print(t.to_dtype("u8"))
t = candle.randn((5, 3))
print(t)
print(t.dtype)
t = candle.randn((16, 256))
quant_t = t.quantize("q6k")
dequant_t = quant_t.dequantize()
diff2 = (t - dequant_t).sqr()
print(diff2.mean_all())
| candle-main | candle-pyo3/test.py |
def remove_prefix(text, prefix):
return text[text.startswith(prefix) and len(prefix):]
nps = {}
for k, v in model.state_dict().items():
k = remove_prefix(k, 'module_list.')
nps[k] = v.detach().numpy()
np.savez('yolo-v3.ot', **nps)
| candle-main | candle-examples/examples/yolo-v3/extract-weights.py |
# Get the checkpoint from
# https://openaipublic.azureedge.net/main/whisper/models/d3dd57d32accea0b295c96e26691aa14d8822fac7d9d27d5dc00b4ca2826dd03/tiny.en.pt
import torch
from safetensors.torch import save_file
data = torch.load("tiny.en.pt")
weights = {}
for k, v in data["model_state_dict"].items():
weights[k] = v.contiguous()
print(k, v.shape, v.dtype)
save_file(weights, "tiny.en.safetensors")
print(data["dims"])
| candle-main | candle-examples/examples/whisper/extract_weights.py |
from enum import Enum
from typing import Callable
from unittest.mock import MagicMock
import pandas as pd
import pytest
from datasets import Dataset
from data_measurements.measurements import (
LabelDistribution,
LabelDistributionResults,
TextDuplicates,
TextDuplicatesResults,
TextLengths,
TextLengthsResults,
)
def pytest_collection_modifyitems(items):
for item in items:
if "end_to_end" in item.nodeid:
item.add_marker(pytest.mark.slow)
item.add_marker(pytest.mark.end_to_end)
@pytest.fixture
def dummy_tokenizer():
def tokenize(sentence: str):
return sentence.split()
return tokenize
@pytest.fixture
def mock_load_metric(monkeypatch):
load_metric = MagicMock()
monkeypatch.setattr("data_measurements.measurements.base.load_metric", load_metric)
return load_metric
@pytest.fixture
def mock_load_dataset(monkeypatch):
load_dataset = MagicMock()
monkeypatch.setattr(
"data_measurements.measurement_suite.load_dataset", load_dataset
)
return load_dataset
class MockMeasureMixin:
measure: Callable
name: str
def __new__(cls, *args, **kwargs):
mock = MagicMock(spec=cls)
mock.measure = lambda dataset: cls.measure(self=mock, dataset=dataset)
mock.name = cls.name
mock.feature = kwargs["feature"]
return mock
@pytest.fixture()
def mock_measurements():
mock_results = [
TextDuplicatesResults(duplicate_fraction=0.25),
TextLengthsResults(
average_instance_length=2.25,
standard_dev_instance_length=0.5,
num_instance_lengths=2,
lengths=pd.DataFrame(),
),
LabelDistributionResults(
label_distribution={"labels": [1, 0, 2], "fractions": [0.1, 0.6, 0.3]},
label_skew=0.5,
),
]
class MockedTextDuplicates(MockMeasureMixin, TextDuplicates):
def measure(self, dataset: Dataset):
return mock_results[0]
class MockedTextLengths(MockMeasureMixin, TextLengths):
def measure(self, dataset: Dataset):
return mock_results[1]
class MockedLabelDistribution(MockMeasureMixin, LabelDistribution):
def measure(self, dataset: Dataset):
return mock_results[2]
class Measurements(Enum):
TextDuplicates = MockedTextDuplicates
TextLengths = MockedTextLengths
LabelDistribution = MockedLabelDistribution
return Measurements, mock_results
| data-measurements-main | conftest.py |
# Lint as: python3
""" HuggingFace/Data-Measurements is an open library for measuring datasets.
Note:
VERSION needs to be formatted following the MAJOR.MINOR.PATCH convention
Simple check list for release from AllenNLP repo: https://github.com/allenai/allennlp/blob/master/setup.py
To create the package for pypi.
0. Prerequisites:
- Dependencies:
- twine: "pip install twine"
- Create an account in (and join the 'disaggregators' project):
- PyPI: https://pypi.org/
- Test PyPI: https://test.pypi.org/
1. Change the version in:
- __init__.py
- setup.py
2. Commit these changes: "git commit -m 'Release: VERSION'"
3. Add a tag in git to mark the release: "git tag VERSION -m 'Add tag VERSION for pypi'"
Push the tag to remote: git push --tags origin main
4. Build both the sources and the wheel. Do not change anything in setup.py between
creating the wheel and the source distribution (obviously).
First, delete any "build" directory that may exist from previous builds.
For the wheel, run: "python setup.py bdist_wheel" in the top level directory.
(this will build a wheel for the python version you use to build it).
For the sources, run: "python setup.py sdist"
You should now have a /dist directory with both .whl and .tar.gz source versions.
5. Check that everything looks correct by uploading the package to the pypi test server:
twine upload dist/* -r pypitest --repository-url=https://test.pypi.org/legacy/
Check that you can install it in a virtualenv/notebook by running:
pip install -i https://testpypi.python.org/pypi disaggregators
6. Upload the final version to actual pypi:
twine upload dist/* -r pypi
7. Fill release notes in the tag in GitHub once everything is looking hunky-dory.
8. Change the version in __init__.py and setup.py to X.X.X+1.dev0 (e.g. VERSION=1.18.3 -> 1.18.4.dev0).
Then push the change with a message 'set dev version'
"""
from setuptools import find_packages, setup
REQUIRED_PKGS = [
# Utilities from PyPA to e.g., compare versions
"packaging",
"pytest",
"datasets",
"evaluate",
"gradio",
"scipy",
"matplotlib",
"seaborn",
"plotly",
"numpy",
"scikit-learn",
"nltk"
]
TESTS_REQUIRE = [
# test dependencies
"pytest",
"nox",
]
QUALITY_REQUIRE = ["black~=22.0", "flake8>=3.8.3", "isort>=5.0.0", "pyyaml>=5.3.1"]
EXTRAS_REQUIRE = {
"dev": TESTS_REQUIRE + QUALITY_REQUIRE,
"tests": TESTS_REQUIRE,
"quality": QUALITY_REQUIRE,
}
setup(
name="data-measurements",
version="0.1.0.dev0", # expected format is one of x.y.z.dev0, or x.y.z.rc1 or x.y.z (no to dashes, yes to dots)
description="HuggingFace community-driven open-source library for dataset measurement",
long_description=open("README.md", encoding="utf-8").read(),
long_description_content_type="text/markdown",
author="HuggingFace Inc.",
author_email="[email protected]",
url="https://github.com/HuggingFace/data-measurements",
download_url="https://github.com/HuggingFace/data-measurements/tags",
license="Apache 2.0",
package_dir={"": "src"},
packages=find_packages("src"),
install_requires=REQUIRED_PKGS,
extras_require=EXTRAS_REQUIRE,
python_requires=">=3.7.0",
classifiers=[
"Development Status :: 1 - Planning",
"Intended Audience :: Developers",
"Intended Audience :: Education",
"Intended Audience :: Science/Research",
"License :: OSI Approved :: Apache Software License",
"Operating System :: OS Independent",
"Programming Language :: Python :: 3",
"Programming Language :: Python :: 3.8",
"Programming Language :: Python :: 3.9",
"Programming Language :: Python :: 3.10",
"Topic :: Scientific/Engineering :: Artificial Intelligence",
],
keywords="machine learning dataset measurement",
zip_safe=False, # Required for mypy to find the py.typed file
)
| data-measurements-main | setup.py |
import nox
python_versions = ["3.8", "3.9", "3.10"]
@nox.session(python=python_versions)
def tests(session):
session.install(".[tests]")
session.run("make", "test", external=True)
| data-measurements-main | noxfile.py |
import pytest
from data_measurements import DataMeasurementSuite
@pytest.fixture
def measurements(mock_measurements):
mock_measurements, _ = mock_measurements
return [
mock_measurements.TextDuplicates.value,
mock_measurements.TextLengths.value,
mock_measurements.LabelDistribution.value,
]
@pytest.fixture
def expected_results(mock_measurements):
_, mock_results = mock_measurements
return mock_results
@pytest.fixture
def suite(measurements, mock_load_dataset, mock_load_metric, monkeypatch):
return DataMeasurementSuite(
dataset="imdb",
measurements=measurements,
feature="text",
label="label",
split="train",
tokenizer=lambda x: x,
)
def test_measurement_suite_initialize(suite, mock_load_dataset, measurements, monkeypatch):
mock_load_dataset.assert_called_with("imdb", split="train")
assert len(suite.measurements) == len(measurements)
def test_measurement_suite_run(suite, measurements, expected_results, monkeypatch):
assert suite.measurements[0].feature == "text"
assert suite.measurements[1].feature == "text"
assert suite.measurements[2].feature == "label"
results = suite.run()
assert results["text_duplicates"] == expected_results[0]
assert results["text_lengths"] == expected_results[1]
assert results["label_distribution"] == expected_results[2]
| data-measurements-main | tests/test_measurement_suite.py |
import pandas as pd
from data_measurements import DataMeasurementSuite
from data_measurements.measurements import (
LabelDistribution,
LabelDistributionResults,
TextDuplicates,
TextDuplicatesResults,
TextLengths,
TextLengthsResults,
)
def test_end_to_end(dummy_tokenizer):
# TODO: Some datasets for end2end testing: hate_speech18, wiki_qa (has a funky format), c4 (timing tests for the first CHUNK of it (250k lines)) –see _DATASET_LIST and _STREAMABLE_DATASET_LIST...
suite = DataMeasurementSuite(
dataset="society-ethics/data-measurements-end-to-end-test",
feature="text",
label="label",
split="train",
tokenizer=dummy_tokenizer,
measurements=[
TextDuplicates,
TextLengths,
LabelDistribution,
],
)
results = suite.run()
assert results["text_duplicates"] == TextDuplicatesResults(duplicate_fraction=0.25)
assert results["text_lengths"] == TextLengthsResults(
average_instance_length=2.25,
standard_dev_instance_length=0.5,
num_instance_lengths=2,
lengths=pd.DataFrame([2, 3, 2, 2])[0],
)
assert results["label_distribution"] == LabelDistributionResults(
label_distribution={"labels": [1, 2], "fractions": [0.75, 0.25]},
label_skew=1.1547005383792515,
)
| data-measurements-main | tests/test_end_to_end.py |
import pytest
from datasets import Dataset
from data_measurements.measurements import Cooccurences
@pytest.fixture
def dataset():
return Dataset.from_list(
[
{"text": "he went to the park"},
{"text": "she has a cat"},
{"text": "their car is blue"},
]
)
def test_cooccurences_initialize(dummy_tokenizer):
Cooccurences(tokenizer=dummy_tokenizer, feature=None)
def test_cooccurences_run(dummy_tokenizer, dataset):
cooccurences = Cooccurences(tokenizer=dummy_tokenizer, feature="text")
cooccurences.measure(dataset)
| data-measurements-main | tests/measurements/test_cooccurences.py |
from datasets import Dataset
from data_measurements.measurements import TextDuplicates
def test_text_duplicates_initialize(mock_load_metric):
TextDuplicates(feature=None)
mock_load_metric.assert_called_once_with("text_duplicates")
def test_text_duplicates_run(mock_load_metric):
dataset = Dataset.from_dict({"text": ["Hello", "World", "Hello", "Foo Bar"]})
text_duplicates = TextDuplicates(feature="text")
text_duplicates.measure(dataset)
text_duplicates.metric.compute.assert_called_once_with(data=dataset["text"])
| data-measurements-main | tests/measurements/test_text_duplicates.py |
from datasets import Dataset
from data_measurements.measurements import LabelDistribution
def test_label_distribution_initialize(mock_load_metric):
LabelDistribution(feature="text")
mock_load_metric.assert_called_once_with("label_distribution")
def test_label_distribution_run(mock_load_metric):
dataset = Dataset.from_dict(
{
"text": ["Hello", "World", "Hello", "Foo Bar"],
"label": [1, 2, 1, 1],
}
)
label_distribution = LabelDistribution(feature="label")
label_distribution.measure(dataset)
label_distribution.metric.compute.assert_called_once_with(data=dataset["label"])
def test_label_distribution_figure(mock_load_metric):
dataset = Dataset.from_dict(
{
"text": ["Hello", "World", "Hello", "Foo Bar"],
"label": [1, 2, 1, 1],
}
)
