Gamut mapping preserving local luminance differences

A method of remapping colors in an original document, preparatory to use in la system having a different system gamut than originally applied, including:

• receiving a set of pixels defining at least a portion of an image, each pixel therein mapped to a first set of original colors.
• for each pixel in said set, remapping said pixel from said set of original colors to a new set of colors within said system gamut;
• determining a comparison metric, comparing said set of pixels mapped to said first set of original colors and said set of pixels mapped to said new set of colors, wherein said comparison metric is a difference between luminance values of said set of pixels mapped to said first set of original colors and said set of pixels mapped to said new set of colors;
• and
• applying said comparison metric to said colors after remapping to provide corrective spatial feedback to said pixel set to adjust color selection within said system gamut.

A gamut mapping system, including:

• an image:
• input, receiving pixels directed thereto mapped to a first set of colors, which may not be reproducible at a selected output device;
• and
• a first gamut mapping device, remapping said pixels mapped to said first set of colors to a second set of colors reproducible at said selected output device;
• a corrective spatial feedback system, having:
• a first input receiving said pixels mapped to said first set of colors,
• a second input receiving said pixels mapped to said second set of colors, and producing a comparison signal representing a difference therebetween, said difference being between an original pixel color luminance component and a new pixel color luminance;
• and
• a signal ladder, adding said comparison signal to a luminance value of said pixels mapped to said second set of colors, to adjust said luminance values, while maintaining other color defining values.