Issues with common assumptions about the camera pipeline, and their impact in HDR imaging from multiple exposures

TitleIssues with common assumptions about the camera pipeline, and their impact in HDR imaging from multiple exposures
Publication TypeJournal Article
Year of Publication2019
AuthorsRodríguez RGil, Vazquez-Corral J, Bertalmío M
Journal*Submitted*
Abstract

Multiple-exposure approaches for HDR image generation share a set of building assumptions: that color channels are independent, and that the camera response function (CRF) remains constant while changing the exposure. The first contribution of this paper is to highlight how these assumptions, that were correct for lm photography, do not hold in general for digital cameras. As a consequence, results of multi-exposure HDR methods are less accurate, and when tone-mapped they often present problems like hue shifts and color artifacts. The second contribution is to propose a method to stabilize the CRF while coupling all color channels, that can be applied to both static and dynamic scenes, and yields artifact-free results that are more accurate than those obtained with state-of-the-art methods according to several image metrics.