Patent Document ID: 8593693
Application ID: 12616927
Patent Status: 1

Claim One:
1. A method, operable with a processor, of performing CMYK to CMYK color conversion of input image data to preserve K color values in the input image data, the method comprising: accessing a CMYK to device independent color conversion in an input ICC profile; converting the input ICC profile to an input lookup table based on the CMYK to device independent color conversion lookup table; limiting perceptual color values in the input lookup table where K color values are present in the input lookup table; determining a set of perceptual lightness values in the input lookup table where K values in the input lookup table are greater than a threshold value; generating an output lookup table from a device independent to CMYK color conversion lookup table; converting the determined perceptual lightness values of the input lookup table to output lightness values in the output lookup table; and converting the input image data from an input CMYK color space to an output CMYK color space via the input lookup table and the output lookup table.