Surround articulation. II. Lightness judgments.
It has been hypothesized that to achieve color constancy, lightness judgments require an estimate of the illuminant. A companion paper [J. Opt. Soc. Am. A 16, 793 (1999)] suggests that surround articulation enhances the likelihood that a global luminance edge will be interpreted as being due to changes in illumination rather than in reflectance. Articulation is the process of adding equally spaced incremental and decremental patches within a surround while preserving the surround's space-average luminance. Such a process results in lightness judgments that correlate perfectly with equal local ratio matches. For decrements, lightness constancy does not require articulation. These findings help explain why Arend and Goldstein [J. Opt. Soc. Am. A 4, 2281 (1987)] obtained color constancy with complex Mondrian surrounds but not with simple center surrounds.
Schirillo
J A
JA
Department of Psychology, Wake Forest University, Winston-Salem, North Carolina 27109, USA.
D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D007600:Judgment; D008027:Light; D008297:Male; D010775:Photic Stimulation / Q000379:methods