# TODO: Some kind of assertion?
label_distribution = LabelDistribution(feature="label")
results = label_distribution.measure(dataset)
results.to_figure()
| data-measurements-main | tests/measurements/test_label_distribution.py |
import pytest
from datasets import Dataset
from data_measurements.measurements import PMI
@pytest.fixture
def dataset():
return Dataset.from_list(
[
{"text": "he went to the park"},
{"text": "she has a cat"},
{"text": "their car is blue"},
]
)
def test_pmi_initialize(dummy_tokenizer):
PMI(tokenizer=dummy_tokenizer, feature=None)
def test_pmi_run(dummy_tokenizer, dataset):
pmi = PMI(tokenizer=dummy_tokenizer, feature="text")
pmi.measure(dataset)
| data-measurements-main | tests/measurements/test_pmi.py |
from statistics import mean, stdev
from unittest.mock import MagicMock
import pytest
from datasets import Dataset
from data_measurements.measurements import TextLengths
@pytest.fixture
def mock_statistics(monkeypatch):
mock_mean = MagicMock()
mock_mean.return_value = "mean"
mock_stdev = MagicMock()
mock_stdev.return_value = "stdev"
monkeypatch.setattr("data_measurements.measurements.text_lengths.mean", mock_mean)
monkeypatch.setattr("data_measurements.measurements.text_lengths.stdev", mock_stdev)
return {"mean": mock_mean, "stdev": mock_stdev}
@pytest.fixture
def dataset():
return Dataset.from_list(
[
{"text": "Hello world"},
{"text": "What is up"},
{"text": "Kitty Cat"},
]
)
def test_text_lengths_initialize(dummy_tokenizer):
TextLengths(tokenizer=dummy_tokenizer, feature=None)
def test_text_lengths_run_mock_stats(mock_statistics, dummy_tokenizer, dataset):
text_lengths = TextLengths(tokenizer=dummy_tokenizer, feature="text")
results = text_lengths.measure(dataset)
assert results.average_instance_length == "mean"
assert results.standard_dev_instance_length == "stdev"
assert results.num_instance_lengths == 2
mock_statistics["mean"].assert_called_once()
mock_statistics["stdev"].assert_called_once()
def test_text_lengths_run(dataset, dummy_tokenizer):
text_lengths = TextLengths(tokenizer=dummy_tokenizer, feature="text")
results = text_lengths.measure(dataset)
assert results.average_instance_length == mean([2, 3, 2])
assert results.standard_dev_instance_length == stdev([2, 3, 2])
assert results.num_instance_lengths == 2
def test_text_lengths_figure(dataset, dummy_tokenizer):
# TODO: Some kind of assertion?
text_lengths = TextLengths(tokenizer=dummy_tokenizer, feature="text")
results = text_lengths.measure(dataset)
results.to_figure()
| data-measurements-main | tests/measurements/test_text_lengths.py |
# Copyright 2021 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import argparse
import ast
import gradio as gr
import utils
from data_measurements import DataMeasurementSuite
from data_measurements.measurements import (
GeneralStats,
LabelDistribution,
TextLengths,
TextDuplicates,
)
logs = utils.prepare_logging(__file__)
def get_suite():
def dummy_tokenizer(sentence: str):
return sentence.split()
suite = DataMeasurementSuite(
dataset="society-ethics/data-measurements-end-to-end-test",
feature="text",
label="label",
split="train",
tokenizer=dummy_tokenizer,
measurements=[
GeneralStats,
LabelDistribution,
TextLengths,
TextDuplicates,
],
)
return suite
# def get_ui_widgets():
# """Get the widgets that will be displayed in the UI."""
# return [
# # widgets.DatasetDescription(DATASET_NAME_TO_DICT),
# # widgets.Npmi(),
# # widgets.Zipf()
# ]
def get_title(dstats):
title_str = f"### Showing: {dstats.dset_name} - {dstats.dset_config} - {dstats.split_name} - {'-'.join(dstats.text_field)}"
logs.info("showing header")
return title_str
suite = get_suite()
# TODO: I want to run this somewhere smart, I guess? But here is fine for now.
results = suite.run()
def create_demo():
with gr.Blocks() as demo:
state = gr.State()
with gr.Row():
with gr.Column(scale=1):
widget_list = [w() for w in suite.widgets]
with gr.Column(scale=4):
gr.Markdown("# Data Measurements Tool")
title = gr.Markdown()
for widget in widget_list:
widget.render()
def update_ui():
output = {
title: "Temp Title",
state: {} # TODO: Do we even need to store the state as a Gradio object? I don't think so..
}
for widget, result in zip(widget_list, results.values()):
output.update(widget.update(result))
return output
measurements = [comp for output in widget_list for comp in output.output_components]
demo.load(
update_ui,
inputs=[
# TODO
# dataset_args["dset_name"],
# dataset_args["dset_config"],
# dataset_args["split_name"],
# dataset_args["text_field"]
],
outputs=[title, state] + measurements
)
return demo
if __name__ == "__main__":
create_demo().launch()
# TODO: TEMPORARY
demo = create_demo()
demo.launch()
| data-measurements-main | src/app.py |
import logging
import os
from pathlib import Path
def prepare_logging(fid):
# Create the directory for log files (if it doesn't exist)
Path('./log_files').mkdir(exist_ok=True)
log_fid = Path(fid).stem
logs = logging.getLogger(log_fid)
logs.setLevel(logging.DEBUG)
logs.propagate = False
log_fid = Path(fid).stem
if not logs.handlers:
# Logging info to log file
file_path = ("./log_files/%s.log" % log_fid)
print("Logging output in %s " % file_path)
file = logging.FileHandler(file_path)
fileformat = logging.Formatter("%(asctime)s:%(pathname)s, %(module)s:%(lineno)s\n%(message)s")
file.setLevel(logging.INFO)
file.setFormatter(fileformat)
# Logging debug messages to stream
stream = logging.StreamHandler()
streamformat = logging.Formatter("[data_measurements_tool] {%(pathname)s:%(lineno)d} %(module)s %(levelname)s - %(message)s")
stream.setLevel(logging.DEBUG)
stream.setFormatter(streamformat)
logs.addHandler(file)
logs.addHandler(stream)
return logs | data-measurements-main | src/utils/__init__.py |
# Copyright 2021 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import json
import os
import pandas as pd
import plotly
import pyarrow.feather as feather
import utils
from dataclasses import asdict
from datasets import Dataset, get_dataset_infos, load_dataset, load_from_disk, \
NamedSplit
from dotenv import load_dotenv
from huggingface_hub import Repository, list_datasets
from json2html import *
from os import getenv
from os.path import exists, isdir, join as pjoin
from pathlib import Path
# treating inf values as NaN as well
pd.set_option("use_inf_as_na", True)
## String names used in Hugging Face dataset configs.
HF_FEATURE_FIELD = "features"
HF_LABEL_FIELD = "label"
HF_DESC_FIELD = "description"
CACHE_DIR = "cache_dir"
## String names we are using within this code.
# These are not coming from the stored dataset nor HF config,
# but rather used as identifiers in our dicts and dataframes.
TEXT_FIELD = "text"
PERPLEXITY_FIELD = "perplexity"
TOKENIZED_FIELD = "tokenized_text"
EMBEDDING_FIELD = "embedding"
LENGTH_FIELD = "length"
VOCAB = "vocab"
WORD = "word"
CNT = "count"
PROP = "proportion"
TEXT_NAN_CNT = "text_nan_count"
TXT_LEN = "text lengths"
TOT_WORDS = "total words"
TOT_OPEN_WORDS = "total open words"
_DATASET_LIST = [
"c4",
"squad",
"squad_v2",
"hate_speech18",
"hate_speech_offensive",
"glue",
"super_glue",
"wikitext",
"imdb",
]
_STREAMABLE_DATASET_LIST = [
"c4",
"wikitext",
]
_MAX_ROWS = 200000
logs = utils.prepare_logging(__file__)
def _load_dotenv_for_cache_on_hub():
"""
This function loads and returns the organization name that you've set up on the
hub for storing your data measurements cache on the hub. It also loads the associated
access token. It expects you to have HUB_CACHE_ORGANIZATION=<the organization you've set up on the hub to store your cache>
and HF_TOKEN=<your hf token> on separate lines in a file named .env at the root of this repo.
Returns:
tuple of strings: hub_cache_organization, hf_token
"""
if Path(".env").is_file():
load_dotenv(".env")
hf_token = getenv("HF_TOKEN")
hub_cache_organization = getenv("HUB_CACHE_ORGANIZATION")
return hub_cache_organization, hf_token
def get_cache_dir_naming(out_dir, dataset, config, split, feature):
feature_text = hyphenated(feature)
dataset_cache_name = f"{dataset}_{config}_{split}_{feature_text}"
local_dataset_cache_dir = out_dir + "/" + dataset_cache_name
return dataset_cache_name, local_dataset_cache_dir
def initialize_cache_hub_repo(local_cache_dir, dataset_cache_name):
"""
This function tries to initialize a dataset cache on the huggingface hub. The
function expects you to have HUB_CACHE_ORGANIZATION=<the organization you've set up on the hub to store your cache>
and HF_TOKEN=<your hf token> on separate lines in a file named .env at the root of this repo.
Args:
local_cache_dir (string):
The path to the local dataset cache.
dataset_cache_name (string):
The name of the dataset repo on the huggingface hub that you want.
"""
hub_cache_organization, hf_token = _load_dotenv_for_cache_on_hub()
clone_source = pjoin(hub_cache_organization, dataset_cache_name)
repo = Repository(local_dir=local_cache_dir,
clone_from=clone_source,
repo_type="dataset", use_auth_token=hf_token)
repo.lfs_track(["*.feather"])
return repo
def pull_cache_from_hub(cache_path, dataset_cache_dir):
"""
This function tries to pull a datasets cache from the huggingface hub if a
cache for the dataset does not already exist locally. The function expects you
to have you HUB_CACHE_ORGANIZATION=<the organization you've set up on the hub to store your cache>
and HF_TOKEN=<your hf token> on separate lines in a file named .env at the root of this repo.
Args:
cache_path (string):
The path to the local dataset cache that you want.
dataset_cache_dir (string):
The name of the dataset repo on the huggingface hub.
"""
hub_cache_organization, hf_token = _load_dotenv_for_cache_on_hub()
clone_source = pjoin(hub_cache_organization, dataset_cache_dir)
if isdir(cache_path):
logs.warning("Already a local cache for the dataset, so not pulling from the hub.")
else:
# Here, dataset_info.id is of the form: <hub cache organization>/<dataset cache dir>
if dataset_cache_dir in [
dataset_info.id.split("/")[-1] for dataset_info in
list_datasets(author=hub_cache_organization,
use_auth_token=hf_token)]:
Repository(local_dir=cache_path,
clone_from=clone_source,
repo_type="dataset", use_auth_token=hf_token)
logs.info("Pulled cache from hub!")
else:
logs.warning("Asking to pull cache from hub but cannot find cached repo on the hub.")
def load_truncated_dataset(
dataset_name,
config_name,
split_name,
num_rows=_MAX_ROWS,
use_cache=True,
cache_dir=CACHE_DIR,
use_streaming=True,
save=True,
):
"""
This function loads the first `num_rows` items of a dataset for a
given `config_name` and `split_name`.
If `use_cache` and `cache_name` exists, the truncated dataset is loaded from
`cache_name`.
Otherwise, a new truncated dataset is created and immediately saved
to `cache_name`.
When the dataset is streamable, we iterate through the first
`num_rows` examples in streaming mode, write them to a jsonl file,
then create a new dataset from the json.
This is the most direct way to make a Dataset from an IterableDataset
as of datasets version 1.6.1.
Otherwise, we download the full dataset and select the first
`num_rows` items
Args:
dataset_name (string):
dataset id in the dataset library
config_name (string):
dataset configuration
split_name (string):
split name
num_rows (int) [optional]:
number of rows to truncate the dataset to
cache_dir (string):
name of the cache directory
use_cache (bool):
whether to load from the cache if it exists
use_streaming (bool):
whether to use streaming when the dataset supports it
save (bool):
whether to save the dataset locally
Returns:
Dataset: the (truncated if specified) dataset as a Dataset object
"""
logs.info("Loading or preparing dataset saved in %s " % cache_dir)
if use_cache and exists(cache_dir):
dataset = load_from_disk(cache_dir)
else:
if use_streaming and dataset_name in _STREAMABLE_DATASET_LIST:
iterable_dataset = load_dataset(
dataset_name,
name=config_name,
split=split_name,
streaming=True,
).take(num_rows)
rows = list(iterable_dataset)
f = open("temp.jsonl", "w", encoding="utf-8")
for row in rows:
_ = f.write(json.dumps(row) + "\n")
f.close()
dataset = Dataset.from_json(
"temp.jsonl", features=iterable_dataset.features, split=NamedSplit(split_name)
)
else:
full_dataset = load_dataset(
dataset_name,
name=config_name,
split=split_name,
)
if len(full_dataset) >= num_rows:
dataset = full_dataset.select(range(num_rows))
# Make the directory name clear that it's not the full dataset.
cache_dir = pjoin(cache_dir, ("_%s" % num_rows))
else:
dataset = full_dataset
if save:
dataset.save_to_disk(cache_dir)
return dataset
def hyphenated(features):
"""When multiple features are asked for, hyphenate them together when they're used for filenames or titles"""
return '-'.join(features)
def get_typed_features(features, ftype="string", parents=None):
"""
Recursively get a list of all features of a certain dtype
:param features:
:param ftype:
:param parents:
:return: a list of tuples > e.g. ('A', 'B', 'C') for feature example['A']['B']['C']
"""
if parents is None:
parents = []
typed_features = []
for name, feat in features.items():
if isinstance(feat, dict):
if feat.get("dtype", None) == ftype or feat.get("feature", {}).get(
("dtype", None) == ftype
):
typed_features += [tuple(parents + [name])]
elif "feature" in feat:
if feat["feature"].get("dtype", None) == ftype:
typed_features += [tuple(parents + [name])]
elif isinstance(feat["feature"], dict):
typed_features += get_typed_features(
feat["feature"], ftype, parents + [name]
)
else:
for k, v in feat.items():
if isinstance(v, dict):
typed_features += get_typed_features(
v, ftype, parents + [name, k]
)
elif name == "dtype" and feat == ftype:
typed_features += [tuple(parents)]
return typed_features
def get_label_features(features, parents=None):
"""
Recursively get a list of all features that are ClassLabels
:param features:
:param parents:
:return: pairs of tuples as above and the list of class names
"""
if parents is None:
parents = []
label_features = []
for name, feat in features.items():
if isinstance(feat, dict):
if "names" in feat:
label_features += [(tuple(parents + [name]), feat["names"])]
elif "feature" in feat:
if "names" in feat:
label_features += [
(tuple(parents + [name]), feat["feature"]["names"])
]
elif isinstance(feat["feature"], dict):
label_features += get_label_features(
feat["feature"], parents + [name]
)
else:
for k, v in feat.items():
if isinstance(v, dict):
label_features += get_label_features(v, parents + [name, k])
elif name == "names":
label_features += [(tuple(parents), feat)]
return label_features
# get the info we need for the app sidebar in dict format
def dictionarize_info(dset_info):
info_dict = asdict(dset_info)
res = {
"config_name": info_dict["config_name"],
"splits": {
spl: spl_info["num_examples"]
for spl, spl_info in info_dict["splits"].items()
},
"features": {
"string": get_typed_features(info_dict["features"], "string"),
"int32": get_typed_features(info_dict["features"], "int32"),
"float32": get_typed_features(info_dict["features"], "float32"),
"label": get_label_features(info_dict["features"]),
},
"description": dset_info.description,
}
return res
def get_dataset_info_dicts(dataset_id=None):
"""
Creates a dict from dataset configs.
