摘要 |
<p>A technique for estimation of displacement and/or velocity of objects in television scenes is recursive, in that each displacement calculation is made using the results of the previous calculation. In a first embodiment, a displaced frame difference DFD (i.e., the intensity difference between a spatial location in the present video frame and a location in the previous frame displaced from that location by an initial displacement estimate) is updated using the initial value of DFD normalized by a measure of local picture activity. In a second embodiment, the update is a multiplicative function of DFD and the intensity gradient at the displaced location in the previous frame. </p> |