oh yeah like the paper says it's doing SAT a lot of times. Nearest I can tell the time complexity for each bit of the output is O(n!) where n is the size of the (unknown and you are solving for it) input bit pattern. So total time complexity is something like O(n! * w_n * h_n) which is BIG and stupid and might make this actually not a way to beat the optimum compression ratio dictated by entropy.