1. An automated, computerized method for processing an image, comprising the steps of: providing an image file depicting an image defined by image locations, in a computer memory; generating a bi-illuminant chromaticity plane in a log color space for representing the image locations of the image in a log-chromaticity representation for the image; providing an estimate for an orientation of the bi-illuminant chromaticity plane; and optimizing the estimate of an orientation as a function of a minimization of a weighted entropy.