Efficient Inter-Layer Motion Compensation for Spatially Scalable Video Coding

In this paper, an efficient inter-layer motion-compensation technique is proposed for enhancement layer in spatially scalable video coding. The proposed approach exploits the prediction residue correlation between consecutive spatial layers. In enhancement-layer motion compensation, it selects the method with the lowest rate-distortion (RD) cost from three schemes: pyramid motion compensation, subband motion compensation, and encoding the enhancement layer with no base-layer information. To reduce the block artifacts of the enhancement-layer prediction used in the subband method, extended edge prediction is introduced in the proposed approach. Compared with the current scalable H.264/AVC extension (SVC) motion-compensation scheme, our experimental results show that the proposed method exploits the redundancy between the base layer and the enhancement layer more efficiently and hence improves the coding performance. It achieves an improvement up to about 1dB in the enhancement-layer encoding for different coding parameters and video sequences.

I. Introduction

With the requirement that a single video bitstream should flexibly provide several different spatial resolutions to satisfy various channel conditions and customers with different bitrate, computational, and power capabilities, spatial scalability has become an attractive feature in many video applications. The video bitstream is desired to be partitioned in such a way that the base layer is decoded independently to form a lower resolution sequence, and the enhancement layers, which contain additional refinement data, can be decoded to provide higher resolutions.