[698969]

> a very popular format that gets EXTREMELY high compression ratios on bilevel images of types typical to scanned pdfs

Funny you say that, https://en.wikipedia.org/wiki/JBIG2#Character_substitution_e...

[cocodill]

I can still remember this cool talk about that. https://www.youtube.com/watch?v=7FeqF1-Z1g0