Uses the datasets lib's get_dataset_infos
:return: Dictionary mapping dataset names to their configurations
"""
if dataset_id is not None:
ds_name_to_conf_dict = {
dataset_id: {
config_name: dictionarize_info(config_info)
for config_name, config_info in get_dataset_infos(dataset_id).items()
}
}
else:
ds_name_to_conf_dict = {
ds_id: {
config_name: dictionarize_info(config_info)
for config_name, config_info in get_dataset_infos(ds_id).items()
}
for ds_id in _DATASET_LIST
}
return ds_name_to_conf_dict
# get all instances of a specific field in a dataset
def extract_field(examples, field_path, new_field_name=None):
if new_field_name is None:
new_field_name = "_".join(field_path)
field_list = []
# TODO: Breaks the CLI if this isn't checked.
if isinstance(field_path, str):
field_path = [field_path]
item_list = examples[field_path[0]]
for field_name in field_path[1:]:
item_list = [
next_item
for item in item_list
for next_item in (
item[field_name]
if isinstance(item[field_name], list)
else [item[field_name]]
)
]
field_list += [
field
for item in item_list
for field in (item if isinstance(item, list) else [item])
]
return {new_field_name: field_list}
def make_path(path):
os.makedirs(path, exist_ok=True)
def counter_dict_to_df(dict_input, key_as_column=False):
df_output = pd.DataFrame(dict_input, index=[0]).T
if key_as_column:
df_output.reset_index(inplace=True)
df_output.columns = ["instance", "count"]
else:
df_output.columns = ["count"]
return df_output.sort_values(by="count", ascending=False)
def write_plotly(fig, fid):
write_json(plotly.io.to_json(fig), fid)
def read_plotly(fid):
fig = plotly.io.from_json(json.load(open(fid, encoding="utf-8")))
return fig
def write_json_as_html(input_json, html_fid):
html_dict = json2html.convert(json=input_json)
with open(html_fid, "w+") as f:
f.write(html_dict)
def df_to_write_html(input_df, html_fid):
"""Writes a dataframe to an HTML file"""
input_df.to_HTML(html_fid)
def read_df(df_fid):
return pd.DataFrame.from_dict(read_json(df_fid), orient="index")
def write_df(df, df_fid):
"""In order to preserve the index of our dataframes, we can't
use the compressed pandas dataframe file format .feather.
There's a preference for json amongst HF devs, so we use that here."""
df_dict = df.to_dict('index')
write_json(df_dict, df_fid)
def write_json(json_dict, json_fid):
with open(json_fid, "w", encoding="utf-8") as f:
json.dump(json_dict, f)
def read_json(json_fid):
json_dict = json.load(open(json_fid, encoding="utf-8"))
return json_dict | data-measurements-main | src/utils/dataset_utils.py |
# Copyright 2021 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import gradio as gr
import numpy as np
import pandas as pd
from matplotlib.figure import Figure
import seaborn as sns
import statistics
# TODO: Temporary (for WiFi reasons)
# import streamlit as st
import utils
import utils.dataset_utils as ds_utils
# from st_aggrid import AgGrid, GridOptionsBuilder
from utils.dataset_utils import HF_DESC_FIELD, HF_FEATURE_FIELD, HF_LABEL_FIELD
logs = utils.prepare_logging(__file__)
# TODO: Toggled off for WiFi reasons
# st.set_option('deprecation.showPyplotGlobalUse', False)
# Note: Make sure to consider colorblind-friendly colors for your images! Ex:
# ["#332288", "#117733", "#882255", "#AA4499", "#CC6677", "#44AA99", "#DDCC77",
# "#88CCEE"]
pd.options.display.float_format = "{:,.3f}".format # '{:20,.2f}'.format
def subheader():
gr.Markdown("""This demo showcases the
[dataset metrics as we develop them](https://huggingface.co/blog/data-measurements-tool).
Right now this has:
- dynamic loading of datasets in the lib
- fetching config and info without downloading the dataset
- propose the list of candidate text and label features to select.
""")
def get_label_names(dataset_name: str, config_name: str, ds_name_to_dict):
label_field, label_names = (
ds_name_to_dict[dataset_name][config_name][HF_FEATURE_FIELD][
HF_LABEL_FIELD][0]
if len(
ds_name_to_dict[dataset_name][config_name][HF_FEATURE_FIELD][
HF_LABEL_FIELD]
) > 0
else ((), [])
)
return label_field, label_names
def update_dataset(dataset_name: str, ds_name_to_dict):
# choose a config to analyze
ds_configs = ds_name_to_dict[dataset_name]
# special handling for the largest-by-far dataset, C4
if dataset_name == "c4":
config_names = ['en', 'en.noblocklist', 'realnewslike']
else:
config_names = list(ds_configs.keys())
config_name = config_names[0]
ds_config = ds_configs[config_name]
text_features = ds_config[HF_FEATURE_FIELD]["string"]
text_features = [('text',)] if dataset_name == "c4" else [tp for tp in text_features if tp[0] != "id"]
feature = str(text_features[0])
text_features = [str(f) for f in text_features]
avail_splits = list(ds_config["splits"].keys())
split = avail_splits[0]
return [(config_names, config_name), (text_features, feature), (avail_splits, split)]
def update_config(dataset_name: str, config_name: str, ds_name_to_dict):
ds_config = ds_name_to_dict[dataset_name][config_name]
text_features = ds_config[HF_FEATURE_FIELD]["string"]
text_features = [('text',)] if dataset_name == "c4" else [tp for tp in text_features if tp[0] != "id"]
feature = str(text_features[0])
text_features = [str(f) for f in text_features]
avail_splits = list(ds_config["splits"].keys())
split = avail_splits[0]
return [(text_features, feature), (avail_splits, split)]
def sidebar_selection(ds_name_to_dict, column_id=""):
ds_names = list(ds_name_to_dict.keys())
with gr.Accordion(f"Choose dataset and field {column_id}", open=True):
subheader()
# choose a dataset to analyze
ds_name = gr.Dropdown(
label=f"Choose dataset to explore{column_id}:",
choices=ds_names,
value="hate_speech18",
)
# choose a config to analyze
ds_configs = ds_name_to_dict[ds_name.value]
# special handling for the largest-by-far dataset, C4
if ds_name == "c4":
config_names = ['en', 'en.noblocklist', 'realnewslike']
else:
config_names = list(ds_configs.keys())
config_name = gr.Dropdown(
label=f"Choose configuration{column_id}:",
choices=config_names,
value=config_names[0],
)
# choose a subset of num_examples
ds_config = ds_configs[config_name.value]
text_features = ds_config[HF_FEATURE_FIELD]["string"]
# TODO @yacine: Explain what this is doing and why eg tp[0] could = "id"
text = f"Which text feature from the {column_id} dataset would you like to analyze?"
choices = [('text',)] if ds_name == "c4" else [tp for tp in text_features if tp[0] != "id"]
text_field = gr.Dropdown(
label=text,
choices=[str(f) for f in choices],
value=str(choices[0])
)
# Choose a split and dataset size
avail_splits = list(ds_config["splits"].keys())
# 12.Nov note: Removing "test" because those should not be examined
# without discussion of pros and cons, which we haven't done yet.
if "test" in avail_splits:
avail_splits.remove("test")
split = gr.Dropdown(
label=f"Which split from the{column_id} dataset would you like to analyze?",
choices=avail_splits,
value=avail_splits[0],
)
label_field, label_names = get_label_names(ds_name.value, config_name.value, ds_name_to_dict)
calculate_btn = gr.Button(value="Calculate", variant="primary")
return {
"dset_name": ds_name,
"dset_config": config_name,
"split_name": split,
"text_field": text_field,
"label_field": label_field,
"label_names": label_names,
"calculate_btn": calculate_btn
}
def expander_header(dstats, ds_name_to_dict, column_id=""):
with st.expander(f"Dataset Description{column_id}"):
st.markdown(
ds_name_to_dict[dstats.dset_name][dstats.dset_config][HF_DESC_FIELD]
)
st.dataframe(dstats.dset_peek)
def expander_general_stats(dstats, column_id=""):
with gr.Accordion(f"General Text Statistics{column_id}"):
st.caption(
"Use this widget to check whether the terms you see most "
"represented in the dataset make sense for the goals of the dataset."
)
st.markdown("There are {0} total words".format(str(dstats.total_words)))
st.markdown(
"There are {0} words after removing closed "
"class words".format(str(dstats.total_open_words))
)
st.markdown(
"The most common "
"[open class words](https://dictionary.apa.org/open-class-words) "
"and their counts are: "
)
st.dataframe(dstats.sorted_top_vocab_df)
st.markdown(
"There are {0} missing values in the dataset.".format(
str(dstats.text_nan_count)
)
)
if dstats.dups_frac > 0:
st.markdown(
"The dataset is {0}% duplicates. "
"For more information about the duplicates, "
"click the 'Duplicates' tab below.".format(
str(round(dstats.dups_frac * 100, 2)))
)
else:
st.markdown("There are 0 duplicate items in the dataset. ")
def expander_label_distribution(dstats, column_id=""):
with st.expander(f"Label Distribution{column_id}", expanded=False):
st.caption(
"Use this widget to see how balanced the labels in your dataset are."
)
if dstats.fig_labels:
st.plotly_chart(dstats.fig_labels, use_container_width=True)
else:
st.markdown("No labels were found in the dataset")
def expander_text_lengths(dstats, column_id=""):
_TEXT_LENGTH_CAPTION = (
"Use this widget to identify outliers, particularly suspiciously long "
"outliers."
)
with st.expander(f"Text Lengths{column_id}", expanded=False):
st.caption(_TEXT_LENGTH_CAPTION)
st.markdown(
"Below, you can see how the lengths of the text instances in your "
"dataset are distributed."
)
st.markdown(
"Any unexpected peaks or valleys in the distribution may help to "
"identify instances you want to remove or augment."
)
st.markdown(
"### Here is the count of different text lengths in "
"your dataset:"
)
# When matplotlib first creates this, it's a Figure.
# Once it's saved, then read back in,
# it's an ndarray that must be displayed using st.image
# (I know, lame).
if isinstance(dstats.length_obj.fig_lengths, Figure):
st.pyplot(dstats.length_obj.fig_lengths, use_container_width=True)
else:
try:
st.image(dstats.length_obj.fig_lengths)
except Exception as e:
logs.exception("Hit exception for lengths figure:")
logs.exception(e)
st.markdown(
"The average length of text instances is **"
+ str(round(dstats.length_obj.avg_length, 2))
+ " words**, with a standard deviation of **"
+ str(round(dstats.length_obj.std_length, 2))
+ "**."
)
if dstats.length_obj.lengths_df is not None:
start_id_show_lengths = st.selectbox(
"Show examples of length:",
np.sort(dstats.length_obj.lengths_df["length"].unique())[::-1].tolist(),
key=f"select_show_length_{column_id}",
)
st.table(
dstats.length_obj.lengths_df[
dstats.length_obj.lengths_df["length"] == start_id_show_lengths
].set_index("length")
)
def expander_text_duplicates(dstats, column_id=""):
with st.expander(f"Text Duplicates{column_id}", expanded=False):
st.caption(
"Use this widget to identify text strings that appear more than "
"once."
)
st.markdown(
"A model's training and testing may be negatively affected by "
"unwarranted duplicates "
"([Lee et al., 2021](https://arxiv.org/abs/2107.06499))."
)
st.markdown("------")
st.write(
"### Here is the list of all the duplicated items and their counts "
"in the dataset."
)
if not dstats.duplicates_results:
st.write("There are no duplicates in this dataset! 🥳")
else:
st.write("The fraction of the data that is a duplicate is:")
st.write(str(round(dstats.dups_frac, 4)))
# TODO: Check if this is slow when the size is large --
# Should we store as dataframes?
# Dataframes allow this to be interactive.
st.dataframe(ds_utils.counter_dict_to_df(dstats.dups_dict))
def expander_text_perplexities(dstats, column_id=""):
with st.expander(f"Text Perplexities{column_id}", expanded=False):
st.caption(
"Use this widget to identify text perplexities from GPT-2."
