I've been working on this tool again from time to time and I just added billinear filter. Using it alongside with some sharpening filter I was able to improve a low resolution picture.

There's other algorithms that I still want to implement and maybe refactor the UI a bit, but overall I'm quite happy with my toy editor.

I found this neat website with this cool algorithm to erase pieces of a image called darn (darn it) and I just implemented that on my editor as well.

https://wordsandbuttons.online/image_darning.html

I have just recorded a video about darn it and the bilinear filter

https://www.youtube.com/watch?v=EpiCLEMfgPs