Fully scalable video compression with sample-adaptive lifting and overlapped block motion

Abstract

Motion compensated temporal lifting is a highly effective means for exploiting motion in wavelet-based video compression algorithms. One way to achieve both spatial and temporal scalability attributes is to apply a conventional spatial DWT to an initial set of temporal subbands. This t+2D paradigm may be reversed, performing the spatial transform first and temporally transforming its spatial subbands. In this paper, we show how the two paradigms can be bridged by a family of motion compensation operators. Different members of this family have different implications for compression efficiency and for artifacts which can appear at reduced resolutions. We show how the vector motion compensation operators can be adaptively selected so as to achieve high compression efficiency, while simultaneously suppressing artifacts which might otherwise occur during scaling. The vector motion compensation paradigm provides an efficient framework for in-band block-based motion modeling, which suppresses the appearance of blocking artifacts. The proposed adaptive motion compensation operators have an added advantage in automatically selecting between different resolution-dependent motion models, so as to maximize energy compaction while avoiding the appearance of artifacts at reduced resolutions. Resolution-dependent motion models extend the useful range of bit-rate scalability over many orders of magnitude.