>>1988839>FLIF will never get there, its advantage over PNG is marginalNo. FLIF blows a PNG you've invested 40+ minutes and billions of cycles into optimizing, right out of the water, usually in under 5 - 10 seconds, if not instantly. Even if you have very fast and accurate heuristics for scanline filter selection, generating a decent DEFLATE stream takes time and trials of a number of methods. It's often hard to know which will converge the best.
Every system has an absolute minimum size required to represent a given set of information. I've found very few cases where a png (that's been practically brute forced), has been able to beat FLIF. Like I said above though, single frame GIFs are rarely capable of better compression than PNG. The script I made has a switch to try both when it receives such a gif, and in almost all cases, the PNG is better (relative to gifsicle -O3).
