Patent ID: 8355573

Claim:
A method for matching colors comprising: providing a first source of a first color and a second source of a second color; measuring a first set of spectral values for first color stimuli associated with the first color with a spectral measurement device controlled by a digital processing system; calculating a first set of tristimulus values from the first set of spectral values; defining a first set of human observer color matching functions, the first set of human observer color matching functions being functions of the first set of tristimulus values of the first color; calculating a first set of corrected tristimulus values from the first set of spectral values using the first set of human observer color matching functions; measuring a second set of spectral values for second color stimuli associated with the second color with the spectral measurement device controlled by the digital processing system; calculating a second set of tristimulus values from the second set of spectral values; defining a second set of human observer color matching functions, the second set of human observer color matching functions being functions of the second set of tristimulus values of the second color; calculating a second set of corrected tristimulus values from the second set of spectral values using the second set of human observer color matching functions; determining a difference between the first set of corrected tristimulus values and the second set of corrected tristimulus values; adjusting one of the first and the second source to reduce the difference; and wherein the first and second set of human observer color matching functions are defined according to the equation xyz C (λ)=α( {right arrow over (XYZ)} S ) xyz S (λ)+(1.0−α( {right arrow over (XYZ)} S )) xyz M (λ) wherein xyz M (λ) denotes human observer functions defined by visually matching white colors, xyz s (λ) denotes human observer functions defined by visually matching saturated colors, xyz c (λ) refers to the corrected human observer function, and α({right arrow over (XYZ)} s ) is a function of saturated tristimulus values {right arrow over (XYZ)} s calculated from xyz s (λ).