Improved Scheme for Sample Adaptive Offset in HEVC
Zhao Chua · Video Engineering · 2015
Sample adaptive offset(SAO)is adopted in the state-of-the-art video coding standard HEVC,including band offset(BO)and edge offset(EO) to attenuate ringing artifacts,which are more likely to appear after transform and quantization.Although BO spreads over 4 continuous bands,it is a fixed strategy for different blocks with the same size and does not consider a range narrower or wider than four bands.In this paper,band distribution of coding tree block(CTB) is analyzed by utilizing histogram,and adaptively bring a block's texture characteristics in intra prediction.Based on the analysis,an improved strategy is further developed for BO in SAO for HEVC.Experimental results indicate that significant performance and up to 7.53%,BD-rate reduction is achieved in chrome with marginal running time increase and the subjective visual quality is enhanced in the edge under common test conditions of HEVC reference software version 10.0.