Yeah, thats slow - but the approach is at least interesting:

I tried to compare it with other encoders for the sample (girl/face painting): https://show.quicky.club/results/14/f8/f1/d8db84d57222d32db6...

The PICO-result claim to achieve 0.268 bpp (bit-per-pixel): Even webp (version 1) can do that good enough.

I understand, that one needs really advanced hardware to decode this. Not sure if this is worth the hassle.