1. A method for compressing an input image, comprising: (a) determining a plurality of entropy code sets based upon statistically similar regions in the input image; (b) generating a sub-resolution image, wherein each pixel in the sub-resolution image stores an entropy code set from the plurality of entropy code sets, the entropy code set encoding corresponding pixels in the input image; (c) encoding the input image using the generated sub-resolution image to control a compression parameter including an entropy code; and (d) outputting the encoded input image and the generated sub-resolution image as a compressed entropy coded image file.