fix: load_image should support PIL Image

[Laisky]

What does this PR do?

load_image should support PIL.Image.

Fixes #6479 (comment)

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  • Remove conversion to RGB #6479
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[sayakpaul]

Wonder why would someone call load_image() on an already properly loaded image, though.

[Laisky]

Many tutorials are written like this😁, Perhaps to ensure things like RGB, or to ensure the consistency of types

[sayakpaul]

Hmm as per the method signature, it seems like load_image() should support a PIL image but the code below currently doesn't work:

from diffusers.utils import load_image 

image = load_image(image)

where image is a PIL image. I'd be in favor of this. @yiyixuxu WDYT?

[yiyixuxu]

@sayakpaul
yes we should add it back
I think this is in the original implementation anyway

[sayakpaul]

Alright. Feel free to merge once the CI is green.

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