The heterogeneous profile of today's networks and playback devices imposes the need for scalable video coding. Wavelet-based video coding technology can provide state-of-the-art compression performance while simultaneously supporting quality, resolution and frame-rate scalability. In this dissertation, several problems limiting the compression efficiency and functionality of wavelet-based scalable video coding schemes are tackled. The first part of our work is focused on wavelet-based video coding approaches employing in-band motion compensated prediction or in-band motion compensated temporal filtering (MCTF). These approaches produce substantial motion information overhead, which affects the compression performance, particularly when targeting low bit-rates. To resolve this problem, efficient motion information coding schemes for in-band motion estimation are proposed in this dissertation. As a second contribution, this thesis presents a novel quality-scalable motion information coding scheme for video codecs employing spatial-domain MCTF. The proposed technique outperforms state-of-the-art wavelet-based solutions. By supporting quality-scalability, the motion information bit-rate can be reduced in favor of an increased texture bit-rate, which leads to a systematically better compression performance when targeting low bit-rates. Additionally, quality-scalability of the motion information can indirectly lead to improved compression performance at higher bit-rates as well, since the complexity and corresponding accuracy of the motion field are no longer limited by the lowest bit-rate that needs to be supported. To be able to practically benefit from the proposed scheme, two rate-allocation strategies, capable of optimally distributing the available bit-budget between texture and motion information are also proposed. A final contribution of this work is a novel adaptive deblocking filter, resolving the problems caused by block-boundary discontinuities in wavelet-based video codecs employing a block-based motion model. Applying the proposed deblocking filter yields the same visual quality as using classical overlapped-block motion compensation but requires significantly less processing time when targeting a PC platform implementation.
Advanced motion information coding and deblocking techniques for scalable video compression
Barbarien, J. ((PhD) Student), Cornelis, J. (Promotor), Schelkens, P. (Jury), Munteanu, A. (Promotor), Tiberghien, J. (Jury), Pintelon, R. (Jury), Domanski, M. (Jury), Lafruit, G. (Jury), Goossens, M. (Jury). 15 dec. 2006
Scriptie/Masterproef: Doctoral Thesis