Multiresolution video compression: motion estimation and vector field coding

A multiresolution video coding scheme for very low bit rates is proposed, which is spatial scalable and thus allows easy adaptation to varying bandwidth conditions. Since the scheme is based on the hybrid coding principle it provides a low delay property making the codec well suited for communications applications. The frames to be coded are decomposed into a Gaussian-type pyramid. Motion estimation and compensation is performed between corresponding pyramid levels of successive frames such that the resulting prediction errors are close to a Gaussian pyramid decomposition of the prediction error at the highest resolution level. From this pyramid a Laplacian-type pyramid is derived and coded in an embedded fashion using conditioning contexts. The obtained motion vector fields at the different resolution levels form also a Laplacian-type pyramid which is encoded using zero-trees