Patent ID: 6738424
Filing Date: 2004-05-18
Classification: G06T,H04N

Abstract:
A method of generating and utilizing a three-dimensional cube-based scene model from a sequence of video frames, comprising the steps of:separating background data from foreground data for each of said frames; using an estimate of relative observer motion, projecting each frame onto a coordinate system used in generating said scene model; merging the background data of the frame with the scene model; detecting whether or not a current focal length in a frame has changed relative to a previous focal length of a previous frame, comprising the sub-steps of: choosing a point on the right edge of a frame; converting said point to cube coordinates; choosing a corresponding point on the left edge of said frame, said corresponding point having a row coordinate in common with said point on the right edge of the frame; converting said corresponding point to cube coordinates; determining the size of an angle between vectors formed by connecting said points converted to cube coordinates with the origin of said cube coordinates; and if said angle differs from that corresponding to said previous frame in an amount exceeding a particular value, determining that the focal length has changed; and if said detecting step determines that the focal length has changed, creating a new scene model layer corresponding to the current focal length.