Generalization of Color-Difference Formulae for any Illuminant and any Observer by Perfect Color Constancy Actuation in a Color-Vision Model Based on the OSA-UCS System

Abstract: Most current color-difference formulae are based on color-difference data for the CIE 1964 observer adapted to D65 illuminant. The generalization of these formulae to any illuminant adaptation and to any observer needs a psychometric color-vision model for converting the psycho-physical color from any visual situation to that of the CIE 1964 observer adapted to D65. This work considers the psychometric color-vision model based on the Optical Society of America - Uniform Color scales (OSA-UCS) system [J. Opt. Soc. Am. A 21, 677 (2004); Color Res. Appl. 30, 31 (2005)]. Following this model, the color conversion is obtained in the hypothesis that perfect color constancy exists in the color-difference evaluation