Patent ID: 7103217

Claim:
A color management method for converting internal color values to CMYK color values, wherein the method utilizes a color transform that converts CMYK color values to internal color values, the color transform being arranged as a plurality of three-dimensional CMY space to internal color space lookup tables, each associated to a different K value, the method comprising the steps of: receiving a target internal color value; selecting one of the plurality of CMY lookup tables that contains the target internal color value based on a lightness value and neutrality of the target internal color value, wherein said selecting step comprises determining the neutrality of the target internal color value; selecting the CMY lookup table associated with the largest value of K which contains the target internal color value in the case that the target internal color value is determined to be neutral; and selecting the CMY lookup table associated with the smallest value of K which contains the target internal color value in the case that the target internal color value is determined to be non-neutral; interpolating a CMY value from the selected lookup table and the target internal color value, wherein said interpolating step comprises computing an error in the interpolated CMY value; comparing the computed error to a predetermined error threshold; providing the interpolated CMY value, in the case that the predetermined threshold is met; and selecting a new CMY lookup table, in the case that the predetermined error threshold is not met, and interpolating a new CMY value from the newly selected lookup table and the target internal color value; and providing the interpolated CMY value and the associated K value from the selected table as the converted CMYK color value.