A nonlinear color‐appearance model using estévez‐hunt‐pointer primaries

Abstract The nonlinear color‐appearance model of Nayatani et al. is reformulated by changing the fundamentals from the Pitt to the Estévez‐Hunt‐Pointer primaries. The predictions of the reformulated model correlate with the Munsell and the NCS schemes better than those of the original. Formulas for various color‐appearance metrics are proposed, such as colorfulness, chroma, saturation, brightness (including a chromatic‐component contribution), and others. In the present model, the normalizing illuminant D 65 is used in the transformation from the CIE tristimulus values to those in the fundamental‐primary system, and the normalizing illuminance is kept at 3,000 lx. The effects of changing the normalizing illuminant to D 50 and the normalizing illuminance to 1,000 lx are studied. The results, however, show insignificant differences in the predictions of color appearance.