Recovering Over-/Underexposed Regions in Photographs

Abstract

When taking pictures using a commodity camera in a scene with strong or harsh lighting, such as a sunny day outdoors, we often see a loss of highlight details (overexposure) in some bright regions and a loss of shadow details (underexposure) in some dark regions. In this paper, we develop a wavelet tight frame--based approach to reconstruct a well-exposed image with better visibility of details than that with over-/underexposed regions. There are two modules in the proposed approach: one in lightness channels that inpaints the clipped lightness and adjusts image contrast, and the other in chromatic channels that inpaints the saturated color regions. The experiments show that our method can effectively repair over-/underexposed regions, and it performs better than other existing methods on tested real photographs.