farbfeld

farbfeld is a lossless image format which is easy to parse, pipe and
compress.
It has the following format:

| Bytes | Description |
|--------|------------------------------------------------------------|
| 8 | "farbfeld" magic value |
| 4 | 32-Bit BE unsigned integer (width) |
| 4 | 32-Bit BE unsigned integer (height) |
| [2222] | 4⋅16-Bit BE unsigned integers [RGBA] / pixel, row-aligned |

http://tools.suckless.org/farbfeld/

I like your image format. It's really clever to split image representation and compression into two different stages. Dijkstra taught us about the importance of seperation of concerns and this embodies that in a way that has genius simplicity.