Parabolic achromatic color matching functions : Dependence on incremental and decremental luminance

Either the brightness or lightness of a disk surrounded by an annulus is characterized in the most general case by a parabolic function of the annulus luminance when plotted on a log-log scale. This relationship has been mod-eled with a theory of achromatic color computation based on edge integration and contrast gain control [J. Vis. 10, 1 (2010)]. We tested predictions of this model in new psychophysical experiments. Our results support the theory and reveal a previously unobserved property of parabolic matching functions that depends on the disk contrast polarity. We interpret this property in terms of a neural edge integration model incorporating data from macaque monkey physiology that indicates different physiological gain factors for incremental and decremental stimuli.(c) 2023 Optica Publishing Group