banding artifacts in hires fix

Using hires makes vertical/horizontal banding artifects. I have tested with different hires upscalers some are less noticable, but it is visible depending on the image. Also it is more prominent if we use higher multiplier in hires. My example (on her face, click on full res to see):

You can read more about this issue here:
https://www.reddit.com/r/StableDiffusion/comments/1eyrljx/what_am_i_doing_that_is_causing_the_banding/

I'm not sure about the Tiled Diffusion possible solution though.

Start by reproducing the reported vertical and horizontal banding with hires using different upscalers and higher multipliers, referring to the attached full-resolution example. Read the linked Reddit discussion and investigate whether the mentioned Tiled Diffusion approach is relevant; done means identifying a reproducible cause and confirming that the artifacts are resolved.

Written by the indexing model from the issue text.