David M. Baylon

Compression Efficiency Improvement over HEVC Main 10 Profile for HDR and WCG Content

The paper presents the joint proposal by Arris, Dolby and InterDigital as a response to the Call-for-Evidence of the High Dynamic Range and Wide Color Gamut (HDR/WCG) video compression in MPEG. The joint proposal introduces a set of new HDR coding technologies, including the IPT-PQ color space, the adaptive reshaping process, the color enhancement filters, and the adaptive transfer function. These new coding technologies are applied to the decoded output of an HEVC decoder. Hence, no changes to the lower level logics of the HEVC decoder are required to implement the proposal. Formal subjective tests conducted by MPEG confirmed that the proposal could achieve significant subjective quality improvements over the HEVC Main10 anchors at similar bit rates for HDR/WCG video content.

On metrics for objective and subjective evaluation of high dynamic range video

In high dynamic range (HDR) video, it is possible to represent a wider range of intensities and contrasts compared to the current standard dynamic range (SDR) video. HDR video can simultaneously preserve details in very bright and very dark areas of a scene whereas these details become lost or washed out in SDR video. Because the perceived quality due to this increased fidelity may not fit the same model of perceived quality in the SDR video, it is not clear whether the objective metrics that have been widely used and studied for SDR visual experience are reasonably accurate for HDR cases, in terms of correlation with subjective measurement for HDR video quality. This paper investigates several objective metrics and their correlation to subjective quality for a variety of HDR video content. Results are given for the case of HDR content compressed at different bit rates. In addition to rating the relevance of each objective metric in terms of its correlation to the subjective measurements, comparisons are also presented to show how closely different objective metrics can predict the results obtained by subjective quality assessment in terms of coding efficiency provided by different coding processes.

On the Design of Optimal Sub-Pixel Motion Compensation Interpolation Filters for Video Compression

In this paper, the design of optimal temporal prediction for video coding is addressed as a quantization design problem. In the proposed framework, a codebook consisting of a set of interpolation filters is optimized to achieve rate-distortion optimality. The optimization process jointly affects two aspects of motion compensation to achieve rate distortion optimality: 1) The size of the codebook or motion vector (MV) resolution and 2) The filter coefficients for each sub-sample interpolation filter. Note that filter coefficients dictate the behavior of the interpolation filter in terms of signal-noise shaping.