[bug]: Tiled decoding ruins the image

[seinan9]

[bug]: Tiled decoding ruins the image

[psychedelicious]

The handling of tiled decode hasn't changed in some time - several months. This functionality is handled wholly by diffusers, and it appears their implementation also hasn't changed in months.

It's possible there was some change in another area of diffusers or invoke that indirectly affect how tiled decoding is handled.

However, slight changes like this are known effects of tiled decoding. The model doesn't have the full context of the image, it's expected that the tiled decode has measurable and sometimes visual differences. There's some discussion here, though the example images appear to be missing now.

A more convincing comparison would be between a v3.7.0 image with tiled decode vs v4 image with tiled decode (no upscaling please, that adds another variable to the equation). Ideally a few comparisons.

[seinan9]

It is less visible during the first pass, since there is typically only a single tile (2 at most if the resolution is set a bit higher). Still here are two more example without upscaling (512x768). Images 1 and 3 were generated via InvokeAI 3.7, while 2 and 4 were generated using InvokeAI 4.0.2. Same parameters for alle images.

[psychedelicious]

Thanks for those examples. It's still very noticeable. I think we need to test this with diffusers (i.e. via separate script, not within invoke) to confirm where the problem is.

[seinan9]

Your welcome. And thank you for looking into it!