Patent ID: 8548237

Claim:
A method, comprising, for each of multiple local image patches identified in an image comprising image forming elements: dividing the local image patch into respective sub-patches of respective ones of the image forming elements; for each of the respective image forming elements in the local image patch, determining a respective ordinal rank of the image forming element, wherein each ordinal rank corresponds to a respective dimension of an ordinal rank feature space, and ascertaining respective contributions of the image forming element to a particular one of the respective sub-patches containing the image forming element and to one or more other ones of the respective sub-patches neighboring the particular sub-patch; for each of the respective sub-patches of the local image patch, building a respective histogram of ascertained contributions of the image forming elements in the ordinal rank feature space; and generating a respective feature vector representing the local image patch from the respective histograms built for the sub-patches of the local image; wherein the dividing, the determining, the ascertaining, the building, and the generating are performed by a processor.