Optimal shutter speed sequences for real-time HDR video

Abstract

A technique to create High Dynamic Range (HDR) video frames is to capture Low Dynamic Range (LDR) images at varying shutter speeds. They are then merged into a single image covering the entire brightness range of the scene. While shutter speeds are often chosen to vary by a constant factor, we propose an adaptive approach. The scene's histogram together with functions judging the contribution of an LDR exposure to the HDR result are used to compute a sequence of shutter speeds. This sequence allows for the estimation of the scene's radiance map with a high degree of accuracy. We show that, in comparison to the traditional approach, our algorithm achieves a higher quality of the HDR image for the same number of captured LDR exposures. Our algorithm is suited for creating HDR videos of scenes with varying brightness conditions in real-time, which applications like video surveillance benefit from.