[python] Remove one color channel & Save

import cv2

import numpy as np

# read image into matrix.

m =  cv2.imread("python.png")

# get image properties.

h,w,bpp = np.shape(m)

# iterate over the entire image.

for py in range(0,h):

    for px in range(0,w):

        m[py][px][0] = 0

# display image

cv2.imshow('matrix', m)

cv2.waitKey(0)

cv2.imwrite('filename.png',m)