Example of inpaint doesn't work for Stable Diffusion 2.1

[Emulator000]

I'm trying the same example for the 2.1 configuration, downloaded the appropriate CLIP, UNET and VAE and converted them correctly but it does not seems to work.

Command:

cargo run --example stable-diffusion-inpaint --features clap -- --sd-version="v2-1" --prompt "Face of a yellow cat, high resolution, sitting on a park bench." --input-image="temp/dog.png" --mask-image="temp/dog_mask.png" --width=512 --height=512

This is the output that i get with the dog/cat example that works perfectly with Stable Diffusion 1.5:

It seems that the inpainted area doensn't correctly populate.

Any possible reason for that? Should the example/code be adapted for some additional steps for the 2.1 version?

[LaurentMazare]

No clue what is going on here, I also tried it and got the same results using the weights from stabilityai/stable-diffusion-2-inpainting. I also tried the native resolution of 768x768 without luck. Spotting the json config files for the different versions, I haven't noticed anything that would obviously require some adaptation. I guess at this point the simpler would likely be to run the inpainting process on the Python and Rust side and see at which layer things start to diverge.

[LaurentMazare]

Ah it seems that actually one difference was that the scheduler for stable-diffusion 2.1 uses a prediction type of v_prediction in normal generation but uses a prediction type of epsilon for inpainting (whereas stable-diffusion 1.5 uses epsilon for both). I've just merged a PR #63 that should hopefully help with this - at least on a single generated image it looks better now.

There is still a scheduler inconsistency as we use DDIM rather than PNDM - also using a proper DPM solver would likely help here but hopefully this doesn't make much of a difference. Please give a spin to the current github tip if you can and let us know how it gets.