show lab color space

rubiks_lab.py

import cv2


def thresh(src, img, low, ty):
    _, mask = cv2.threshold(img, low, 256, ty)
    splits = [cv2.bitwise_and(x, mask) for x in cv2.split(src)]
    return cv2.merge(splits)


img = cv2.imread("rubiks.png")
lab = cv2.cvtColor(img, cv2.COLOR_BGR2LAB)
grey = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
[l, a, b] = cv2.split(lab)

def f(img):
    return cv2.resize(img, (200, 200))

while True:
    cv2.imshow("bgr", f(img))
    cv2.imshow("grey", f(grey))

    cv2.imshow("b max", f(thresh(img, b, b.max()-10, cv2.THRESH_BINARY)))
    cv2.imshow("a max", f(thresh(img, a, a.max()-10, cv2.THRESH_BINARY)))
    cv2.imshow("b min", f(thresh(img, b, a.min() + 10, cv2.THRESH_BINARY_INV)))
    cv2.imshow("a min", f(thresh(img, a, b.min() + 10, cv2.THRESH_BINARY_INV)))

    cv2.imshow("L", f(l))
    cv2.imshow("a", f(a))
    cv2.imshow("b", f(b))
    if cv2.waitKey(1) == ord('q'):
        break