Patent ID: 7656567

Claim:
A method for selecting a best three color solution for a Commission Internationale de l'Éclairage L*a*b* (CIE_Lab) request comprising: generating a three color database of CIE_Lab values at specified colorant input levels in a color proofer system; finding a closest point in said database with colorant input levels which will produce a CIE_Lab value that is closest to the CIE_Lab request; selecting a matrix of points centered on the closest point; fitting a linear model to the matrix of points; creating an output color consisting of a set of colorant levels using the linear model; forming a surface subset of the database comprising all points that have a minimum or a maximum colorant input level for one or more of the input colorants; computing a difference of measured CIE_Lab values for each point in the surface subset to the CIE_Lab request; selecting a closest surface point as a surface point with the minimum CIE_Lab difference; computing a CIE_Lab center of the database; computing a first distance between the CIE_Lab request and the CIE_Lab center; computing a second distance between the CIE_Lab for the closest surface point and the CIE_Lab center; and computing a gamut indicator as the second distance minus the first distance; calculating a variance of an estimated output color using at least the gamut indicator.