Block grouping algorithm for motion description encoding

We present a method for improving the overall quality of motion compensated video codecs by using a variable number of motion objects to alter the bandwidth allocated to the motion description. The proposed algorithm takes as its input an existing motion vector field from which it extracts groups of vectors. Control is obtained by only encoding the largest N of these groups. Those blocks which do not belong to the N groups are reassigned to one based upon a block comparison metric. The resulting list of vectors and a mapping showing group membership are then entropy encoded. Experimental results demonstrate that by choosing a value of N that matches the type and complexity of motion in the sequence, the overall compression performance is improved