Abstract

The present study examined whether two rules of lightness perception proposed by Li and Gilchrist (1999), the 'highest luminance as white rule' and the 'area rule,' can be extended to chromatic domain under two lighting conditions. The Disk-Ganzfeld display was employed for this purpose. The study further sought to compare lightness perception of achromatic stimuli with that of chromatic stimuli by presenting achromatic and chromatic stimuli in the center of the Ganzfeld. The results demonstrated that the two rules by Li and Gilchrist are applicable to lightness perception consisting of the achromatic Ganzfeld with chromatic center stimuli and that the visual system utilizes these rules even under two different lighting conditions. Finally, a comparison of the assessed lightness values of achromatic and chromatic Disk stimuli with the same Munsell values revealed that the achromatic Disk stimuli are perceived lighter than those of red, yellow, green, and blue with Munsell values of 5 or 7, but the lightness perception properties of purple colors are very similar to that of achromatic colors.