Perceptual CTU Level Bit Allocation for AVS2

Abstract

With developed CTU (Coding Tree Unit) bit allocation algorithms, the video compression’s performance improved significantly. However, without the consideration of the human visual system (HVS) characteristics for most algorithms, they fail to obtain subjectively optimal results. In order to improve the image’s subjective quality of video coding, in this study, we propose a perception-aware CTU level bit allocation algorithm. A perceptual distortion metric with spatial and temporal masking effects is presented firstly, and the rate-perceptual distortion constraint function is then established to obtain the optimal quantization step for each CTU. Experiments show that the proposed algorithm achieves better subjective quality with negligible affection on rate control on RD17.0 of AVS2. In addition, we demonstrate the well compatibility of the algorithm with video coding, which means it can also be extended to other standards including H.265 etc.