[homm]

The simple question: if all the existing formats already solve the image compression problem, why a new image formats (WebP, HEIC, AVIF, JPEG XL etc) appears?

[mceachen]

As computers generally get faster, more expensive encoding can be considered.

I'm using different tooling on an AMD 3900x for these conversions, so take these numbers with a grain of salt.

    $ gm identify test.tiff
    test.tiff TIFF 6240x4160+0+0 DirectClass 8-bit 1.2Mi 0.000u 0m:0.000001s

    $ time gm convert test.tiff test.jpg

    real 0m0.282s
    user 0m0.193s
    sys 0m0.089s

    $ time heif-enc test.jpg -o test.heif

    real 0m1.901s
    user 0m22.960s
    sys 0m0.180s

So... that's literally 100x more CPU time to encode the HEIF than the JPEG. The JPEG is 1.1M, and the HEIF is 800K.

In my prior tests AV1 is 2-5x slower than HEIF, and JPEG-XL is ~10x slower.