FLIF - Free Lossless Image Format

*DISCLAIMER: FLIF development has stopped since FLIF is superceded by FUIF and then again by [JPEG XL](https://jpeg.org/jpegxl/index.html), which is based on a combination of Pik and FUIF. A royalty-free and open source reference implementation of JPEG XL is available on [GitLab](https://gitlab.com/wg1/jpeg-xl).*
See the original notice here: https://github.com/FLIF-hub/FLIF/blob/master/README.md

FLIF is a lossless image format based on MANIAC compression.
MANIAC (Meta-Adaptive Near-zero Integer Arithmetic Coding)
is a variant of CABAC (context-adaptive binary arithmetic coding),
where the contexts are nodes of decision trees which are
dynamically learned at encode time.