Free Lossless Image Format

Sounds almost too good to be true... any major downside, other than current lack of support?

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This is really interesting! There seems to be some additional technical information here:

https://boards.openpandora.org/topic/18485-free-lossless-ima...

  - for interlacing it uses a generalization of PNG's Adam7; unlike PNG, the geometry of the 2D interlacing is exploited heavily to get better pixel estimation, which means the overhead of interlacing is small (vs simple scanline encoding, which has the benefit of locality so usually compresses better)

  - the colorspace is a lossless simplified variant of YIQ, alpha and Y channel are encoded first, chroma channels later

  - the real innovation is in the way the contexts are defined for the arithmetic coding: during encoding, a decision tree is constructed (a description of which is encoded in the compressed stream) which is a way to dynamically adapt the CABAC contexts to the specific encoded image. We have called this method "MANIAC", which is a backronym for "Meta-Adaptive Near-zero Integer Arithmetic Coding".

Perhaps the MANIAC/CABAC decoding or encoding is computationally more intensive compared to the others? Concerning lack of support, just like with the BPG decoder you could generate the Javascript through Emscripten so any javaszcript enabled browser can view them. Personally an even more efficient lossy image compressor would be great (getting my avatar down to 1K and still sharp). When using diagrams or text the mozjpeg artifact eraser is adequate.

Where are the images to compare? Bellard has a very neat demonstration on his page http://xooyoozoo.github.io/yolo-octo-bugfixes/#nymph&jpg=s&b...

BTW, credit to the flif people for linking competitor formats bpg and webP