Global motion parameter extraction and deformable block motion estimation

A global motion parameter estimation method is proposed. The method can be used to segment an image sequence into regions of different moving objects. For any tao pixels belonging to the same moving object, their associated g lobal motion components have a fixed relationship from the projection geome try of camera imaging. Therefore, by examining the measured motion vectors we are able to group pixels into objects and, at the same time, identify so me global motion information. In the presence of camera zoom, the object sh ape is distorted and conventional translational motion estimation may not y ield accurate motion modeling. A deformable block motion estimation scheme is thus proposed to estimate the local motion of an object in this situatio n. Some simulation results are reported. For an artificially generated sequ ence containing only zoom activity, we find that the maximum estimation err or in the zoom factor is about 2.8%. Rather good moving object segmentation results are obtained using the proposed object local motion estimation met hod after zoom extraction. The deformable block motion compensation is also Seen to outperform conventional translational block motion compensation fo r video material containing zoom activity.