Detail-Preserving Contrast Reduction for Still Cameras

This paper describes a detail-preserving contrast reduction technique for images with excessive illumination variation. In an attempt to preserve detail, an image is first separated into its illumination and reflectance components, by a partial differential equation. The illumination component is then scaled to globally reduce contrast. This enhances the perception of detail in the dark areas but at the expense of losing detail in the bright areas. The proposed approach minimizes this loss of detail using a novel recombination strategy. Additionally, the present algorithm preserves colors, avoids halo artifacts, and can be embedded into existing still-camera pipelines.