Python PILLOW Can't compare two images correctly

Question

I want to compare two images and then decide whether they are the same or not but the PIL library is not able to tell me the correct result. Even I use both ways to compare them it returns true for two different grayscale images.

difference = ImageChops.difference(image1.convert('L'), image2.convert('L'))
if not difference.getbbox() and list(image1.convert('L').getdata()) == list(image2.convert('L').getdata()):

I am using it in this manner but I couldn't handle this problem.

These are the example images for that situation:

Please share the two images you compared and show the difference image. — Mark Setchell, Jan 08 '22 at 16:04

score 4 · Answer 1 · answered Jan 08 '22 at 18:11

4

Your images have got a superfluous alpha channel. It appears to work if you discard that.

#!/usr/bin/env python3

from PIL import Image, ImageChops

im1 = Image.open('LQk4R.png').convert('L')
im2 = Image.open('gKx4l.png').convert('L')

diff = ImageChops.difference(im1,im2)
diff.show()

In IPython:

In [13]: diff.getbbox() 
Out[13]: (0, 0, 220, 63)

In [14]: im1.getdata() == im2.getdata()
False

answered Jan 08 '22 at 18:11

Mark Setchell

191,897
31
273
432

Sometimes it works but sometimes still doesn't work. But I solved it by another way of doing this process. – ghostcasper Feb 15 '22 at 21:21

Python PILLOW Can't compare two images correctly

1 Answers1