)
st.markdown(
"""
Outlier perplexities, especially very high values, could highlight
an issue with an example. Smaller variations should be interpreted
with more care, as they indicate how similar to the GPT-2 training
corpus the examples are rather than being reflective of general
linguistic properties.
For more information on GPT-2,
see its [model card](https://hf.co/gpt2).
"""
)
st.markdown("------")
st.write(
"### Here is the list of the examples in the dataset, sorted by "
"GPT-2 perplexity:"
)
if dstats.perplexities_df is None or dstats.perplexities_df.empty:
st.write(
"Perplexities have not been computed yet for this dataset, or "
"this dataset is too large for the UI (> 1,000,000 examples).")
else:
st.dataframe(dstats.perplexities_df.reset_index(drop=True))
def expander_npmi_description(min_vocab):
_NPMI_CAPTION = (
"Use this widget to identify problematic biases and stereotypes in "
"your data."
)
_NPMI_CAPTION1 = """
nPMI scores for a word help to identify potentially
problematic associations, ranked by how close the association is."""
_NPMI_CAPTION2 = """
nPMI bias scores for paired words help to identify how word
associations are skewed between the selected selected words
([Aka et al., 2021](https://arxiv.org/abs/2103.03417)).
"""
st.caption(_NPMI_CAPTION)
st.markdown(_NPMI_CAPTION1)
st.markdown(_NPMI_CAPTION2)
st.markdown(" ")
st.markdown(
"You can select from gender and sexual orientation "
"identity terms that appear in the dataset at least %s "
"times." % min_vocab
)
st.markdown(
"The resulting ranked words are those that co-occur with both "
"identity terms. "
)
st.markdown(
"The more *positive* the score, the more associated the word is with "
"the first identity term. "
"The more *negative* the score, the more associated the word is with "
"the second identity term."
)
def expander_zipf(dstats, column_id=""):
z = dstats.z
zipf_fig = dstats.zipf_fig
with st.expander(
f"Vocabulary Distribution{column_id}: Zipf's Law Fit", expanded=False
):
try:
_ZIPF_CAPTION = """This shows how close the observed language is to an ideal
natural language distribution following [Zipf's law](https://en.wikipedia.org/wiki/Zipf%27s_law),
calculated by minimizing the [Kolmogorov-Smirnov (KS) statistic](https://en.wikipedia.org/wiki/Kolmogorov%E2%80%93Smirnov_test)."""
powerlaw_eq = r"""p(x) \propto x^{- \alpha}"""
zipf_summary = (
"The optimal alpha based on this dataset is: **"
+ str(round(z.alpha, 2))
+ "**, with a KS distance of: **"
+ str(round(z.ks_distance, 2))
)
zipf_summary += (
"**. This was fit with a minimum rank value of: **"
+ str(int(z.xmin))
+ "**, which is the optimal rank *beyond which* the scaling regime of the power law fits best."
)
alpha_warning = "Your alpha value is a bit on the high side, which means that the distribution over words in this dataset is a bit unnatural. This could be due to non-language items throughout the dataset."
xmin_warning = "The minimum rank for this fit is a bit on the high side, which means that the frequencies of your most common words aren't distributed as would be expected by Zipf's law."
fit_results_table = pd.DataFrame.from_dict(
{
r"Alpha:": [str("%.2f" % z.alpha)],
"KS distance:": [str("%.2f" % z.ks_distance)],
"Min rank:": [str("%s" % int(z.xmin))],
},
columns=["Results"],
orient="index",
)
fit_results_table.index.name = column_id
st.caption(
"Use this widget for the counts of different words in your dataset, measuring the difference between the observed count and the expected count under Zipf's law."
)
st.markdown(_ZIPF_CAPTION)
st.write(
"""
A Zipfian distribution follows the power law: $p(x) \propto x^{-α}$
with an ideal α value of 1."""
)
st.markdown(
"In general, an alpha greater than 2 or a minimum rank greater than 10 (take with a grain of salt) means that your distribution is relativaly _unnatural_ for natural language. This can be a sign of mixed artefacts in the dataset, such as HTML markup."
)
st.markdown(
"Below, you can see the counts of each word in your dataset vs. the expected number of counts following a Zipfian distribution."
)
st.markdown("-----")
st.write("### Here is your dataset's Zipf results:")
st.dataframe(fit_results_table)
st.write(zipf_summary)
# TODO: Nice UI version of the content in the comments.
# st.markdown("\nThe KS test p-value is < %.2f" % z.ks_test.pvalue)
# if z.ks_test.pvalue < 0.01:
# st.markdown(
# "\n Great news! Your data fits a powerlaw with a minimum KS " "distance of %.4f" % z.distance)
# else:
# st.markdown("\n Sadly, your data does not fit a powerlaw. =(")
# st.markdown("Checking the goodness of fit of our observed distribution")
# st.markdown("to the hypothesized power law distribution")
# st.markdown("using a Kolmogorov–Smirnov (KS) test.")
st.plotly_chart(zipf_fig, use_container_width=True)
if z.alpha > 2:
st.markdown(alpha_warning)
if z.xmin > 5:
st.markdown(xmin_warning)
except:
st.write("Under construction!")
def npmi_widget(dstats, column_id=""):
"""
Part of the UI, but providing for interaction.
:param column_id:
:param dstats:
:return:
"""
min_vocab = dstats.min_vocab_count
npmi_stats = dstats.npmi_obj
available_terms = npmi_stats.avail_identity_terms
with st.expander(f"Word Association{column_id}: nPMI", expanded=False):
if npmi_stats and len(available_terms) > 0:
expander_npmi_description(min_vocab)
st.markdown("-----")
term1 = st.selectbox(
f"What is the first term you want to select?{column_id}",
available_terms,
)
term2 = st.selectbox(
f"What is the second term you want to select?{column_id}",
reversed(available_terms),
)
try:
joint_npmi_df = npmi_stats.get_display(term1, term2)
npmi_show(joint_npmi_df)
except Exception as e:
logs.exception(e)
st.markdown(
"**WARNING!** The nPMI for these terms has not been"
" pre-computed, please re-run caching."
)
else:
st.markdown("No words found co-occurring with both of the selected identity"
" terms.")
def npmi_show(paired_results):
if paired_results.empty:
st.markdown(
"No words that co-occur enough times for results! Or there's a 🐛."
" Or we're still computing this one. 🤷")
else:
logs.debug("Results to be shown in streamlit are")
logs.debug(paired_results)
s = pd.DataFrame(
paired_results.sort_values(paired_results.columns[0], ascending=True))
s.index.name = "word"
bias_col = s.filter(like="bias").columns
#count_cols = s.filter(like="count").columns
# Keep the dataframe from being crazy big.
if s.shape[0] > 10000:
bias_thres = max(abs(s[s[0]][5000]),
abs(s[s[0]][-5000]))
logs.info(f"filtering with bias threshold: {bias_thres}")
s_filtered = s[s[0].abs() > bias_thres]
else:
s_filtered = s
cm = sns.palplot(sns.diverging_palette(270, 36, s=99, l=48, n=16))
out_df = s_filtered.style.background_gradient(subset=bias_col, cmap=cm).format(formatter="{:,.3f}").set_properties(**{"align": "center", "width":"100em"}).set_caption("nPMI scores between the selected identity terms and the words they both co-occur with")
#set_properties(subset=count_cols, **{"width": "10em", "text-align": "center"}).
# .format(subset=count_cols, formatter=int).
#.format(subset=bias_col, formatter="{:,.3f}")
st.write("### Here is your dataset's bias results:")
st.dataframe(out_df)
| data-measurements-main | src/utils/gradio_utils.py |
# flake8: noqa
# Copyright 2022 The HuggingFace Data-Measurements Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Lint as: python3
# pylint: enable=line-too-long
# pylint: disable=g-import-not-at-top,g-bad-import-order,wrong-import-position
__version__ = "0.1.0.dev0"
from packaging import version
from data_measurements.measurement_suite import DataMeasurementSuite
SCRIPTS_VERSION = "main" if version.parse(__version__).is_devrelease else __version__
del version
| data-measurements-main | src/data_measurements/__init__.py |
from typing import Callable, Dict, List, Optional, Type
from datasets import Dataset, load_dataset
from data_measurements.measurements import (
DataMeasurement,
DataMeasurementFactory,
DataMeasurementResults,
)
from data_measurements.measurements.base import Widget
class DataMeasurementSuite:
def __init__(
self,
dataset: str,
feature: str,
split: str,
measurements: List[Type[DataMeasurement]],
tokenizer: Optional[Callable[[str], List[str]]] = None,
label: Optional[str] = None,
):
# TODO: TEMPORARY
self.dataset: Dataset = load_dataset(dataset, split=split)
self.measurements = [
DataMeasurementFactory.create(m, tokenizer=tokenizer, feature=feature, label=label) for m in measurements
]
def run(self) -> Dict[str, DataMeasurementResults]:
return {m.name: m.measure(dataset=self.dataset) for m in self.measurements}
@property
def widgets(self) -> List[Widget]:
return [m.widget for m in self.measurements]
| data-measurements-main | src/data_measurements/measurement_suite.py |
from datasets import Dataset
import pandas as pd
import gradio as gr
import nltk
from nltk.corpus import stopwords
from data_measurements.measurements.base import (
DataMeasurement,
DataMeasurementResults,
TokenizedDatasetMixin,
Widget
)
from data_measurements.measurements.text_duplicates import TextDuplicates
import utils
logs = utils.prepare_logging(__file__)
CNT = "count"
VOCAB = "vocab"
PROP = "proportion"
# TODO: Read this in depending on chosen language / expand beyond english
nltk.download("stopwords", quiet=True)
_CLOSED_CLASS = (
stopwords.words("english")
+ ["t", "n", "ll", "d", "s"]
+ ["wasn", "weren", "won", "aren", "wouldn", "shouldn", "didn", "don",
"hasn", "ain", "couldn", "doesn", "hadn", "haven", "isn", "mightn",
"mustn", "needn", "shan", "would", "could", "dont"]
+ [str(i) for i in range(0, 99)]
)
_TOP_N = 100
class GeneralStatsResults(DataMeasurementResults):
def __init__(
self,
total_words,
total_open_words,
sorted_top_vocab_df,
text_nan_count,
dups_frac,
):
self.total_words = total_words
self.total_open_words = total_open_words
self.sorted_top_vocab_df = sorted_top_vocab_df
self.text_nan_count = text_nan_count
self.dups_frac = dups_frac
def __eq__(self, other):
pass
def to_figure(self):
pass
class GeneralStatsWidget(Widget):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.general_stats = gr.Markdown(render=False)
self.general_stats_top_vocab = gr.DataFrame(render=False)
self.general_stats_missing = gr.Markdown(render=False)
self.general_stats_duplicates = gr.Markdown(render=False)
def render(self):
with gr.TabItem(f"General Text Statistics"):
self.general_stats.render()
self.general_stats_missing.render()
self.general_stats_duplicates.render()
self.general_stats_top_vocab.render()
def update(self, results: GeneralStatsResults):
general_stats_text = f"""
Use this widget to check whether the terms you see most represented in the dataset make sense for the goals of the dataset.
There are {str(results.total_words)} total words.
There are {results.total_open_words} after removing closed class words.
