Patent ID: 7558436

Claim:
A system for mapping high dynamic range image data derived from a high dynamic range imaging device to render a corresponding image on a lower dynamic range display device, the high dynamic range image data including representations of relatively low intensity contrast, high spatial frequency detail and relatively low spatial frequency intensities, comprising: a filtering unit receiving the high dynamic range image data and producing high-pass filtered image data that include representations of high spatial frequency data of the high dynamic range image data, the filtering unit including: a blurring unit receiving as an input the high dynamic range image data and producing an output representing a blurred version of the high dynamic range image data; an inversion unit receiving the output from the blurring unit and producing an output representing an inverted version of the blurred high dynamic range image data; and a summing unit combining the high dynamic range image data with the output of the inversion unit while maintaining the same dynamic range as that of the high dynamic range image data to thereby produce the high-pass filtered image data; a conversion unit implemented with an intensity transform for converting the high-pass filtered image data to produce an output signal characterized by a dynamic range that is compatible with the lower dynamic range of the display device and the low intensity contrast, high spatial frequency detail of the high dynamic range image data; a reference image unit producing an output signal representing a gain and level adjustment of the high dynamic range image data; and a combining unit for combining the output signals of the conversion and the reference image units to produce a low dynamic range image with visually perceptible local area detail for display on the display device.