How to make OpenCv show an image in combination of two color channels?

Question

It\'s not that difficult to use OpenCV to get an output of one colour channel from an image and that can be easily done.

But is it possible that from the three main BGR

Answer 1

I guess one thing you could do is hold the channels separately and combine what you want for viewing:

#!/usr/local/bin/python3

import numpy as np
import cv2

im    = cv2.imread('sd71Z.jpg')
b,g,r = cv2.split(im)
zeros = np.zeros_like(b)

cv2.imshow("Zero blue",  cv2.merge([zeros,g,r]))
cv2.imshow("Zero green", cv2.merge([b,zeros,r]))
cv2.imshow('Zero red',   cv2.merge([b,g,zeros]))
cv2.waitKey()