Patent ID: 8351710

Claim:
A method for measuring similarity of two two-dimensional images, each comprised of pixels having intensity values and a useful signal that is to be used for comparing the two two-dimensional images, at least one image of the two two-dimensional images further comprising an additional signal having a direction gradient and a direction perpendicular to the direction gradient, the method comprising: partitioning the two two-dimensional images, respectively, into mutually corresponding subimages, wherein an extension of at least one subimage of said at least one image in the direction of the gradient of the additional signal is smaller than the extension of said at least one subimage in the direction perpendicular thereto, wherein the useful signal of said at least one image in the subimage changes in a characteristic and detectable manner, while the additional signal changes only slightlly, and wherein the subimages can be line-shaped or ring-shaped, comparing mutually associated subimages with one another; and combining the results of these comparisons into an overall measure of the similarity of the two images.