N15457, HDR CE3: Objective metrics

This document describes the core experiment 3 (CE3) on objective metrics for evaluation of HDR video compression established at the 112th MPEG meeting. The CE relates to objective evaluation of HDR and WCG video coding technologies. The goal of the CE is to explore objective metrics appropriate for evaluating the compression performance of HDR and WCG compression.  Experience from discussion of CfE responses indicates the relatively higher importance of color errors in HDR and WCG coding than traditionally seen in video coding.  Two categories of objective metrics were identified: luminance only and color only.  As a result, this CE will develop separate luminance and color distortion metrics appropriate for HDR work. A single combined metric formed from a combination of the luminance and color metrics will be selected based on correlation with the subjective testing.  Additionally a desire was expressed to enable an objective metric visualization process in the software.