Colorize_images / src /utils.py
Uzaiir's picture
Update src/utils.py
b8ee177 verified
import numpy as np
import cv2
from PIL import Image
import os
def convert_to_bw(image):
"""
Converts a PIL image to black & white (grayscale),
and then back to RGB to maintain compatibility with other processes.
Parameters:
image (PIL.Image): Input RGB image.
Returns:
PIL.Image: Black & white image in RGB format.
"""
return image.convert("L").convert("RGB")
def load_colorization_model():
"""
Loads the pre-trained Caffe model for colorizing black & white images.
Model files required:
- colorization_deploy_v2.prototxt
- colorization_release_v2.caffemodel
- pts_in_hull.npy
Returns:
cv2.dnn_Net: Loaded and initialized OpenCV DNN colorization model.
"""
# Paths to model architecture, weights, and cluster centers
base_path = os.path.join(os.path.dirname(__file__), "models")
# proto_file = "models/colorization_deploy_v2.prototxt"
# model_file = "models/colorization_release_v2.caffemodel"
# cluster_file = "models/pts_in_hull.npy"
proto_file = os.path.join(base_path, "colorization_deploy_v2.prototxt")
model_file = os.path.join(base_path, "colorization_release_v2.caffemodel")
cluster_file = os.path.join(base_path, "pts_in_hull.npy")
# Load the model using OpenCV DNN module
net = cv2.dnn.readNetFromCaffe(proto_file, model_file)
pts = np.load(cluster_file)
# Populate cluster centers as 1x1 convolution kernel
class8_ab = net.getLayerId("class8_ab")
conv8_313_rh = net.getLayerId("conv8_313_rh")
pts = pts.transpose().reshape(2, 313, 1, 1)
net.getLayer(class8_ab).blobs = [pts.astype(np.float32)]
net.getLayer(conv8_313_rh).blobs = [np.full([1, 313], 2.606, dtype=np.float32)]
return net
def colorize_bw_image(pil_img, net):
"""
Colorizes a grayscale (black & white) image using a pre-trained DNN model.
Parameters:
pil_img (PIL.Image): Input grayscale image in RGB format.
net (cv2.dnn_Net): Loaded OpenCV DNN colorization model.
Returns:
PIL.Image: Colorized image in RGB format.
"""
# Convert PIL image to NumPy array
img = np.array(pil_img)
img_rgb = img[:, :, [2, 1, 0]] # Convert RGB to BGR
img_rgb = img_rgb.astype("float32") / 255.0
# Convert to LAB color space and extract L channel
img_lab = cv2.cvtColor(img_rgb, cv2.COLOR_BGR2LAB)
l_channel = img_lab[:, :, 0]
# Resize L channel to match model input size and normalize
input_l = cv2.resize(l_channel, (224, 224))
input_l -= 50
# Run inference
net.setInput(cv2.dnn.blobFromImage(input_l))
ab_channels = net.forward()[0, :, :, :].transpose((1, 2, 0)) # shape: (56, 56, 2)
# Resize predicted ab channels to match original image size
ab_channels = cv2.resize(ab_channels, (img.shape[1], img.shape[0]))
# Merge original L channel with predicted ab channels
lab_output = np.concatenate((l_channel[:, :, np.newaxis], ab_channels), axis=2)
# Convert LAB to BGR, clip values, and convert to uint8
bgr_out = cv2.cvtColor(lab_output, cv2.COLOR_LAB2BGR)
bgr_out = np.clip(bgr_out, 0, 1)
# Convert back to RGB and return as PIL Image
final_rgb = (bgr_out[:, :, [2, 1, 0]] * 255).astype("uint8")
return Image.fromarray(final_rgb)