I remember a proprietary image format (complete with a proprietary converter and viewer for Windows) in the 1990s that dubbed itself a "fractal compression algo

I remember a proprietary image format (complete with a proprietary converter and viewer for Windows) in the 1990s that dubbed itself a "fractal compression algorithm" -- and did an impressive job with things like water ripples in rivers or grassy terrain. You could "zoom in" 8-10X in an original nature photograph and be semi-convinced.