colorize-images.py

import numpy as np
import cv2


prototxt_path = 'models/colorization_deploy_v2.prototxt'
model_path = 'models/colorization_release_v2.caffemodel'
kernel_path = 'models/pts_in_hull.npy'
image_path = 'man.jpg' #targeted image


net = cv2.dnn.readNetFromCaffe(prototxt_path, model_path)
points = np.load(kernel_path)

points = points.transpose().reshape(2, 313, 1, 1)
net.getLayer(net.getLayerId("class8_ab")).blobs = [points.astype(np.float32)]
net.getLayer(net.getLayerId("conv8_313_rh")).blobs = [np.full([1, 313], 2.606, dtype="float32")]


bw_image = cv2.imread(image_path)
normalized = bw_image.astype("float32")/255.0
lab = cv2.cvtColor(normalized, cv2.COLOR_BGR2LAB)

resized = cv2.resize(lab, (244,244))
L = cv2.split(resized)[0]
L -= 50

net.setInput(cv2.dnn.blobFromImage(L))
ab = net.forward()[0, :, :, :].transpose((1,2,0))

ab = cv2.resize(ab, (bw_image.shape[1], bw_image.shape[0]))
L = cv2.split(lab)[0]

colorized = np.concatenate((L[:, :, np.newaxis], ab), axis=2)
colorized = cv2.cvtColor(colorized, cv2.COLOR_LAB2BGR)
colorized = (255*colorized).astype("uint8")

cv2.imshow("BW Image", bw_image)
cv2.imshow("Colorized", colorized)
cv2.waitKey(0)
cv2.destroyAllWindows()