Adaptive residual mapping for an efficient extension layer coding in two-layer HDR video coding

In the absence of a commercial High Dynamic Range (HDR) distribution pipeline, two-layer backward-compatible HDR video coding is a viable solution for the imminent transition from Low Dynamic Range (LDR) to HDR content transmission. However, the performance of a two-layer coding solution is governed by the extension layer coding performance. In this paper, we propose an improved two-layer backward-compatible HDR video coding solution based on an adaptive residual mapping for the extension layer, keeping in view the performance of High Efficiency Video Coding (HEVC) being used to code this information. The proposed solution outperforms the reference method achieving averaged PU-PSNR improvements of up to 5.05 dB. The proposed method also shows potential of achieving the same HDR quality as the single layer coding solution with a minimum bitrate overhead and acceptable LDR quality in the base layer.