There are also ways to make files less entropic(Gray code):
applying repeatedly x^(x>>1) on the file integer representation, will produce a form with has least 1's vs 0's.
This form can be back-transformed to x, by recovering the pre-xor bits of each step(as it represents change of old bit to next bit).
https://en.wikipedia.org/wiki/Gray_code#Converting_to_and_from_Gray_code