At least based on the results shown in the paper (not that you should be taking that to be the norm …) this seems to give some great looking results The authors claim that people rated images generated by UPainting to be more visually pleasing than those generated by Stable Diffusion …
The difference in the approach (vs. Stable Diffusion) seems to be in using a text-image matching component. I’d be interested to try this approach out to see how well it performs in general scenarios.
The paper is here:
Here’s some sample output as mentioned in the paper itself (no code exists at the moment, so I can’t test it out myself):