Wanna compress discrete voxel data, without losing any of it? Here you go: https://www.reddit.com/r/VoxelGameDev/comments/9yu8qy/palettebased_compression_for_chunked_discrete/?
Working on GUI definitions... so far so good, but heckin ugly: https://media.discordapp.net/attachments/465128835885563924/513802445151797289/unknown.png
Damn, it turns out there is none... oh well, I've added one to my own format a long tim ago anyway, so consider the case closed (to heck with JSON).
The ability to freely translate, rotate, scale and skew the canvas one is drawing on would also be handy now and then...
Another thing I miss in image editors: Free Guidelines. Not just a plain old quadratic/isometric grid, but arbitrary patterns of lines that can be put above/below image-layers. Useful for perspective drawing.
Subimages and annotations that can be exported as, say, JSON... then it could even be used as a simple 2D map editor.
Full-stack programmer that loves cake, video games, computers, science and his family.