CONTEXT REDUCTION OF SIGNIFICANCE MAP CODING OF 4 X 4 AND 8 X 8 TRANSFORM COEFFICIENT IN HM4.0

摘要

Reducing contexts of a significance map includes merging some of the adjacent partitions of the higher frequency transform coefficients into one partition so that the significance of the coefficients in a merged partition are encoded with the same contexts. To reduce the impact of merging on coding efficiency of 4×4 blocks, the partitions of the lower frequency AC components of 4×4 blocks are not merged. To reduce the impact of merging on coding efficiency, the DC component is not merged with any AC component.