Whiteness‐blackness and brightness response in a nonlinear color‐appearance model

Abstract

AbstractThe achromatic response of the nonlinear color‐appearance model is developed to predict the perceptions of whiteness‐blackness, brightness, and lightness of object colors. The distinction between whiteness‐blackness and brightness perceptions of achromatic colors is especially important in an adapting condition with nonuniform illumination or in a haploscopic match between different adapting fields. In the whiteness–blackness response, the reference gray is introduced from the viewpoint of opponency of achromatic response, and the whiteness–blackness response is divided into whiteness–grayness and grayness–blackness responses. By giving different weights for the whiteness–grayness and grayness–blackness responses, the metric lightness in the nonlinear color‐appearance model agrees very closely with the CIE 1976 L* function without any alteration to the model formulation.