Motion-Compensated Scan Based Wavelet Transform for Video Coding

ABSTRACT 2D DWT can be extended to 3D an thus applied to video coding [1, 2, 3, 4, 5]. Such video codecs take advantage of both coding efficiency and scalability of the wavelet transform. Some promising new video coding methods are based on 3D subband coding with motion compensation [6, 7, 8, 9, 10]. These methods provide encouraging results comparatively to MPEG. However 3D subband coding of video suffers from two drawbacks. The first one is the memory complexity required for coding 3D blocks. The second one is the lack of temporal quality resulting in temporal blocking artifacts since DWT is performed on temporal groups of frames. In this paper we propose a new motion compensated scan based temporal wavelet transform method for video coding combining the advantages of wavelet coding (performance, scalability), with acceptable reduced memory requirements and no additional CPU complexity. We also propose an efficient quality allocation procedure to ensure a constant quality over time.