1. A system for processing a multiband image, comprising: non-transitory digital computer memory for storing a multiband image having multiple bands of image data; and processing circuitry for processing the multiband image, wherein the processing circuitry (a) determines pixel locations in the bands of the multiband image having values meeting a corresponding band-specific value threshold for each of the bands of the multiband image, (b) determines a corresponding band-specific correction factor for each of the visible bands of the multiband image based on the determined pixel locations, and (c) applies the corresponding band-specific correction factor to the respective visible bands of the multiband image to produce a corrected image, wherein the values meet the corresponding band-specific value threshold if the values are above a corresponding band-specific white value threshold, wherein the corresponding band-specific correction factor is based on the largest average of values at least as large as the corresponding band-specific white value threshold value.