Patent ID: 7650016

Claim:
A method for tracking motion of an object image, comprising: receiving an input image; correlating, in a computing system, the input image with a reference image, the correlating comprising: defining a search area of the input image; moving the reference image around the search area; computing a sum of differences between the input image and the reference image; and producing a reference image metric surface using multiple summations computed for multiple locations of the reference image relative to the search area of the input image; deriving multiple subimages from the input image; comparing each subimage with a subimage reference computing, in the computing system, a subimage metric surface for each subimage based on the comparing; computing, in the computing system, at least one peak for each subimage metric surface, respectively; computing, in the computing system, at least one peak for the reference image metric surface; computing, in the computing system, a motion vector for each subimage metric surface based on a result of a comparison of the at least one peak for the reference image metric surface with the computed at least one peak for each subimage metric surface, respectively; computing, in the computing system, a motion vector for the reference image metric surface using the computed at least one peak for the reference image metric surface; and outputting, from the computing system, a tracking assessment of object image motion based on the computed motion vector for each subimage metric surface, respectively, and the computed motion vector for the reference image metric surface.