An improved adaptive quantization method based on perceptual CU early splitting for HEVC

Abstract

High Efficiency Video Coding is the latest video coding standard, and it can achieve significant compression performance with numerous coding tools. It supports different quantization parameters for each different coding unit in any depth coding unit. However, the adaptive quantization (AQ) method in current HEVC suffers from the underestimated spatial activity and Lagrange multiplier selection problems. What's more, no perceptual considering are taken into the AQ model, thus it cannot obtain performance correctly and reasonably. Therefore, in this paper, we first solve the problems existed in current AQ method and then we propose a novel perceptual AQ method (PAQ) based on an adaptive perceptual CU early splitting algorithm to improve performance. Experiments demonstrate that with SSIM (Structure Similarity) as metric, it can achieve more than −9.3% BD-Rate saving with proposed method compared with the HM10.0 encoder, which outperforms than the existed methods.