RT Journal Article
A1 Bloj, Marina
A1 Ripamonti, Caterina
A1 Mitha, Kiran
A1 Hauck, Robin
A1 Greenwald, Scott
A1 Brainard, David H.
T1 An equivalent illuminant model for the effect of surface slant on perceived lightness
JF Journal of Vision
JO JOV
YR 2004
DO 10.1167/4.9.6
JF Journal of Vision
VO 4
IS 9
SP 6
OP 6
SN 1534-7362
AB In the companion study (C. Ripamonti et al., 2004), we present data that measure the effect of surface slant on perceived lightness. Observers are neither perfectly lightness constant nor luminance matchers, and there is considerable individual variation in performance. This work develops a parametric model that accounts for how each observer’s lightness matches vary as a function of surface slant. The model is derived from consideration of an inverse optics calculation that could achieve constancy. The inverse optics calculation begins with parameters that describe the illumination geometry. If these parameters match those of the physical scene, the calculation achieves constancy. Deviations in the model’s parameters from those of the scene predict deviations from constancy. We used numerical search to fit the model to each observer’s data. The model accounts for the diverse range of results seen in the experimental data in a unified manner, and examination of its parameters allows interpretation of the data that goes beyond what is possible with the raw data alone.
RD 12/6/2019
UL https://doi.org/10.1167/4.9.6