The most common [open class words](https://dictionary.apa.org/open-class-words) and their counts are:
"""
top_vocab = pd.DataFrame(results.sorted_top_vocab_df).round(4)
missing_text = (
f"There are {results.text_nan_count} missing values in the dataset"
)
if results.dups_frac > 0:
dupes_text = f"The dataset is {round(results.dups_frac * 100, 2)}% duplicates, For more information about the duplicates, click the 'Duplicates' tab."
else:
dupes_text = "There are 0 duplicate items in the dataset"
return {
self.general_stats: general_stats_text,
self.general_stats_top_vocab: top_vocab,
self.general_stats_missing: missing_text,
self.general_stats_duplicates: dupes_text,
}
@property
def output_components(self):
return [
self.general_stats,
self.general_stats_top_vocab,
self.general_stats_missing,
self.general_stats_duplicates,
]
def add_events(self, state: gr.State):
pass
def count_vocab_frequencies(dataset: Dataset):
return (
pd.DataFrame({"tokenized": dataset["tokenized_text"]})
.tokenized.explode()
.value_counts()
.to_frame(name="count")
)
def calc_p_word(word_count_df):
word_count_df[PROP] = word_count_df[CNT] / float(sum(word_count_df[CNT]))
vocab_counts_df = pd.DataFrame(
word_count_df.sort_values(by=CNT, ascending=False))
vocab_counts_df[VOCAB] = vocab_counts_df.index
return vocab_counts_df
def filter_vocab(vocab_counts_df):
# TODO: Add warnings (which words are missing) to log file?
filtered_vocab_counts_df = vocab_counts_df.drop(_CLOSED_CLASS, errors="ignore")
filtered_count = filtered_vocab_counts_df[CNT]
filtered_count_denom = float(sum(filtered_vocab_counts_df[CNT]))
filtered_vocab_counts_df[PROP] = filtered_count / filtered_count_denom
return filtered_vocab_counts_df
class GeneralStats(TokenizedDatasetMixin, DataMeasurement):
name = "general_stats"
widget = GeneralStatsWidget
def measure(self, dataset: Dataset) -> GeneralStatsResults:
dataset = self.tokenize_dataset(dataset)
word_count_df = count_vocab_frequencies(dataset)
vocab_counts_df = calc_p_word(word_count_df)
total_words = len(vocab_counts_df)
vocab_counts_filtered_df = filter_vocab(vocab_counts_df)
total_open_words = len(vocab_counts_filtered_df)
sorted_top_vocab_df = vocab_counts_filtered_df.sort_values(
"count", ascending=False
).head(_TOP_N)
text_nan_count = int(pd.DataFrame({"tokenized": dataset["tokenized_text"]}).isnull().sum().sum())
dups_frac = TextDuplicates(feature=self.feature).measure(dataset).duplicate_fraction
return GeneralStatsResults(
total_words=total_words,
total_open_words=total_open_words,
sorted_top_vocab_df=sorted_top_vocab_df,
text_nan_count=text_nan_count,
dups_frac=dups_frac,
)
| data-measurements-main | src/data_measurements/measurements/general_stats.py |
from statistics import mean, stdev
import gradio as gr
import matplotlib.pyplot as plt
import seaborn as sns
from datasets import Dataset
from pandas import DataFrame
from data_measurements.measurements.base import (
DataMeasurement,
DataMeasurementResults,
TokenizedDatasetMixin,
Widget
)
class TextLengthsResults(DataMeasurementResults):
def __init__(
self,
average_instance_length: float,
standard_dev_instance_length: float,
num_instance_lengths: int,
lengths: DataFrame,
):
super().__init__()
self.average_instance_length = average_instance_length
self.standard_dev_instance_length = standard_dev_instance_length
self.num_instance_lengths = num_instance_lengths
self.lengths = lengths
def __eq__(self, other):
if isinstance(other, TextLengthsResults):
try:
assert self.average_instance_length == other.average_instance_length
assert self.standard_dev_instance_length == other.standard_dev_instance_length
assert self.num_instance_lengths == other.num_instance_lengths
assert all(self.lengths == other.lengths)
return True
except AssertionError:
return False
else:
return False
def to_figure(self):
# TODO: Copy and pasted... clean it and test
# TODO: Write it OOP-style if possible (see the matplotlib guide)
fig, axs = plt.subplots(figsize=(15, 6), dpi=150)
plt.xlabel("Number of tokens")
plt.title("Binned counts of text lengths, with kernel density estimate and ticks for each instance.")
sns.histplot(data=self.lengths, kde=True, ax=axs, legend=False)
sns.rugplot(data=self.lengths, ax=axs)
return fig
def update_text_length_df(length, results: TextLengthsResults):
return DataFrame(results.lengths[results.lengths == length])
class TextLengthsWidget(Widget):
def __init__(self):
self.text_length_distribution_plot = gr.Plot(render=False)
self.text_length_explainer = gr.Markdown(render=False)
self.text_length_drop_down = gr.Dropdown(render=False)
self.text_length_df = gr.DataFrame(render=False)
def render(self):
with gr.TabItem("Text Lengths"):
gr.Markdown(
"Use this widget to identify outliers, particularly suspiciously long outliers."
)
gr.Markdown(
"Below, you can see how the lengths of the text instances in your "
"dataset are distributed."
)
gr.Markdown(
"Any unexpected peaks or valleys in the distribution may help to "
"identify instances you want to remove or augment."
)
gr.Markdown(
"### Here is the count of different text lengths in " "your dataset:"
)
# When matplotlib first creates this, it's a Figure.
# Once it's saved, then read back in,
# it's an ndarray that must be displayed using st.image
# (I know, lame).
self.text_length_distribution_plot.render()
self.text_length_explainer.render()
self.text_length_drop_down.render()
self.text_length_df.render()
def update(self, results: TextLengthsResults):
explainer_text = (
"The average length of text instances is **"
+ str(round(results.average_instance_length, 2))
+ " words**, with a standard deviation of **"
+ str(round(results.standard_dev_instance_length, 2))
+ "**."
)
# TODO: Add text on choosing the length you want to the dropdown.
output = {
self.text_length_distribution_plot: results.to_figure(),
self.text_length_explainer: explainer_text,
}
if results.lengths is not None:
import numpy as np
choices = np.sort(results.lengths.unique())[
::-1
].tolist()
output[self.text_length_drop_down] = gr.Dropdown.update(
choices=choices, value=choices[0]
)
output[self.text_length_df] = update_text_length_df(choices[0], results)
else:
output[self.text_length_df] = gr.update(visible=False)
output[self.text_length_drop_down] = gr.update(visible=False)
return output
@property
def output_components(self):
return [
self.text_length_distribution_plot,
self.text_length_explainer,
self.text_length_drop_down,
self.text_length_df,
]
def add_events(self, state: gr.State):
self.text_length_drop_down.change(
update_text_length_df,
inputs=[self.text_length_drop_down, state],
outputs=[self.text_length_df],
)
class TextLengths(TokenizedDatasetMixin, DataMeasurement):
name = "text_lengths"
widget = TextLengthsWidget
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def measure(self, dataset: Dataset) -> TextLengthsResults:
# TODO: See if it's possible to do the tokenization with a decorator or something...
dataset = self.tokenize_dataset(dataset)
dataset = dataset.map(lambda x: {**x, "length": len(x["tokenized_text"])})
df = dataset.to_pandas()
df["length"] = df.tokenized_text.apply(len)
avg_length = mean(df.length)
std_length = stdev(df.length)
num_uniq_lengths = len(df.length.unique())
return TextLengthsResults(
average_instance_length=avg_length,
standard_dev_instance_length=std_length,
num_instance_lengths=num_uniq_lengths,
lengths=df.length,
)
| data-measurements-main | src/data_measurements/measurements/text_lengths.py |
from .base import DataMeasurement, DataMeasurementFactory, DataMeasurementResults
from .cooccurences import Cooccurences, CooccurencesResults
from .general_stats import GeneralStats, GeneralStatsResults
from .label_distribution import LabelDistribution, LabelDistributionResults
from .pmi import PMI, PMIResults
from .text_duplicates import TextDuplicates, TextDuplicatesResults
from .text_lengths import TextLengths, TextLengthsResults
__all__ = [
"DataMeasurement",
"DataMeasurementFactory",
"DataMeasurementResults",
"Cooccurences",
"CooccurencesResults",
"GeneralStats",
"GeneralStatsResults",
"LabelDistribution",
"LabelDistributionResults",
"PMI",
"PMIResults",
"TextDuplicates",
"TextDuplicatesResults",
"TextLengths",
"TextLengthsResults",
]
| data-measurements-main | src/data_measurements/measurements/__init__.py |
from datasets import Dataset
import utils.dataset_utils as ds_utils
import gradio as gr
from typing import Dict
from data_measurements.measurements.base import DataMeasurement, DataMeasurementResults, EvaluateMixin, Widget
class TextDuplicatesResults(DataMeasurementResults):
def __init__(
self,
duplicate_fraction: float,
duplicates_dict: Dict,
):
self.duplicate_fraction = duplicate_fraction
self.duplicates_dict = duplicates_dict
def __eq__(self, other):
if isinstance(other, TextDuplicatesResults):
try:
assert self.duplicate_fraction == other.duplicate_fraction
return True
except AssertionError:
return False
else:
return False
def to_figure(self):
pass
class TextDuplicatesWidget(Widget):
def __init__(self):
duplicates_text = f"""
Use this widget to identify text strings that appear more than once.
A model's training and testing may be negatively affected by unwarranted duplicates ([Lee et al., 2021](https://arxiv.org/abs/2107.06499))
------
### Here is the list of all the duplicated items and their counts in the dataset.
"""
self.duplicates_intro = gr.Markdown(render=False, value=duplicates_text)
self.duplicates_df = gr.DataFrame(render=False)
self.duplicates_text = gr.Markdown(render=False)
def render(self):
with gr.TabItem(f"Duplicates"):
self.duplicates_intro.render()
self.duplicates_text.render()
self.duplicates_df.render()
def update(self, results: TextDuplicatesResults):
output = {}
if not results.duplicates_dict:
output[self.duplicates_df] = gr.DataFrame.update(visible=False)
output[self.duplicates_text] = gr.Markdown.update(visible=True,
value="There are no duplicates in this dataset! 🥳")
else:
dupes_df_tmp = ds_utils.counter_dict_to_df(results.duplicates_dict, key_as_column=True)
dupes_df_tmp.columns = ["instance", "count"]
# Nice to have the counts show up first, because the instances
# can be quite long (and run off the page)
dupes_df = dupes_df_tmp[["count", "instance"]]
output[self.duplicates_df] = gr.DataFrame.update(visible=True, value=dupes_df)
duplicates_text = f"The fraction of data that is duplicate is {str(round(results.duplicate_fraction, 4))}"
output[self.duplicates_text] = gr.Markdown.update(value=duplicates_text, visible=True)
return output
@property
def output_components(self):
return [
self.duplicates_text,
self.duplicates_df,
]
def add_events(self, state: gr.State):
pass
class TextDuplicates(EvaluateMixin, DataMeasurement):
name = "text_duplicates"
widget = TextDuplicatesWidget
def measure(self, dataset: Dataset) -> TextDuplicatesResults:
# TODO: list_duplicates is memory-intensive for large datasets
# TODO: Consider making that an option, not the default.
metric_output = super().run_metric(dataset, list_duplicates=True)
return TextDuplicatesResults(
duplicate_fraction=metric_output["duplicate_fraction"],
duplicates_dict=metric_output.get("duplicates_dict", {}),
)
| data-measurements-main | src/data_measurements/measurements/text_duplicates.py |
import numpy.typing as np
import pandas as pd
from datasets import Dataset
from sklearn.preprocessing import MultiLabelBinarizer
from data_measurements.measurements.base import DataMeasurement, DataMeasurementResults, TokenizedDatasetMixin
def count_words_per_sentence(dataset, vocabulary) -> np.NDArray:
mlb = MultiLabelBinarizer(classes=vocabulary)
return mlb.fit_transform(dataset["tokenized_text"])
class CooccurencesResults(DataMeasurementResults):
def __init__(self, matrix: pd.DataFrame):
self.matrix = matrix
def __eq__(self, other):
if isinstance(other, CooccurencesResults):
try:
return True
except AssertionError:
return False
else:
return False
def to_figure(self):
pass
class Cooccurences(TokenizedDatasetMixin, DataMeasurement):
# TODO: Closed Class words should be included...
name = "cooccurences"
identity_terms = [
"man",
"woman",
"non-binary",
"gay",
"lesbian",
"queer",
"trans",
"straight",
"cis",
"she",
"her",
"hers",
"he",
"him",
"his",
"they",
"them",
"their",
"theirs",
"himself",
"herself",
]
# TODO: Locked at 1 right now, make this parameterized?
min_count = 1
# min_count = 10
def measure(self, dataset: Dataset) -> CooccurencesResults:
dataset = self.tokenize_dataset(dataset)
word_count_df = count_vocab_frequencies(dataset)
vocabulary = word_count_df.index
word_counts_per_sentence = count_words_per_sentence(dataset, vocabulary)
present_terms = vocabulary.intersection(self.identity_terms)
min_count = word_count_df.loc[present_terms] >= self.min_count
present_terms = min_count.loc[min_count["count"]].index
subgroup = pd.DataFrame(word_counts_per_sentence).T.set_index(vocabulary).loc[present_terms].T
matrix = pd.DataFrame(word_counts_per_sentence.T.dot(subgroup))
matrix.columns = present_terms
matrix.index = vocabulary
return CooccurencesResults(matrix=matrix)
| data-measurements-main | src/data_measurements/measurements/cooccurences.py |
from datasets import Dataset
from data_measurements.measurements.cooccurences import Cooccurences, CooccurencesResults
class PMIResults(CooccurencesResults):
pass
class PMI(Cooccurences):
name = "PMI"
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def measure(self, dataset: Dataset) -> PMIResults:
cooccurences = super().measure(dataset)
# calc_p_word(word_count_df)
print(self.vocab_counts_df["count"])
