Objective image quality evaluation of HDR videos captured by smartphones

Abstract

High Dynamic Range (HDR) videos attract industry and consumer markets thanks to their ability to reproduce wider color gamuts, higher luminance ranges and contrast. While the cinema and broadcast industries traditionally go through a manual mastering step on calibrated color grading hardware, consumer cameras capable of HDR video capture without user intervention are now available. The aim of this article is to review the challenges found in evaluating cameras capturing and encoding videos in an HDR format, and improve existing measurement protocols to objectively quantify the video quality produced by those systems. These protocols study adaptation to static and dynamic HDR scenes with illuminant changes as well as the general consistency and readability of the scene’s dynamic range. An experimental study has been made to compare the performances of HDR video capture to Standard Dynamic Range (SDR) video capture, where significant differences are observed, often with scene-specific content adaptation similar to the human visual system.