Minimal Capture Sets for Multi-Exposure Enhanced-Dynamic-Range Imaging

Multi-exposure enhanced-dynamic-range imaging (MEDRI) is a common technique for overcoming the limited dynamic range of digital cameras. In MEDRI, the target scene is captured multiple times at different camera exposure settings. The resulting set of low-dynamic range images is then combined using software to create a single high-dynamic-range digital image of the target scene. In this paper we describe a general analytical framework for MEDRI systems. Based on this framework, we then present an optimal greedy algorithm for finding the minimum number of exposures required to capture the entire dynamic range of any MEDRI system. The resulting set of exposures is often significantly smaller than the entire set of available camera exposure settings, and therefore represents a significant speed-up in the HDR-image-acquisition process. We demonstrate this benefit via a case study. For the system considered, we show that minimal exposure set found via the optimal algorithm reduces the number of required LDR exposures from 16 to 3