Patent ID: 7095786

Claim:
An object tracker comprising: a motion estimator, receiving an object location in a base frame, for generating motion vectors representing displacements from regions in a current frame to best-matching regions in the base frame; a motion averager, receiving motion vectors from the motion estimator for regions that match best-matching regions that are within the object location in the base frame, for generating an average object motion from motion vectors for regions matching best-matching regions that are within the object location but excluding motion vectors for regions matching best-matching regions that are outside the object location or not entirely within the object location when generating the average object motion; a motion thresholder, receiving the average object motion from the motion averager, for comparing the average object motion to a motion threshold and adjusting a frame skipping parameter to skip frames between the base frame and the current frame when the average object motion exceeds the motion threshold, but not skipping frames and processing sequential frames when the average object motion is below the motion threshold; an adaptive region-size motion estimator, for sub-dividing regions in the base frame into sub-regions for regions matching best-matching regions that are partially within the object location, for generating motion vectors representing displacements from sub-regions in the current frame to best-matching sub-regions in the base frame; and an object-location generator, coupled to the adaptive region-size motion estimator, for generating a current object location for the current frame by including regions matching best-matching regions that are within the object location and including sub-regions matching best-matching sub-regions that are within the object location, whereby frame skipping is modulated based on motion of regions matching within the object location and whereby adaptive region-size matching along a boundary of the object location in the base frame refines the object location in the current frame.