# # Calculation of p(subgroup)
# subgroup_prob = self.vocab_counts_df.loc[subgroup]["proportion"]
# # Calculation of p(subgroup|word) = count(subgroup,word) / count(word)
# # Because the indices match (the vocab words),
# # this division doesn't need to specify the index (I think?!)
# vocab_cooc_df.columns = ["cooc"]
# p_subgroup_g_word = (
# vocab_cooc_df["cooc"] / self.vocab_counts_df["count"])
# logs.info("p_subgroup_g_word is")
# logs.info(p_subgroup_g_word)
# pmi_df = pd.DataFrame()
# pmi_df[subgroup] = np.log(p_subgroup_g_word / subgroup_prob).dropna()
| data-measurements-main | src/data_measurements/measurements/pmi.py |
import abc
from abc import ABC
from typing import Callable, Dict, List, Type
import evaluate
from datasets import Dataset
from evaluate import load as load_metric
import gradio as gr
class DataMeasurementResults(ABC):
@abc.abstractmethod
def to_figure(self):
raise NotImplementedError()
@abc.abstractmethod
def __eq__(self, other):
raise NotImplementedError()
class Widget(ABC):
@abc.abstractmethod
def render(self):
pass
@abc.abstractmethod
def update(self, results: DataMeasurementResults):
pass
@property
@abc.abstractmethod
def output_components(self):
pass
@abc.abstractmethod
def add_events(self, state: gr.State):
pass
class DataMeasurement(ABC):
def __init__(self, feature: str, *args, **kwargs):
self.feature = feature
@property
@abc.abstractmethod
def name(self):
raise NotImplementedError()
@property
@abc.abstractmethod
def widget(self):
raise NotImplementedError()
@abc.abstractmethod
def measure(self, dataset) -> DataMeasurementResults:
raise NotImplementedError()
@classmethod
def standalone(cls, dataset, *args, **kwargs):
with gr.Blocks() as demo:
measurement = cls(*args, **kwargs)
results = measurement.measure(dataset)
widget = measurement.widget()
widget.render()
def update_ui():
return widget.update(results)
demo.load(
update_ui,
inputs=[],
outputs=widget.output_components
)
return demo
class DataMeasurementFactory:
@classmethod
def create(cls, measurement: Type[DataMeasurement], *args, **kwargs):
arguments = {"feature": kwargs["feature"]}
if issubclass(measurement, TokenizedDatasetMixin):
arguments["tokenizer"] = kwargs["tokenizer"]
if issubclass(measurement, LabelMeasurementMixin):
arguments["feature"] = kwargs["label"]
return measurement(**arguments)
class EvaluateMixin:
name: str
feature: str
def __init__(self, *args, **kwargs):
self.metric: evaluate.EvaluationModule = load_metric(self.name)
super().__init__(*args, **kwargs)
def run_metric(self, dataset: Dataset, *args, **kwargs) -> Dict:
return self.metric.compute(data=dataset[self.feature], *args, **kwargs)
class TokenizedDatasetMixin:
tokenizer: Callable[[str], List[str]]
feature: str
def __init__(self, tokenizer: Callable[[str], List[str]], *args, **kwargs):
self.tokenizer = tokenizer
super().__init__(*args, **kwargs)
def tokenize_dataset(self, dataset: Dataset) -> Dataset:
return dataset.map(lambda x: {**x, "tokenized_text": self.tokenizer(x[self.feature])})
class LabelMeasurementMixin:
pass
| data-measurements-main | src/data_measurements/measurements/base.py |
from typing import Dict, List
import plotly.express as px
from datasets import Dataset
import gradio as gr
from data_measurements.measurements.base import (
DataMeasurement,
DataMeasurementResults,
EvaluateMixin,
LabelMeasurementMixin,
Widget
)
import utils
logs = utils.prepare_logging(__file__)
class LabelDistributionResults(DataMeasurementResults):
def __init__(self, label_distribution: Dict[str, List[float]], label_skew: float):
self.label_distribution = label_distribution
self.label_skew = label_skew
def __eq__(self, other):
if isinstance(other, LabelDistributionResults):
try:
assert self.label_distribution == other.label_distribution
assert self.label_skew == other.label_skew
return True
except AssertionError:
return False
else:
return False
def to_figure(self):
fig_labels = px.pie(
names=self.label_distribution["labels"],
values=self.label_distribution["fractions"],
)
return fig_labels
class LabelDistributionWidget(Widget):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.label_dist_plot = gr.Plot(render=False, visible=False)
self.label_dist_no_label_text = gr.Markdown(
value="No labels were found in the dataset", render=False, visible=False
)
self.label_dist_accordion = gr.Accordion(render=False, label="", open=False)
def render(self):
with gr.TabItem(label="Label Distribution"):
gr.Markdown(
"Use this widget to see how balanced the labels in your dataset are."
)
self.label_dist_plot.render()
self.label_dist_no_label_text.render()
def update(self, results: LabelDistributionResults):
output = {
self.label_dist_plot: gr.Plot.update(
value=results.to_figure(), visible=True
),
self.label_dist_no_label_text: gr.Markdown.update(visible=False),
}
return output
@property
def output_components(self):
return [self.label_dist_plot, self.label_dist_no_label_text]
def add_events(self, state: gr.State):
pass
# TODO: Implement a CachedMeasurementMixin for handling fetching from a local cache (for all measurements)
class LabelDistribution(LabelMeasurementMixin, EvaluateMixin, DataMeasurement):
name = "label_distribution"
widget = LabelDistributionWidget
def measure(self, dataset: Dataset) -> LabelDistributionResults:
results = super().run_metric(dataset)
return LabelDistributionResults(
label_distribution=results["label_distribution"],
label_skew=results["label_skew"],
)
| data-measurements-main | src/data_measurements/measurements/label_distribution.py |
from sklearn.feature_extraction.text import CountVectorizer
from data_measurements import DataMeasurementSuite
from data_measurements.measurements import Cooccurences
tokenizer = CountVectorizer(token_pattern="(?u)\\b\\w+\\b").build_tokenizer()
import time
t = time.time()
suite = DataMeasurementSuite(
dataset="hate_speech18",
feature="text",
label="label",
split="train",
tokenizer=tokenizer,
measurements=[Cooccurences],
)
results = suite.run()
elapsed = time.time() - t
print(elapsed)
# results["cooccurences"]
| data-measurements-main | src/sample_scripts/cooccurence_sample.py |
from data_measurements.measurements import TextDuplicates
from datasets import Dataset
dataset = Dataset.from_dict(
{
"text": ["Hello", "World", "Hello", "Foo Bar", "wasn", ""],
"label": [1, 2, 1, 1, 0, 0],
}
)
def tokenize(sentence: str):
return sentence.split()
TextDuplicates.standalone(dataset=dataset, feature="text").launch()
| data-measurements-main | src/sample_scripts/launch_widget.py |
from transformers import AutoTokenizer
from data_measurements import DataMeasurementSuite
from data_measurements.measurements import LabelDistribution, TextDuplicates, TextLengths
gpt2_tokenizer = AutoTokenizer.from_pretrained("gpt2")
def tokenizer(x):
return gpt2_tokenizer(x)["input_ids"]
suite = DataMeasurementSuite(
dataset="hate_speech18",
feature="text",
label="label",
split="train",
tokenizer=tokenizer,
measurements=[
TextDuplicates,
TextLengths,
LabelDistribution,
],
)
results = suite.run()
results["text_lengths"].to_figure().show()
results["label_distribution"].to_figure().show()
| data-measurements-main | src/sample_scripts/sample_script.py |
import json
import os
import tempfile
import time
from io import BytesIO
from mimetypes import guess_extension
from typing import Any, Dict, List, Optional, Tuple
import librosa
import psutil
import requests
import soundfile
import timm
import torch
import uvicorn
from asteroid import separate
from asteroid.models import BaseModel as AsteroidBaseModel
from espnet2.bin.asr_inference import Speech2Text
from espnet2.bin.tts_inference import Text2Speech
from PIL import Image
from starlette.applications import Starlette
from starlette.background import BackgroundTask
from starlette.middleware import Middleware
from starlette.middleware.cors import CORSMiddleware
from starlette.requests import Request
from starlette.responses import FileResponse, JSONResponse
from starlette.routing import Route
from transformers import (
Speech2TextForConditionalGeneration,
Speech2TextProcessor,
Wav2Vec2ForCTC,
Wav2Vec2Tokenizer,
)
HF_HEADER_COMPUTE_TIME = "x-compute-time"
# Type alias for all models
AnyModel = Any
AnyTokenizer = Any
EXAMPLE_TTS_EN_MODEL_ID = (
"julien-c/ljspeech_tts_train_tacotron2_raw_phn_tacotron_g2p_en_no_space_train"
)
EXAMPLE_TTS_ZH_MODEL_ID = "julien-c/kan-bayashi_csmsc_tacotron2"
EXAMPLE_ASR_EN_MODEL_ID = "julien-c/mini_an4_asr_train_raw_bpe_valid"
EXAMPLE_SEP_ENH_MODEL_ID = "mhu-coder/ConvTasNet_Libri1Mix_enhsingle"
EXAMPLE_SEP_SEP_MODEL_ID = "julien-c/DPRNNTasNet-ks16_WHAM_sepclean"
WAV2VEV2_MODEL_IDS = [
"facebook/wav2vec2-base-960h",
"facebook/wav2vec2-large-960h-lv60-self",
"facebook/wav2vec2-large-xlsr-53-dutch",
"facebook/wav2vec2-large-xlsr-53-french",
"facebook/wav2vec2-large-xlsr-53-german",
"facebook/wav2vec2-large-xlsr-53-italian",
"facebook/wav2vec2-large-xlsr-53-spanish",
"facebook/wav2vec2-large-xlsr-53-portuguese",
]
SPEECH_TO_TEXT_MODEL_IDS = [
"facebook/s2t-small-librispeech-asr",
"facebook/s2t-medium-librispeech-asr",
"facebook/s2t-large-librispeech-asr",
"facebook/s2t-small-mustc-en-de-st",
"facebook/s2t-small-mustc-en-es-st",
"facebook/s2t-small-mustc-en-fr-st",
"facebook/s2t-small-mustc-en-it-st",
"facebook/s2t-small-mustc-en-nl-st",
"facebook/s2t-small-mustc-en-pt-st",
"facebook/s2t-small-mustc-en-ro-st",
"facebook/s2t-small-mustc-en-ru-st",
]
with open("data/imagenet-simple-labels.json") as f:
IMAGENET_LABELS: List[str] = json.load(f)
## ^ from gh.com/anishathalye/imagenet-simple-labels
TTS_MODELS: Dict[str, AnyModel] = {}
ASR_MODELS: Dict[str, AnyModel] = {}
SEP_MODELS: Dict[str, AnyModel] = {}
ASR_HF_MODELS: Dict[str, Tuple[AnyModel, AnyTokenizer]] = {}
TIMM_MODELS: Dict[str, torch.nn.Module] = {}
def home(request: Request):
return JSONResponse({"ok": True})
def health(_):
process = psutil.Process(os.getpid())
mem_info = process.memory_info()
return JSONResponse(
{**process.as_dict(attrs=["memory_percent"]), "rss": mem_info.rss}
)
def list_models(_):
all_models = {
**TTS_MODELS,
**ASR_MODELS,
**SEP_MODELS,
**{k: v[0] for k, v in ASR_HF_MODELS.items()},
**TIMM_MODELS,
}
return JSONResponse({k: v.__class__.__name__ for k, v in all_models.items()})
async def post_inference_tts(request: Request, model: AnyModel):
start = time.time()
try:
body = await request.json()
except:
return JSONResponse(status_code=400, content="Invalid JSON body")
print(body)
text = body["text"]
outputs = model(text)
speech = outputs[0]
with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as tmp:
soundfile.write(tmp.name, speech.numpy(), model.fs, "PCM_16")
return FileResponse(
tmp.name,
headers={HF_HEADER_COMPUTE_TIME: "{:.3f}".format(time.time() - start)},
background=BackgroundTask(lambda f: os.unlink(f), tmp.name),
)
async def post_inference_asr(
request: Request,
model_id: str,
):
start = time.time()
content_type = request.headers["content-type"].split(";")[0]
if content_type == "application/json":
body = await request.json()
if "url" not in body:
return JSONResponse(
{"ok": False, "message": f"Invalid json, no url key"}, status_code=400
)
url = body["url"]
r = requests.get(url, stream=True)
file_ext: Optional[str] = guess_extension(
r.headers.get("content-type", ""), strict=False
)
blob = r.content
else:
file_ext: Optional[str] = guess_extension(content_type, strict=False)
try:
blob = await request.body()
except Exception as exc:
return JSONResponse(
{"ok": False, "message": f"Invalid body: {exc}"}, status_code=400
)
with tempfile.NamedTemporaryFile(suffix=file_ext) as tmp:
print(tmp, tmp.name)
tmp.write(blob)
tmp.flush()
try:
speech, rate = soundfile.read(tmp.name, dtype="float32")
except:
try:
speech, rate = librosa.load(tmp.name, sr=16_000)
except Exception as exc:
return JSONResponse(
{"ok": False, "message": f"Invalid audio: {exc}"}, status_code=400
)
if len(speech.shape) > 1:
# ogg can take dual channel input -> take only first input channel in this case
speech = speech[:, 0]
if rate != 16_000:
speech = librosa.resample(speech, rate, 16_000)
##
## model-specific forward pass
if model_id in ASR_HF_MODELS:
if model_id in SPEECH_TO_TEXT_MODEL_IDS:
model, processor = ASR_HF_MODELS.get(model_id)
inputs = processor(speech, return_tensors="pt")
generated_ids = model.generate(
input_ids=inputs["features"], attention_mask=inputs["attention_mask"]
)
text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
else:
model, tokenizer = ASR_HF_MODELS.get(model_id)
input_values = tokenizer(speech, return_tensors="pt").input_values
logits = model(input_values).logits
predicted_ids = torch.argmax(logits, dim=-1)
text = tokenizer.decode(predicted_ids[0])
else:
model = ASR_MODELS.get(model_id)
outputs = model(speech)
text, *_ = outputs[0]
print(text)
return JSONResponse(
{"text": text},
headers={HF_HEADER_COMPUTE_TIME: "{:.3f}".format(time.time() - start)},
)
async def post_inference_sep(request: Request, model: AnyModel):
start = time.time()
try:
body = await request.body()
with tempfile.NamedTemporaryFile() as tmp:
tmp.write(body)
tmp.flush()
wav, fs = separate._load_audio(tmp.name)
except Exception as exc:
return JSONResponse(
{"ok": False, "message": f"Invalid body: {exc}"}, status_code=400
)
