> But much more interesting to me is a lossless domain-specific compressor, which I’m not aware of any examples of. (Please tell me if about some if you know th

> But much more interesting to me is a lossless domain-specific compressor, which I’m not aware of any examples of. (Please tell me if about some if you know them!) A bit academic, but if you check out this paper from 2015 https://arxiv.org/pdf/1502.04623.pdf https://arxiv.org/pdf/1502.04623.pdf on a neural network trained on binarised MNIST (28x28 pixel images), Table 2 quotes entropy figures of 116.815 after converting to bits, which would be 28*28/116.815=6.71x compression (if used as a compressor)