When humans perceive the lightness of an object's surface in shadows there is an implicit assumption that cast shadows dim the surface. In two experiments, we investigated whether 5- to 8-month-old infants make this assumption about shadows. According to this shadow assumption, the apparent change in lightness produced by shadows on an object's surface are attributed to blocked light sources. I...

Whereas geometric illusions in human faces have been reported by several studies, illusions of color or lightness in faces have seldom been explored. Here, we psychophysically investigated whether lip color influences facial skin's perceived lightness. Results of Experiment 1 demonstrated that redder lips lightened and darker lips darkened the perceived complexion. These lightness or darkness i...

Interactions between the albedo and the gloss on a surface are commonplace. Darker surfaces are perceived glossier (contrast gloss) than lighter surfaces and darker backgrounds can enhance perceived lightness of surfaces. We used maximum likelihood conjoint measurements to simultaneously quantify the strength of those effects. We quantified the extent to which albedo can influence perceived glo...

Surprisingly little scientific research has been conducted on the effects of colour and lightness on the perception of spaciousness. Practitioners and architects typically suggest that a room's ceiling appears higher when it is painted lighter than the walls, while darker ceilings appear lower. Employing a virtual reality setting, we studied the effects of the lightness of different room surfac...

The effect of frying pressure on the kinetics of color changes during atmospheric and vacuum deep fat frying of Reshteh Khoshkar has been studied. The Hunter color parameters redness, yellowness, lightness and total color difference were used to estimate color changes during frying as a function of process. Lightness (L*) decreased from 85.37 to 75.01 with vacuum frying time, while redness (a*)...

A fundamental goal of research in the perception of surfaces is to understand the nature of the computations and representations underlying lightness perception. A significant challenge posed to the visual system is recovering surface lightness from the multiple physical causes that contribute to image luminance. One view asserts that the visual system decomposes the image into estimates of ill...

Synesthesia-like mappings between visual lightness and auditory pitch and between visual lightness and melodic interval were examined. When subjects rated how visual lightnesses and auditory pitches "fit together," lighter stimuli fit better with higher pitches, and darker stimuli fit better with lower pitches. These patterns were stronger against black than against white visual backgrounds; ho...

Color varies along dimensions of lightness, hue, and chroma. We used maximum likelihood conjoint measurement to investigate how lightness and chroma influence color judgments. Observers judged lightness and chroma of stimuli that varied in both dimensions in a paired-comparison task. We modeled how changes in one dimension influenced judgment of the other. An additive model best fit the data in...