Patent ID: 8665375

Claim:
In a sequence of video fields having a foreground component and a background component, an apparatus for tracking a pointing device in use by a foreground subject which device is the leftmost or rightmost object within the foreground component, comprising: a control circuit configured to: a) determine the boundaries of a cropped video field within each of the video fields; b) determine for each cropped video field a pixel value and scan line representing the leftmost position of the foreground subject and pointing device for that cropped video field and a pixel value and scan line representing the rightmost position of the foreground subject and pointing device for that cropped video field; c) determine the centerline of the foreground subject for each cropped video field; d) use the centerline for determining whether the pointing device is on the right side of the cropped video field or the left side of the cropped video field; and e) store the position of the pointing device after receipt of a signal generated by the foreground subject, wherein the boundaries of the cropped video field are determined by locating the largest contiguous block of pixels having a uniform color.