Hierarchical block motion estimation for video subband coding

In this paper, a new hierarchical motion estimation scheme is proposed for progressive video coding based on subband divisions. It is based on the hierarchical block matching for a pass- band pyramid, where each layer of image except the top-most layer has the pass-band image reconstituted by use of only three highpass subbands. Using this scheme, since the quantization error at a given layer exits at only the image of the layer, the coding performance can be improved by exact motion estimation. We also present a method to encode the residue (error frame) in the pyramid structure. It is found that the hierarchical block motion estimation based on the pass-band layers is better than the base-band layers, especially when the quantization is included through transmission.