ABSTRACT
Tone reproduction operators normally compress luminance values, rather than work directly on the red, green, and blue components of a color image. The main classification scheme hinges upon the realization that tone reproduction operators are based on insights gained from various disciplines. The key issue in tone reproduction is then to compress an image while at the same time preserving one or more attributes of the image. Different tone reproduction algorithms focus on different attributes such as contrast, visible detail, brightness, or appearance. Ideally, displaying a tonemapped image on a low dynamic range display device would create the same visual response in the observer as the original scene. Edge-preserving smoothing operators may also be used to compute a local adaptation level for each pixel, which may be used in a spatially varying or local tone reproduction operator. Both global and local operators are often inspired by the human visual system.
