Tone mapping is a dynamic range compression for HDR photos and HDR videos. In this mapping technique, HDR images with high contrast values are reduced in their contrast gradations so that they can be shown on normal displays
. For example, an HDR image with a dynamic range of 10 bits
or 12 bits can be converted to one with astandard dynamic range
(SDR) of 8 bits and displayed on a standard display. Since the dynamic range of HDR images, which can be 10, 12, 14 bits or more, cannot be reproduced on normal displays, with projectors or on photographic paper, the dynamic range is compressed using tone mapping to match the dynamic range of the output device.