I don't know if the author is rediscovering or inspired by lossless image compression algorithms. For example PNG has a palette mode that supports up to 256 col

I don't know if the author is rediscovering or inspired by lossless image compression algorithms. For example PNG has a palette mode that supports up to 256 colors in the palette. And of course so does GIF. The run-length-encoding is probably just a primitive version of LZW. I wonder if it might be better to simply use PNG with an extra chunk for the UUID and timestamp information.