[New Feature] Inpaint without changing unmasked area is implemented

[lllyasviel]

After many reports about inpaint, we fixed the codes so that the gradio code becomes consistent to SOTA implementation of A1111 - it will not change unmasked areas anymore.

Before fix:

After fix:

You can see the color offsets on the cloth disappear. Now the unmasked area is 100% same with input images.

[lllyasviel]

Note that A1111 users can ignore this since A1111 controlnet already had this - see also https://github.com/Mikubill/sd-webui-controlnet/discussions/1143

[Alexadar]

Works fantastic thanks! How can I speed it up, besides xformers?

[darshats]

Hi, Thanks for the great work. I am curious about this line in the gradio inpaint.py line 89:

    x_samples = x_samples * mask_pixel_batched + img_pixel_batched * (1.0 - mask_pixel_batched)

If this line is not there, I observe that text in the unmasked area gets garbled. By overlaying the area outside the mask it is restored. So then this could have been done earlier implementation too. I'm missing something as the commit for this change does push the mask deeper into the sampler. Could you help understand the change, and why overlay is needed? thanks!