Add workaround to prevent importing gradio breaking PIL.Image.registered_extensions()

[aliencaocao]

Description

This is a Pillow issue but the folks at Pillow suggested a workaround in python-pillow/Pillow#6809 (comment)
Until Pillow merges python-pillow/Pillow#6811 and publishes a new release (in Jan 2023 according to python-pillow/Pillow#6750), this would be the only way to fix it.

The issue is importing matplotlib.figure will in turn import PIL.PngInfoPlugin, which causes existing extensions to not be initialized fully but only initialized with PNG formats. Thus, Image.init() have to be called before this import.

Closes: #2843

Checklist:

• I have performed a self-review of my own code
• I have added a short summary of my change to the CHANGELOG.md
• My code follows the style guidelines of this project
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[aliencaocao]

All the failing tests are due to the use of Image.init() before importing matplotlib and others, however this is necessary for the fix

[abidlabs]

Thanks for the PR @aliencaocao! I tested it and it works for me. However, it also works for me if you move include the line PIL.Image.init() after all of the import statements (e.g. to line 67, right above set_documentation_group("component"))

Can you try this and see if it works for you as well? That way, we can satisfy the linter as well

[aliencaocao]

Hi thanks for pointing out. I tested and it indeed works. Already fixed my PR.

Although there are still failing tests indicated though not required

[abidlabs]

Thank you @aliencaocao for making the update! Don't worry about the flaky tests, they're not related to your code. If all of the other tests pass, I'll merge this in

[abidlabs]

Looks good! Thanks again @aliencaocao for the fix

[radarhere]

Pillow 9.4.0 has now been released

[aliencaocao]

gradio 3.15 is also released, that version already includes a fix