Improved HEVC $$\lambda $$ λ -domain rate control algorithm for HDR video

Abstract

Widespread high dynamic range (HDR) video distribution via transmission and broadcast is imminent in the near future. However, the rate control (RC) algorithms in video coding standards, like high-efficiency video coding (HEVC), are optimized and designed for low dynamic range (LDR) content—making them inefficient in the rate-distortion (RD) sense, when applied to HDR video compression and distribution. In this paper, we propose a non-normative change to the HM16.2 HEVC \(\lambda \) -domain RC algorithm to achieve high-fidelity HDR video distribution. A new \(\lambda \) -QP relation is modeled for HDR content after assessing the suitable RD model. The results indicate that the proposed RC algorithm outperforms the default RC algorithm in HEVC, achieving on average performance gains of 1.40 dB, 0.685 units, and 0.0155 units in terms of PU-PSNR, HDR-VDP-2.2 Q factor, and HDR-VQM, respectively. Further, proposed method has bit estimation accuracy similar to the default HEVC RC algorithm. Also, the subjective evaluations corroborate the significance of the performance gained in the objective metrics.

http://bit.ly/2QljkWJ