[SDXL Inpaint] Correct strength default

[patrickvonplaten]

What does this PR do?

SDXL inpainting rarely works well with strength=1.0 which surprises many users. The default was copied from SD v1-5. This PR changes the default to 0.9999, to make sure at least some part of the original image is kept in the masked area.

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint.

[JohanHuynh0130]

hi @patrickvonplaten , thanks for fixing this issue it took me a while to figure it out. However, changing the strength to 0.9999 somehow also change the color grading or (Adding grain?) to the final output. Here are some of the example:

Photo to be inpainted:

Mask:

Some of the result:

For the non-masked, the image stays the same but you can see it has a weird grading onto it. Or maybe it's because of my resize function (basic PIL resize)

[patrickvonplaten]

Hmm you don't have this when using strength=1.0? Maybe it's also the watermarker that causes these red/green dots

[YQYI]

this change makes my result totally different........, it tooks me a while to fix that.....

[garychan22]

@YQYI how do you fix it, using strength = 0.9999?