Image Number 7 for United States Patent #8121424.
A system, computer program product and associated methodology for video motion detection combines a series of images of a video sequence into an image volume having vertices of X, Y and t. The image volume is sliced in either the (X,t) or (Y,t) planes, filtered with a spatio-temporal filter and thresholded to reduce the amount of information. Then a search algorithm searches along search lines in a subset of the video sequence to locate motion. Motion can be detected by identifying lines that are not parallel to any of the vertices. Stationary subjects and lighting changes appear as lines parallel to one of the vertices. Thus, true motion can be distinguished from lighting changes.