ValueError: images do not match

[alanhamlett]

Without changing code, only upgrading from 10.1.0 to 10.2.0, started getting this error when generating animated GIFs:

  File "wakatime/insights/utils.py", line 481, in get_animated_insight
    images[0].save(out, format="gif", append_images=images[1:-1], save_all=True, duration=80, loop=0)
  File "venv/lib/python3.10/site-packages/PIL/Image.py", line 2439, in save
    save_handler(self, fp, filename)
  File "venv/lib/python3.10/site-packages/PIL/GifImagePlugin.py", line 704, in _save_all
    _save(im, fp, filename, save_all=True)
  File "venv/lib/python3.10/site-packages/PIL/GifImagePlugin.py", line 715, in _save
    if not save_all or not _write_multiple_frames(im, fp, palette):
  File "venv/lib/python3.10/site-packages/PIL/GifImagePlugin.py", line 671, in _write_multiple_frames
    diff_frame.paste(fill, mask=ImageOps.invert(mask))
  File "venv/lib/python3.10/site-packages/PIL/Image.py", line 1738, in paste
    self.im.paste(im, box, mask.im)
ValueError: images do not match

• OS: Linux
• Python: Python 3.10.12
• Pillow: pillow==10.2.0

[hugovk]

Thank you for reporting an issue.

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• https://stackoverflow.com/help/mcve

Bug reports which follow these guidelines are easier to diagnose, and are often handled much more quickly.

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[alanhamlett]

Looks like this commit is the culprit: 55c5587

[radarhere]

Yes, that would be the cause - but rather than just undoing that change, it would be better to adjust it, to both reduce filesize and to fix your problem. The quickest way of understanding how to do that would be for you to post a self-contained example of your problem.

[alanhamlett]

Here's a repo to reproduce the bug:
https://github.com/alanhamlett/pillow-issue-7777

[radarhere]

Thanks.

0.png, 4.png and 5.png are 120px wide.
1.png, 2.png and 3.png are 108px wide.

The images you are using to create your GIF are not all the same size. So, as error says, the images do not match.

If you change them to all be the same size, the error goes away.

[alanhamlett]

Got it, so it should have raised that exception in previous versions too. Thanks!

[alanhamlett]

Actually, looks like animated GIF format supports images of different sizes. Should Pillow also?

[radarhere]

I've created PR #7779 to resolve this.