# Wav shape: [time, n_chan]
# We only support n_chan = 1 for now.
wav = separate._resample(wav[:, 0], orig_sr=fs, target_sr=int(model.sample_rate))
# Pass wav as [batch, n_chan, time]; here: [1, 1, time]
(est_srcs,) = separate.numpy_separate(model, wav.reshape((1, 1, -1)))
# FIXME: how to deal with multiple sources?
est = est_srcs[0]
with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as tmp:
soundfile.write(tmp.name, est, int(model.sample_rate), "PCM_16")
return FileResponse(
tmp.name,
headers={HF_HEADER_COMPUTE_TIME: "{:.3f}".format(time.time() - start)},
background=BackgroundTask(lambda f: os.unlink(f), tmp.name),
)
async def post_inference_timm(request: Request, model: torch.nn.Module):
start = time.time()
content_type = request.headers["content-type"]
if content_type == "application/json":
body = await request.json()
if "url" not in body:
return JSONResponse(
{"ok": False, "message": f"Invalid json, no url key"}, status_code=400
)
url = body["url"]
img = Image.open(requests.get(url, stream=True).raw)
else:
try:
body = await request.body()
img = Image.open(BytesIO(body))
except Exception as exc:
print(exc)
return JSONResponse(
{"ok": False, "message": f"Unable to open image from request"},
status_code=400,
)
img = img.convert("RGB")
# Data handling config
config = model.default_cfg
if isinstance(config["input_size"], tuple):
img_size = config["input_size"][-2:]
else:
img_size = config["input_size"]
transform = timm.data.transforms_factory.transforms_imagenet_eval(
img_size=img_size,
interpolation=config["interpolation"],
mean=config["mean"],
std=config["std"],
)
input_tensor = transform(img)
input_tensor = input_tensor.unsqueeze(0)
# ^ batch size = 1
with torch.no_grad():
output = model(input_tensor)
probs = output.squeeze(0).softmax(dim=0)
values, indices = torch.topk(probs, k=5)
labels = [IMAGENET_LABELS[i] for i in indices]
return JSONResponse(
[{"label": label, "score": float(values[i])} for i, label in enumerate(labels)],
headers={HF_HEADER_COMPUTE_TIME: "{:.3f}".format(time.time() - start)},
)
async def post_inference(request: Request) -> JSONResponse:
model_id = request.path_params["model_id"]
if model_id in TTS_MODELS:
model = TTS_MODELS.get(model_id)
return await post_inference_tts(request, model)
if model_id in ASR_MODELS or model_id in ASR_HF_MODELS:
return await post_inference_asr(request, model_id)
if model_id in SEP_MODELS:
model = SEP_MODELS.get(model_id)
return await post_inference_sep(request, model)
if model_id in TIMM_MODELS:
model = TIMM_MODELS.get(model_id)
return await post_inference_timm(request, model)
return JSONResponse(status_code=404, content="Unknown or unsupported model")
routes = [
Route("/", home),
Route("/health", health),
Route("/models", list_models),
Route("/models/{model_id:path}", post_inference, methods=["POST"]),
]
middlewares = [
Middleware(
CORSMiddleware,
allow_origins=["*"],
allow_methods=["*"],
allow_headers=["*"],
expose_headers=["*"],
)
]
app = Starlette(debug=True, routes=routes, middleware=middlewares)
if __name__ == "__main__":
## Load all models
start_time = time.time()
for model_id in (EXAMPLE_TTS_EN_MODEL_ID, EXAMPLE_TTS_ZH_MODEL_ID):
model = Text2Speech.from_pretrained(model_id, device="cpu")
TTS_MODELS[model_id] = model
for model_id in (EXAMPLE_ASR_EN_MODEL_ID,):
model = Speech2Text.from_pretrained(model_id, device="cpu")
ASR_MODELS[model_id] = model
for model_id in (EXAMPLE_SEP_ENH_MODEL_ID, EXAMPLE_SEP_SEP_MODEL_ID):
model = AsteroidBaseModel.from_pretrained(model_id)
SEP_MODELS[model_id] = model
for model_id in WAV2VEV2_MODEL_IDS:
model = Wav2Vec2ForCTC.from_pretrained(model_id)
tokenizer = Wav2Vec2Tokenizer.from_pretrained(model_id)
ASR_HF_MODELS[model_id] = (model, tokenizer)
for model_id in SPEECH_TO_TEXT_MODEL_IDS:
model = Speech2TextForConditionalGeneration.from_pretrained(model_id)
processor = Speech2TextProcessor.from_pretrained(model_id)
ASR_HF_MODELS[model_id] = (model, processor)
TIMM_MODELS["julien-c/timm-dpn92"] = timm.create_model(
"dpn92", pretrained=True
).eval()
TIMM_MODELS["sgugger/resnet50d"] = timm.create_model(
"resnet50d", pretrained=True
).eval()
# ^ Those are not in eval mode by default
print("models.loaded", time.time() - start_time)
## Start server
uvicorn.run(app, host="0.0.0.0", port=8000, timeout_keep_alive=0)
# Sample wav file
# wget https://assets.amazon.science/c2/65/08e161cb4e96a7e007d6c3a4fef5/sample02-orig.wav
# ================
# TTS example:
# curl -XPOST --data '{"text": "My name is Julien"}' http://127.0.0.1:8000/models/julien-c/ljspeech_tts_train_tacotron2_raw_phn_tacotron_g2p_en_no_space_train | play -
# curl -XPOST --data '{"text": "请您说得慢些好吗"}' http://127.0.0.1:8000/models/julien-c/kan-bayashi_csmsc_tacotron2 | play -
# or in production:
# curl -XPOST --data '{"text": "My name is Julien"}' http://api-audio.huggingface.co/models/julien-c/ljspeech_tts_train_tacotron2_raw_phn_tacotron_g2p_en_no_space_train | play -
# ================
# ASR example:
# curl -i -H "Content-Type: audio/x-wav" -XPOST --data-binary '@samples/sample02-orig.wav' http://127.0.0.1:8000/models/julien-c/mini_an4_asr_train_raw_bpe_valid
# ================
# ASR wav2vec example:
# curl -i -H "Content-Type: audio/wav" -XPOST --data-binary '@samples/sample02-orig.wav' http://127.0.0.1:8000/models/facebook/wav2vec2-base-960h
# curl -i -H "Content-Type: audio/flac" -XPOST --data-binary '@samples/sample1.flac' http://127.0.0.1:8000/models/facebook/wav2vec2-base-960h
# curl -i -H "Content-Type: audio/webm" -XPOST --data-binary '@samples/chrome.webm' http://127.0.0.1:8000/models/facebook/wav2vec2-base-960h
# curl -i -H "Content-Type: audio/ogg" -XPOST --data-binary '@samples/firefox.oga' http://127.0.0.1:8000/models/facebook/wav2vec2-base-960h
# or in production:
# curl -i -H "Content-Type: audio/wav" -XPOST --data-binary '@samples/sample02-orig.wav' http://api-audio.huggingface.co/models/facebook/wav2vec2-base-960h
# ================
# SEP example:
# curl -XPOST --data-binary '@samples/sample02-orig.wav' http://127.0.0.1:8000/models/mhu-coder/ConvTasNet_Libri1Mix_enhsingle | play -
# ================
# TIMM examples:
# curl -i -H "Content-Type: image/jpeg" -XPOST --data-binary '@samples/plane.jpg' http://127.0.0.1:8000/models/julien-c/timm-dpn92
# curl -i -H "Content-Type: image/jpeg" -XPOST --data-binary '@samples/plane.jpg' http://127.0.0.1:8000/models/sgugger/resnet50d
# curl -i -H "Content-Type: application/json" -XPOST --data '{"url": "https://i.picsum.photos/id/543/536/354.jpg?hmac=O-U6guSk3J8UDMCjnqQHaL8EAOR9yHXZtgA90Bf5UTc"}' http://127.0.0.1:8000/models/julien-c/timm-dpn92
# curl -i -H "Content-Type: application/json" -XPOST --data '{"url": "https://huggingface.co/front/assets/transformers-demo.png"}' http://127.0.0.1:8000/models/sgugger/resnet50d
# or in production:
# curl -i -H "Content-Type: application/json" -XPOST --data '{"url": "https://huggingface.co/front/assets/transformers-demo.png"}' http://api-audio.huggingface.co/models/sgugger/resnet50d
| api-inference-community-master-old | main.py |
import os
import sys
import unittest
from mimetypes import guess_type
SRC_DIR = os.path.join(os.path.dirname(__file__), "..") # isort:skip
sys.path.append(SRC_DIR) # isort:skip
import requests
from main import (
EXAMPLE_ASR_EN_MODEL_ID,
EXAMPLE_SEP_ENH_MODEL_ID,
EXAMPLE_SEP_SEP_MODEL_ID,
EXAMPLE_TTS_EN_MODEL_ID,
EXAMPLE_TTS_ZH_MODEL_ID,
HF_HEADER_COMPUTE_TIME,
WAV2VEV2_MODEL_IDS,
)
ENDPOINT = "http://localhost:8000"
# To test the production env remotely:
if os.environ.get("PRODUCTION") is not None:
ENDPOINT = "http://api-audio.huggingface.co"
AUDIO_SAMPLE_LOCAL_FILES = [
"samples/sample02-orig.wav",
"samples/sample1.flac",
"samples/chrome.webm",
"samples/firefox.oga",
]
AUDIO_SAMPLE_REMOTE_URLS = [
"https://cdn-media.huggingface.co/speech_samples/sample02-orig.wav",
"https://cdn-media.huggingface.co/speech_samples/sample1.flac",
"https://cdn-media.huggingface.co/speech_samples/chrome.webm",
"https://cdn-media.huggingface.co/speech_samples/firefox.oga",
]
def endpoint_model(id: str) -> str:
return f"{ENDPOINT}/models/{id}"
class AuxiliaryEndpointsTest(unittest.TestCase):
def test_home(self):
r = requests.get(ENDPOINT)
r.raise_for_status()
self.assertTrue(r.ok)
def test_list_models(self):
r = requests.get(f"{ENDPOINT}/models")
r.raise_for_status()
models = r.json()
self.assertIsInstance(models, dict)
class TTSTest(unittest.TestCase):
def test_tts_en(self):
r = requests.post(
url=endpoint_model(EXAMPLE_TTS_EN_MODEL_ID),
json={"text": "My name is Julien"},
)
r.raise_for_status()
print(r.headers.get(HF_HEADER_COMPUTE_TIME))
self.assertEqual(r.headers.get("content-type"), "audio/x-wav")
def test_tts_zh(self):
r = requests.post(
url=endpoint_model(EXAMPLE_TTS_ZH_MODEL_ID),
json={"text": "请您说得慢些好吗"},
)
r.raise_for_status()
print(r.headers.get(HF_HEADER_COMPUTE_TIME))
self.assertEqual(r.headers.get("content-type"), "audio/x-wav")
class TimmTest(unittest.TestCase):
def test_resnet50d_file_upload(self):
with open(os.path.join(SRC_DIR, "samples/plane.jpg"), "rb") as f:
r = requests.post(
url=endpoint_model("sgugger/resnet50d"),
data=f,
headers={"content-type": "image/jpeg"},
)
r.raise_for_status()
print(r.headers.get(HF_HEADER_COMPUTE_TIME))
body = r.json()
self.assertIsInstance(body, list)
def test_resnet50d_url(self):
r = requests.post(
url=endpoint_model("sgugger/resnet50d"),
json={"url": "https://huggingface.co/front/assets/transformers-demo.png"},
)
r.raise_for_status()
print(r.headers.get(HF_HEADER_COMPUTE_TIME))
body = r.json()
self.assertIsInstance(body, list)
class ASRTest(unittest.TestCase):
def test_asr_file_upload(self):
# EXAMPLE_ASR_EN_MODEL_ID is too slow,
# let's handle it separately if needed.
for model_id in WAV2VEV2_MODEL_IDS:
for audio_file in AUDIO_SAMPLE_LOCAL_FILES:
with self.subTest():
with open(os.path.join(SRC_DIR, audio_file), "rb") as f:
r = requests.post(
url=endpoint_model(model_id),
data=f,
headers={"content-type": guess_type(audio_file)[0]},
)
r.raise_for_status()
print(r.headers.get(HF_HEADER_COMPUTE_TIME))
body = r.json()
print(body)
self.assertIsInstance(body, dict)
def test_asr_url(self):
# EXAMPLE_ASR_EN_MODEL_ID is too slow,
# let's handle it separately if needed.
for model_id in WAV2VEV2_MODEL_IDS:
for audio_url in AUDIO_SAMPLE_REMOTE_URLS:
with self.subTest():
r = requests.post(
url=endpoint_model(model_id),
json={"url": audio_url},
)
r.raise_for_status()
print(r.headers.get(HF_HEADER_COMPUTE_TIME))
body = r.json()
print(body)
self.assertIsInstance(body, dict)
class SEPTest(unittest.TestCase):
def test_sep_file_upload(self):
for model_id in (EXAMPLE_SEP_ENH_MODEL_ID, EXAMPLE_SEP_SEP_MODEL_ID):
for audio_file in AUDIO_SAMPLE_LOCAL_FILES:
with self.subTest():
with open(os.path.join(SRC_DIR, audio_file), "rb") as f:
r = requests.post(
url=endpoint_model(model_id),
data=f,
headers={"content-type": guess_type(audio_file)[0]},
)
r.raise_for_status()
print(r.headers.get(HF_HEADER_COMPUTE_TIME))
self.assertEqual(r.headers.get("content-type"), "audio/x-wav")
| api-inference-community-master-old | tests/test_requests.py |
#!/usr/bin/env python
""" This script will clone the `datasets` repository in your current directory and parse all currently available
metadata, from the `README.md` yaml headers and the automatically generated json files.
