| import torch | |
| import torch.nn as nn | |
| import torch.nn.functional as F | |
| from ldm.modules.diffusionmodules.model import Encoder, Decoder | |
| from ldm.modules.distributions.distributions import DiagonalGaussianDistribution | |
| from ldm.util import instantiate_from_config | |
| class AutoencoderKL(nn.Module): | |
| def __init__(self, | |
| ddconfig, | |
| embed_dim, | |
| ckpt_path=None, | |
| ignore_keys=[], | |
| image_key="image", | |
| colorize_nlabels=None, | |
| monitor=None, | |
| ): | |
| super().__init__() | |
| self.image_key = image_key | |
| self.encoder = Encoder(**ddconfig) | |
| self.decoder = Decoder(**ddconfig) | |
| assert ddconfig["double_z"] | |
| self.quant_conv = torch.nn.Conv2d(2*ddconfig["z_channels"], 2*embed_dim, 1) | |
| self.post_quant_conv = torch.nn.Conv2d(embed_dim, ddconfig["z_channels"], 1) | |
| self.embed_dim = embed_dim | |
| if colorize_nlabels is not None: | |
| assert type(colorize_nlabels)==int | |
| self.register_buffer("colorize", torch.randn(3, colorize_nlabels, 1, 1)) | |
| if monitor is not None: | |
| self.monitor = monitor | |
| if ckpt_path is not None: | |
| self.init_from_ckpt(ckpt_path, ignore_keys=ignore_keys) | |
| def init_from_ckpt(self, path, ignore_keys=list()): | |
| sd = torch.load(path, map_location="cpu")["state_dict"] | |
| keys = list(sd.keys()) | |
| for k in keys: | |
| for ik in ignore_keys: | |
| if k.startswith(ik): | |
| print("Deleting key {} from state_dict.".format(k)) | |
| del sd[k] | |
| self.load_state_dict(sd, strict=False) | |
| print(f"Restored from {path}") | |
| def encode(self, x): | |
| h = self.encoder(x) | |
| moments = self.quant_conv(h) | |
| posterior = DiagonalGaussianDistribution(moments) | |
| return posterior | |
| def decode(self, z): | |
| z = self.post_quant_conv(z) | |
| dec = self.decoder(z) | |
| return dec | |
| def forward(self, input, sample_posterior=True): | |
| posterior = self.encode(input) | |
| if sample_posterior: | |
| z = posterior.sample() | |
| else: | |
| z = posterior.mode() | |
| dec = self.decode(z) | |
| return dec, posterior |