1. A computer-implemented method, comprising: creating JPEG quantization coefficients, by a computing system, for each respective color plane of a plurality of color planes; JPEG decoding each color plane, by the computing system, to generate YCbCr discrete cosine transform (DCT) coefficients for estimated spectrum adaptive postfilter (ESAP) postfiltering; ESAP postfiltering each of the color planes, by the computing system; and outputting a JPEG image file and an ESAP postfiltered image file, by the computing system.