How does this compare against Dropbox's Lepton? Seems like any of these of image compression formats would make sense to support in archiving software like 7Zip, Winzip, Gzip, etc.
Lepton is a recompression format specifically for JPEG. It's lossless in the sense that you can reconstruct the input JPEG perfectly, but of course JPEG is itself an inherently lossy format.
FLIF is a lossless image format. It's not a good idea to give it an ex-JPEG file as input, just like it's not a good idea to convert JPEG to PNG, because it will need lots of bytes to losslessly compress all those JPEG artifacts that JPEG gets for free :).
