1. A method of processing a digital image, comprising the steps of: a) assigning belief values to pixels in the digital image, wherein the belief values are proportional to a belief that the pixels are associated with human skin; b) calculating a brightness adjustment amount based on a statistic of the pixels with belief values exceeding a threshold and the assigned belief values of the pixels; and c) applying the brightness adjustment amount to the digital image to produce a processed digital image having improved overall brightness.