Spatiotemporal Perception Aware Quantization Algorithm For Video Coding

Abstract

Adaptive quantization (AQ) proves to be an effective tool to improve coding performance. In this paper, we propose an adaptively spatiotemporal perception aware quantization algorithm to increase subjective coding performance. First, the perceptual complexity models are conducted with spatial and temporal characteristics to measure the spatiotemporally perceptual redundancies, respectively. With the help of the models, the adaptively spatial and temporal quantization parameter (QP) offsets are then calculated for each coding tree unit (CTU), respectively. Finally, the perceptually optimal Lagrange multiplier of each CTU is determined with the spatial-temporal QP offset. Experimental results show that the proposed algorithm reduces 8.6% BD-Rate with SSIM (Structural Similarity Index Metric) in average over the AVS2 (the second generation of Audio Video Coding Standard) reference software RD17.0 in Low-Delay P (LDP) configurations. The subjective assessment proves the proposed algorithm can significantly reduce the bit rates with the same subjective quality.