ColorTransform.py

__author__ = 'Charlie'
import os, sys, inspect
import cv2
import numpy as np
import argparse

# Info:
# cmd_folder = os.path.dirname(os.path.abspath(__file__))
# __file__ fails if script is called in different ways on Windows
# __file__ fails if someone does os.chdir() before
# sys.argv[0] also fails because it doesn't not always contains the path
cmd_subfolder = os.path.realpath(os.path.abspath(os.path.join(os.path.split(inspect.getfile(inspect.currentframe()))[0],"..","Image_Lib")))
if cmd_subfolder not in sys.path:
    sys.path.insert(0, cmd_subfolder)

import image_utils as utils

ap = argparse.ArgumentParser()
ap.add_argument("-s", "--source", required = True, help = "Path to source image")
ap.add_argument("-t", "--target", required = True, help = "Path to target image")

args = vars(ap.parse_args())
source = cv2.cvtColor(cv2.imread(args["source"]), cv2.COLOR_BGR2LAB).astype("float32")
target = cv2.cvtColor(cv2.imread(args["target"]), cv2.COLOR_BGR2LAB).astype("float32")

(l, a, b) = cv2.split(source)
(srcLMean, srcLStd) = (l.mean(), l.std())
(srcAMean, srcAStd) = (a.mean(), a.std())
(srcBMean, srcBStd) = (b.mean(), b.std())

(l, a, b) = cv2.split(target)
(tarLMean, tarLStd) = (l.mean(), l.std())
(tarAMean, tarAStd) = (a.mean(), a.std())
(tarBMean, tarBStd) = (b.mean(), b.std())

#subtract mean value of image
l -= tarLMean
a -= tarAMean
b -= tarBMean

#scale std deviation based on source image
l *= (tarLStd/srcLStd)
a *= (tarAStd/srcAStd)
b *= (tarBStd/srcBStd)

#add source image mean to target
l += srcLMean
a += srcAMean
b += srcBMean

# clip the pixel intensities to [0, 255] if they fall outside
# this range
l = np.clip(l, 0, 255)
a = np.clip(a, 0, 255)
b = np.clip(b, 0, 255)

# merge the channels together and convert back to the RGB color
# space, being sure to utilize the 8-bit unsigned integer data
# type
transfer = cv2.merge([l, a, b])
transfer = cv2.cvtColor(transfer.astype("uint8"), cv2.COLOR_LAB2BGR)

cv2.imshow("Color Transform", utils.image_resize(transfer, height = 500))
cv2.waitKey()
cv2.destroyAllWindows()