OpenCV - Intersection between two binary images

Question

Let's say I have two binary images of the same size. How do I find the intersection between the two binary images? Only pixels of the same coordinate (location) on the two images that are white (gray - 255) will give white pixels on the output image (intersection).

Answer 1

You can use cvAnd or cv::bitwise_and on the two images. The resulting image will be white only where both the input images are white.

EDIT: Here are the results of applying cv::bitwise_and, cv::bitwise_or and cv::bitwise_xor on binary images:

These are the two source images:

Here is the result of applying cv::bitwise_and:

Here is the result of applying cv::bitwise_or:

Here is the result of applying cv::bitwise_xor:

Answer 2

Here's how to do this in python (with the images above):

import cv2  img1 = cv2.imread('black_top_right_triangle.png',0) img2 = cv2.imread('black_bottom_right_triangle.png',0)  img_bwa = cv2.bitwise_and(img1,img2) img_bwo = cv2.bitwise_or(img1,img2) img_bwx = cv2.bitwise_xor(img1,img2)  cv2.imshow("Bitwise AND of Image 1 and 2", img_bwa) cv2.imshow("Bitwise OR of Image 1 and 2", img_bwo) cv2.imshow("Bitwise XOR of Image 1 and 2", img_bwx) cv2.waitKey(0) cv2.destroyAllWindows() 

If you need to install OpenCV for Python, save time by following these directions (installation has historically been quite a pain).