I think it's nice to have a simple format for storing images for the sake of being able to build a pipeline of filters that are very lightweight and simple to implement.

But I was really distracted by how the author kept going on borderline nonsensical tangents about compression. There's a reason we usually build compression into the file format, instead of just zipping a lossless bitmap. It turns out that there's a ton of stuff you can do to exploit redundancy in two dimensions - if you can apply a transformation before the compression stage.

And yeah, you can make up some of your losses by using bzip2. But again, there's a reason formats like PNG don't do that: it's slow.