Multi-exposure imaging on mobile devices

Many natural scenes have a dynamic range that is larger than the dynamic range of a camera's image sensor. A popular approach to producing an image without under- and over-exposed areas is to capture several input images with varying exposure settings, and later merge them into a single high-quality result using offline image processing software. In this paper, we describe a system for creating images of high-dynamic-range (HDR) scenes that operates entirely on a mobile camera. Our system consists of an automatic HDR metering algorithm that determines which exposures to capture, a video-rate viewfinder preview algorithm that allows the user to verify the dynamic range that will be recorded, and a light-weight image merging algorithm that computes a high-quality result directly on the camera. By using our system, a photographer can capture, view, and share images of HDR scenes directly on the camera, without using offline image processing software.