It dumps the results in a `metadata_{current-commit-of-datasets}.json` file.
"""
import json
from pathlib import Path
from subprocess import check_call, check_output
from typing import Dict
import yaml
from apputils import new_state
def metadata_from_readme(f: Path) -> Dict:
with f.open() as fi:
content = [line.rstrip() for line in fi]
if content[0] == "---" and "---" in content[1:]:
yamlblock = "\n".join(content[1 : content[1:].index("---") + 1])
return yaml.safe_load(yamlblock) or dict()
def load_ds_datas():
drepo = Path("datasets")
if drepo.exists() and drepo.is_dir():
check_call(["git", "pull"], cwd=drepo)
else:
check_call(["git", "clone", "https://github.com/huggingface/datasets.git"])
head_sha = check_output(["git", "rev-parse", "HEAD"], cwd=drepo)
datasets_md = dict()
for ddir in sorted((drepo / "datasets").iterdir(), key=lambda d: d.name):
try:
metadata = metadata_from_readme(ddir / "README.md")
except:
metadata = None
if metadata is None or len(metadata) == 0:
metadata = new_state()
try:
with (ddir / "dataset_infos.json").open() as fi:
infos = json.load(fi)
except:
infos = None
datasets_md[ddir.name] = dict(metadata=metadata, infos=infos)
return head_sha.decode().strip(), datasets_md
if __name__ == "__main__":
head_sha, datas = load_ds_datas()
fn = f"metadata_{head_sha}.json"
print(f"writing to '{fn}'")
with open(fn, "w") as fi:
fi.write(json.dumps(datas))
| datasets-tagging-main | build_metadata_file.py |
import json
import logging
from pathlib import Path
from typing import Callable, Dict, List, Tuple
import langcodes as lc
import streamlit as st
import yaml
from datasets.utils.metadata import (
DatasetMetadata,
known_creators,
known_licenses,
known_multilingualities,
known_size_categories,
known_task_ids,
)
from apputils import new_state
st.set_page_config(
page_title="HF Dataset Tagging App",
page_icon="https://huggingface.co/front/assets/huggingface_logo.svg",
layout="wide",
initial_sidebar_state="auto",
)
# XXX: restyling errors as streamlit does not respect whitespaces on `st.error` and doesn't scroll horizontally, which
# generally makes things easier when reading error reports
st.markdown(
"""
<style>
div[role=alert] { overflow-x: scroll}
div.stAlert p { white-space: pre }
</style>
""",
unsafe_allow_html=True,
)
########################
## Helper functions
########################
def load_ds_datas() -> Dict[str, Dict[str, Dict]]:
metada_exports = sorted(
[f for f in Path.cwd().iterdir() if f.name.startswith("metadata_")],
key=lambda f: f.lstat().st_mtime,
reverse=True,
)
if len(metada_exports) == 0:
raise ValueError("need to run ./build_metada_file.py at least once")
with metada_exports[0].open() as fi:
logging.info(f"loaded {metada_exports[0]}")
return json.load(fi)
def split_known(vals: List[str], okset: List[str]) -> Tuple[List[str], List[str]]:
if vals is None:
return [], []
return [v for v in vals if v in okset], [v for v in vals if v not in okset]
def multiselect(
w: st.delta_generator.DeltaGenerator,
title: str,
markdown: str,
values: List[str],
valid_set: List[str],
format_func: Callable = str,
):
valid_values, invalid_values = split_known(values, valid_set)
w.markdown(f"#### {title}")
if len(invalid_values) > 0:
w.markdown("Found the following invalid values:")
w.error(invalid_values)
return w.multiselect(markdown, valid_set, default=valid_values, format_func=format_func)
def validate_dict(w: st.delta_generator.DeltaGenerator, state_dict: Dict):
try:
DatasetMetadata(**state_dict)
w.markdown("✅ This is a valid tagset! 🤗")
except Exception as e:
w.markdown("❌ This is an invalid tagset, here are the errors in it:")
w.error(e)
def map_num_examples_to_size_categories(n: int) -> str:
if n <= 0:
size_cat = "unknown"
elif n < 1000:
size_cat = "n<1K"
elif n < 10000:
size_cat = "1K<n<10K"
elif n < 100000:
size_cat = "10K<n<100K"
elif n < 1000000:
size_cat = "100K<n<1M"
elif n < 10000000:
size_cat = "1M<n<10M"
elif n < 100000000:
size_cat = "10M<n<100M"
elif n < 1000000000:
size_cat = "100M<n<1B"
elif n < 10000000000:
size_cat = "1B<n<10B"
elif n < 100000000000:
size_cat = "10B<n<100B"
elif n < 1000000000000:
size_cat = "100B<n<1T"
else:
size_cat = "n>1T"
return size_cat
def is_state_empty(state: Dict[str, List]) -> bool:
return sum(len(v) if v is not None else 0 for v in state.values()) == 0
state = new_state()
datasets_md = load_ds_datas()
dataset_ids = list(datasets_md.keys())
dataset_id_to_metadata = {name: mds["metadata"] for name, mds in datasets_md.items()}
dataset_id_to_infos = {name: mds["infos"] for name, mds in datasets_md.items()}
########################
## Dataset selection
########################
st.sidebar.markdown(
"""
# HuggingFace Dataset Tagger
This app aims to make it easier to add structured tags to the datasets present in the library.
"""
)
queryparams = st.experimental_get_query_params()
preload = queryparams.get("preload_dataset", list())
preloaded_id = None
initial_state = None
initial_infos, initial_info_cfg = None, None
dataset_selector_index = 0
if len(preload) == 1 and preload[0] in dataset_ids:
preloaded_id, *_ = preload
initial_state = dataset_id_to_metadata.get(preloaded_id)
initial_infos = dataset_id_to_infos.get(preloaded_id)
initial_info_cfg = next(iter(initial_infos)) if initial_infos is not None else None # pick first available config
state = initial_state or new_state()
dataset_selector_index = dataset_ids.index(preloaded_id)
preloaded_id = st.sidebar.selectbox(
label="Choose dataset to load tag set from", options=dataset_ids, index=dataset_selector_index
)
leftbtn, rightbtn = st.sidebar.columns(2)
if leftbtn.button("pre-load"):
initial_state = dataset_id_to_metadata[preloaded_id]
initial_infos = dataset_id_to_infos[preloaded_id]
initial_info_cfg = next(iter(initial_infos)) # pick first available config
state = initial_state or new_state()
st.experimental_set_query_params(preload_dataset=preloaded_id)
if not is_state_empty(state):
if rightbtn.button("flush state"):
state = new_state()
initial_state = None
preloaded_id = None
st.experimental_set_query_params()
if preloaded_id is not None and initial_state is not None:
st.sidebar.markdown(
f"""
---
The current base tagset is [`{preloaded_id}`](https://huggingface.co/datasets/{preloaded_id})
"""
)
validate_dict(st.sidebar, initial_state)
st.sidebar.markdown(
f"""
Here is the matching yaml block:
```yaml
{yaml.dump(initial_state)}
```
"""
)
leftcol, _, rightcol = st.columns([12, 1, 12])
#
# DATASET NAME
#
leftcol.markdown("### Dataset name")
state["pretty_name"] = leftcol.text_area(
"Pick a nice descriptive name for the dataset",
)
#
# TASKS
#
leftcol.markdown("### Supported tasks")
state["task_categories"] = multiselect(
leftcol,
"Task category",
"What categories of task does the dataset support?",
values=state["task_categories"],
valid_set=list(known_task_ids.keys()),
format_func=lambda tg: f"{tg}: {known_task_ids[tg]['description']}",
)
task_specifics = []
for task_category in state["task_categories"]:
specs = multiselect(
leftcol,
f"Specific _{task_category}_ tasks",
f"What specific tasks does the dataset support?",
values=[ts for ts in (state["task_ids"] or []) if ts in known_task_ids[task_category]["options"]],
valid_set=known_task_ids[task_category]["options"],
)
if "other" in specs:
other_task = leftcol.text_input(
"You selected 'other' task. Please enter a short hyphen-separated description for the task:",
value="my-task-description",
)
leftcol.write(f"Registering {task_category}-other-{other_task} task")
specs[specs.index("other")] = f"{task_category}-other-{other_task}"
task_specifics += specs
state["task_ids"] = task_specifics
#
# LANGUAGES
#
leftcol.markdown("### Languages")
state["multilinguality"] = multiselect(
leftcol,
"Monolingual?",
"Does the dataset contain more than one language?",
values=state["multilinguality"],
valid_set=list(known_multilingualities.keys()),
format_func=lambda m: f"{m} : {known_multilingualities[m]}",
)
if "other" in state["multilinguality"]:
other_multilinguality = leftcol.text_input(
"You selected 'other' type of multilinguality. Please enter a short hyphen-separated description:",
value="my-multilinguality",
)
leftcol.write(f"Registering other-{other_multilinguality} multilinguality")
state["multilinguality"][state["multilinguality"].index("other")] = f"other-{other_multilinguality}"
valid_values, invalid_values = list(), list()
for langtag in state["languages"]:
try:
lc.get(langtag)
valid_values.append(langtag)
except:
invalid_values.append(langtag)
leftcol.markdown("#### Languages")
if len(invalid_values) > 0:
leftcol.markdown("Found the following invalid values:")
leftcol.error(invalid_values)
langtags = leftcol.text_area(
"What languages are represented in the dataset? expected format is BCP47 tags separated for ';' e.g. 'en-US;fr-FR'",
value=";".join(valid_values),
)
state["languages"] = langtags.strip().split(";") if langtags.strip() != "" else []
#
# DATASET CREATORS & ORIGINS
#
leftcol.markdown("### Dataset creators")
state["language_creators"] = multiselect(
leftcol,
"Data origin",
"Where does the text in the dataset come from?",
values=state["language_creators"],
valid_set=known_creators["language"],
)
state["annotations_creators"] = multiselect(
leftcol,
"Annotations origin",
"Where do the annotations in the dataset come from?",
values=state["annotations_creators"],
valid_set=known_creators["annotations"],
)
#
# LICENSES
#
state["licenses"] = multiselect(
leftcol,
"Licenses",
"What licenses is the dataset under?",
valid_set=list(known_licenses.keys()),
values=state["licenses"],
format_func=lambda l: f"{l} : {known_licenses[l]}",
)
if "other" in state["licenses"]:
other_license = st.text_input(
"You selected 'other' type of license. Please enter a short hyphen-separated description:",
value="my-license",
)
st.write(f"Registering other-{other_license} license")
state["licenses"][state["licenses"].index("other")] = f"other-{other_license}"
#
# LINK TO SUPPORTED DATASETS
#
pre_select_ext_a = []
if "original" in state["source_datasets"]:
pre_select_ext_a += ["original"]
if any([p.startswith("extended") for p in state["source_datasets"]]):
pre_select_ext_a += ["extended"]
state["source_datasets"] = multiselect(
leftcol,
"Relations to existing work",
"Does the dataset contain original data and/or was it extended from other datasets?",
values=pre_select_ext_a,
valid_set=["original", "extended"],
)
if "extended" in state["source_datasets"]:
pre_select_ext_b = [p.split("|")[1] for p in state["source_datasets"] if p.startswith("extended|")]
extended_sources = multiselect(
leftcol,
"Linked datasets",
"Which other datasets does this one use data from?",
values=pre_select_ext_b,
valid_set=dataset_ids + ["other"],
)
# flush placeholder
state["source_datasets"].remove("extended")
state["source_datasets"] += [f"extended|{src}" for src in extended_sources]
#
# SIZE CATEGORY
#
leftcol.markdown("### Size category")
logging.info(initial_infos[initial_info_cfg]["splits"] if initial_infos is not None else 0)
initial_num_examples = (
sum([dct.get("num_examples", 0) for _split, dct in initial_infos[initial_info_cfg].get("splits", dict()).items()])
if initial_infos is not None
else -1
)
initial_size_cats = map_num_examples_to_size_categories(initial_num_examples)
leftcol.markdown(f"Computed size category from automatically generated dataset info to: `{initial_size_cats}`")
current_size_cats = state.get("size_categories") or ["unknown"]
ok, nonok = split_known(current_size_cats, known_size_categories)
if len(nonok) > 0:
leftcol.markdown(f"**Found bad codes in existing tagset**:\n{nonok}")
else:
state["size_categories"] = [initial_size_cats]
########################
## Show results
########################
rightcol.markdown(
f"""
### Finalized tag set
"""
)
if is_state_empty(state):
rightcol.markdown("❌ This is an invalid tagset: it's empty!")
else:
validate_dict(rightcol, state)
rightcol.markdown(
f"""
```yaml
{yaml.dump(state)}
```
---
#### Arbitrary yaml validator
This is a standalone tool, it is useful to check for errors on an existing tagset or modifying directly the text rather than the UI on the left.
""",
)
yamlblock = rightcol.text_area("Input your yaml here")
if yamlblock.strip() != "":
inputdict = yaml.safe_load(yamlblock)
validate_dict(rightcol, inputdict)
| datasets-tagging-main | tagging_app.py |
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