Intra prediction with adaptive CU processing order in HEVC

Abstract

The High Efficiency Video Coding (HEVC) utilizes Z-scan order to process coding units (CUs). For intra prediction, this order cannot fully exploit the spatial correlation between adjacent CUs. After transform and quantization, the residue still contains lots of energy along edges which consumes many bits for compression. To effectively reduce the residue energy along edges, a novel intra prediction approach is proposed, where the CU processing order is changed adaptively. Two additional orders are introduced in this paper besides traditional Z-scan order. Up to 1.9% bit saving is achieved in our experiments on HEVC test model. We also propose two fast order selection algorithms and the observed gains are obtained with 27% and 2% encoding time increase compared to HEVC, respectively.

Enhanced Intra Prediction Based on Adaptive Coding Order and Multiple Reference Sets in HEVC

“…The goal of the adaptive coding order method is to find the best coding order that minimizes the RD cost of a frame or a block. Several related studies have been reported on top of H.264/AVC and HEVC [19][20][21]. Although the reported methods are somewhat different, their results are very similar.…”