US Patent 7388987 Computing dissimilarity measures

Methods, machines, and machine-readable media for computing dissimilarity measures are described. In one aspect, a first set of pixel neighborhood values (PNVs) is computed from respective sets of pixel values of a first image corresponding to different spatially-shifted pixel neighborhoods each encompassing a mutual target pixel in the first image. A second set of PNVs is computed from respective sets of pixel values of a second image corresponding to different spatially-shifted pixel neighborhoods each encompassing a mutual target pixel in the second image. A measure of dissimilarity is computed based at least in part on the first and second sets of computed PNVs. The computed dissimilarity measure is stored on a machine-readable medium.