Precision reduced to 2-bits, with "codebook" of 2 within each 4x4 patch. Similar to https://en.wikipedia.org/wiki/Block_Truncation_Coding https://en.wikipedia.o

Precision reduced to 2-bits, with "codebook" of 2 within each 4x4 patch. Similar to https://en.wikipedia.org/wiki/Block_Truncation_Coding https://en.wikipedia.org/wiki/Block_Truncation_Coding but use 1 more bit. There are a lot of tuning left to do to find better ways to encode that reduces MSE.