Improved video coding with residual prediction for extended spatial scalability

Annex G has been added to the H.264/AVC video coding standard to improve the scalability of coded video. In this annex, residual prediction is one of the main coding tools that provide efficient inter-layer prediction with moderate coding complexity. However, when residual prediction is used in an extended spatial scalability scenario, it is reported that certain visual artifacts can appear, which results in a perceived quality degradation. This paper provides a detailed analysis of the problem. Based on the analysis, a solution that involves a modified mode decision process is suggested. With the proposed method, the reported visual artifact may be completely prevented. Meanwhile, the proposed solution does not require any change to decoder and therefore does not incur any overhead to decoder complexity.