Answer by Moshe for How do I find an image contained within an image?

For anyone who stumbles across this in the future.

This can be done with template matching. To summarize (my understanding), template matching looks for an exact match of one image within another image.

Here's an example of how to do it within Python:

import cv2method = cv2.TM_SQDIFF_NORMED# Read the images from the filesmall_image = cv2.imread('small_image.png')large_image = cv2.imread('large_image.jpeg')result = cv2.matchTemplate(small_image, large_image, method)# We want the minimum squared differencemn,_,mnLoc,_ = cv2.minMaxLoc(result)# Draw the rectangle:# Extract the coordinates of our best matchMPx,MPy = mnLoc# Step 2: Get the size of the template. This is the same size as the match.trows,tcols = small_image.shape[:2]# Step 3: Draw the rectangle on large_imagecv2.rectangle(large_image, (MPx,MPy),(MPx+tcols,MPy+trows),(0,0,255),2)# Display the original image with the rectangle around the match.cv2.imshow('output',large_image)# The image is only displayed if we call thiscv2.waitKey(0)