Patent ID: 8576445

Claim:
A computer implemented method for processing an input high dynamic range (HDR) image to generate an output image to be output by an output device, the method comprising: (a) mapping colors of the input HDR image from a first color space to a second color space using a tone-mapping filter, the second color space being an extended RGB color space; (b) converting the colors of the image from the second color space to a third color space, the third color space being a device independent color space; (c) scaling the colors of the image in the third color space, including: determining first and second brightness values, for which a respective first and second predetermined percentages of all colors in the HDR image have equal or lower brightness values; and shifting the colors along a brightness axis and expanding or contracting the colors uniformly in all directions in the third color space to place the first brightness value at a first normalized brightness value and to place the second brightness value at a second normalized brightness value; (d) generating a gamut mapping which maps a gamut of the image in the third color space after they have been scaled in step (c) to a gamut of the output device; and (e) converting the colors of the image, after they have been scaled in step (c), from the third color space to a fourth color space using the gamut mapping generated in step (d), to generate an output image.