US Patent 9129445 Efficient tone-mapping of high-bit-depth video to low-bit-depth display

Several embodiments of an efficient tone mapping of high bit depth video to low bit depth displays are disclosed. In one embodiment, a system maps an input image data of a high dynamic range (HDR) onto output image data of a lower dynamic range (LDR) and where the mapping does not transform the input image data from one color space to another color space. One embodiment comprises a tone mapping module which outputs a tone-mapped luminance signal for output image data and a color mapping module which outputs chroma signals for the output image data. Intermediate image processing steps may be avoided and hence may increase the efficiency of the mapping.