Sometimes things aren't "bad" per se, they just aren't as good.

Wavelets seem to be another perennial also-ran in the image compression space. They work. They have the odd useful property here and there. They just aren't as good for most purposes.

There can also be differences in terms of investment; if hypothetically there were 3 techniques with roughly equally-useful "final forms", but only one of them gets that investment, then it'll win because there's no reason to pour the additional effort into the other two.

a slow to compress format that does a good job sounds great for physical media which gets distributed, but sounds like it would be bad where the things being compressed are most probably many millions of individual images uploaded by users as you want a fast enough compression that you can start to return the compressed image to the user within milliseconds.

That just sounds to me like what happened to it, although I can't say for sure - did it perhaps also have other things about it that would make it a problem to be running lots of concurrent fractal compressing processes on a server?

I don't know - the machine I played with it on was a 16MHz 386, and the IFS software was not optimized. But it was way slower than DCT-based JPEGs to compress.

The odd thing about it though, was that it could upscale smoothly. A 320x200 source could be decompressed at 640x400, and it would sort of intelligently "fill in the gaps" on textures etc.

Some comparison between fractal compression and jpeg here: https://dl.acm.org/doi/fullHtml/10.5555/364682.364685

Slow to compress in the 1990s is probably not that slow to compress in 2024.

And you can always do fast initial compression on images needed immediately, and run background compression to replace them with the smaller versions.

hmm, yeah I never thought about that (the second part)

but slow to compress is always relative to fast to compress, and fast is related to user expectations of speed which is calibrated to your competitor's speed, thus if something is slow to compress it will probably stay slow to compress even as its speed increases.

> I don't know what happened to it.

From what I've heard, licensing costs were significant.

Presumably the patents are all expired now?

I think they were patented in the early 90s which would mean they've expired by now, yeah. CPUs and whatnot these days would make compression faster but trying to convince people to switch to fractal compression now is undoubtedly a losing proposition.