Computing the difference between two images

The following code returns the absolute value of the pixel-by-pixel difference between images. Image difference can be used to detect changes between two images. For example, the next code block shows how to compute the difference image from two successive frames from a video recording (from YouTube) of a match from the 2018 FIFA World Cup:

from PIL.ImageChops import subtract, multiply, screen, difference, add
im1 = Image.open("../images/goal1.png") # load two consecutive frame images from the video
im2 = Image.open("../images/goal2.png")
im = difference(im1, im2)
im.save("../images/goal_diff.png")

plt.subplot(311)
plt.imshow(im1)
plt.axis('off')
plt.subplot(312)
plt.imshow(im2)
plt.axis('off')
plt.subplot(313)
plt.imshow(im), plt.axis('off')
plt.show()

The next figure shows the output of the code, with the consecutive frame images followed by their difference image: