import numpy as np, cv2

bgr_img = cv2.imread("img/color_model.jpg", cv2.IMREAD_COLOR) # 컬러 영상 읽기

white = np.array([255, 255, 255], np.uint8)
cmy_img = white - bgr_img
cmy_channel = cv2.split(cmy_img) # 채널 분리

black = cv2.min(cmy_channel[0], cv2.min(cmy_channel[1], cmy_channel[2])) # 원소 간의 최솟값 저장
yellow, magenta, cyan = cmy_channel - black

titles = ['black','yellow','magenta','cyan']
[cv2.imshow(t, eval(t)) for t in titles]

cv2.waitKey(0)