Recently we developed a model that reproduces the Kanizsa square illusion based on two principles: (1) a spatial 2-D integration of luminance ratio and differentiated depth signals creates a "primary" lightness map and a depth map, respectively, which is then followed by (2) a modification of the primary lightness values under influence of the perceived depth (Kogo, Strecha, Van Gool, & Wageman...

Lightness contrast and lightness assimilation are opposite phenomena: in contrast, grey targets appear darker when bordering bright surfaces (inducers) rather than dark ones; in assimilation, the opposite occurs. The question is: which visual process favours the occurrence of one phenomenon over the other? Researchers provided three answers to this question. The first asserts that both phenomen...

White's illusion is the perceptual effect that two equiluminant gray patches superimposed on a black-and-white square-wave grating appear different in lightness: A test patch placed on a dark stripe of the grating looks lighter than one placed on a light stripe. Although the effect does not depend on the aspect ratio of the test patches, and thus on the amount of border that is shared with eith...

Lightness perception is strongly dependent on context, including the relative luminance of the adjacent surfaces, spatial configuration, and luminance contrast. The latter, local luminance contrast, is thought to be processed in relatively early stages of visual processing and has been shown to play a crucial role in lightness perception. However, more global processing, such as perceptual grou...

How the visual system detects surface reflectance - lightness - has puzzled researchers for centuries. A new study of contexts that capture the characteristic luminance range of natural scenes rules out a long-standing theory of lightness perception.

This paper proposes a gamut mapping algorithm based on color space division for color reproduction of cross media. As each color device has a limited range of producible colors, the reproduced colors on a destination device are different from those of the original device. In order to reduce the color difference between those devices, the proposed method divides the whole gamut into parabolic sh...

Recent theories of lightness perception assume that lightness (perceived reflectance) is computed by a process that contrasts the target's luminance with that of one or more regions in its spatial surround. A challenge for any such theory is the phenomenon of lightness assimilation, which occurs when increasing the luminance of a surround region increases the target lightness: the opposite of c...

A series of experiments were conducted to assess how the reflectance properties and the complexity of surface "mesostructure" (small-scale 3-D relief) influence perceived lightness. Experiment 1 evaluated the role of surface relief and gloss on perceived lightness. For surfaces with visible mesostructure, lightness constancy was better for targets embedded in glossy than matte surfaces. The res...