scholarly journals Local and global processes in surface lightness perception

1995 ◽  
Vol 57 (2) ◽  
pp. 125-135 ◽  
Author(s):  
Joseph Cataliotti ◽  
Alan Gilchrist
Keyword(s):  
Lightness Perception ◽  
Surface Lightness

Anchoring of Surface Lightness by Area and Luminance

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 153-153
Author(s):  
A L Gilchrist
Keyword(s):  
Relative Area ◽  
Stimulus Contrast ◽  
Lightness Perception ◽  
Empirical Results ◽  
Average Luminance ◽  
The Many ◽  
Surface Lightness ◽  
Luminance Range

Relative luminance is fundamental to lightness perception, but can be used to predict specific lightness values only when coupled with an anchoring rule. Empirical results indicate that, in simple displays, lightness is anchored by the highest luminance (white) rather than by the average luminance (middle gray). This implies that increasing the luminance range of a stimulus causes grayness induction: the lower luminance values become darker gray while the highest luminance remains unchanged, as many so-called brightness induction experiments have shown. Yet sometimes increasing the luminance range of a stimulus causes luminosity induction: the highest luminance becomes increasingly self-luminous while the lowest luminances remain unchanged. Whether grayness induction or luminosity induction results from an increase in stimulus contrast depends on relative area. A few simple, yet hitherto unrecognised, rules that describe how anchoring by highest luminance combines with anchoring by largest area appear to be consistent with the many published reports on area and lightness/brightness. These findings add to the accumulating evidence that many phenomena previously attributed to contrast are much better understood in terms of anchoring.

Lightness Perception Can Be Affected by Surface Curvature from Stereopsis

Perception ◽  
1994 ◽  
Vol 23 (8) ◽  
pp. 869-881 ◽  
Author(s):  
David Buckley ◽  
John P Frisby ◽  
Jonathan Freeman
Keyword(s):  
Present Report ◽  
Three Dimensional ◽  
Surface Shape ◽  
Sharp Change ◽  
Planar Surface ◽  
Lightness Perception ◽  
Starting Point ◽  
Integrated Interpretation ◽  
Shape Data ◽  
Surface Lightness

It is demonstrated that lightness perception can be affected by shape from stereopsis. The starting point was a report by Knill and Kersten that the perceived lightness of a monocularly viewed surface can be affected by outline-contour cues indicating that the surface is three-dimensional (3-D). In that study stimuli consisted of two equally sized abutting regions each having the same vertical linear-intensity ramp, so that the horizontal abutting boundary of the two patches created a sharp change in intensity. When this version of the Craik-O'Brien - Cornsweet stimulus has a rectangular outline, it exhibits the standard simultaneous contrast illusion: equivalent patches in the top and bottom regions appear to have different brightness despite having the same luminance. Knill and Kersten replicated this phenomenon with stimuli whose outline-contour cues were consistent with a flat (planar) surface. They found, however, that the illusion was greatly reduced in stimuli with outlines consistent with two abutting 3-D quarter cylinders, for which equivalent regions in the two halves appeared of similar lightness. Knill and Kersten interpreted this effect in terms of surface-lightness computations that took into account 3-D surface shape to achieve an integrated interpretation of the luminance and shape data. In the present report three experiments are described for which these earlier findings were taken as the starting point. In the first experiment the results were replicated by the use of a different methodology. In the second experiment it was shown that shape-from-stereo can produce similar effects on lightness perception to that caused by shape-from-contour. Real 3-D objects with curved surfaces, luminance profiles of the Knill and Kersten type, and carefully controlled outline-contour cues were used so that the objects appeared flat when viewed monocularly but curved in 3-D when seen binocularly. The third experiment was a control confirming that the stereo effect was not simply due to differences caused by monocular versus binocular viewing. It is concluded that the human visual system uses stereo cues, as well as outline-contour cues, in the interpretation of luminance data to recover surface lightness.

scholarly journals The effects of global grouping laws on surface lightness perception

2004 ◽  
Vol 66 (5) ◽  
pp. 792-799 ◽  
Author(s):  
Songjoo Oh ◽  
Jung-Oh Kim
Keyword(s):  
Lightness Perception ◽  
Surface Lightness

Lightness perception for different size displays under various surround conditions

2016 ◽  
Vol 2016 (20) ◽  
pp. 1-5
Author(s):  
YungKyung Park ◽  
Hyosun Kim ◽  
Young-jun Seo ◽  
YoonJung Kim
Keyword(s):  
Lightness Perception

scholarly journals Lightness perception for surfaces moving through different illumination levels

2016 ◽  
Vol 16 (15) ◽  
pp. 21 ◽  
Author(s):  
Matteo Toscani ◽  
Suncica Zdravkovic ◽  
Karl R. Gegenfurtner
Keyword(s):  
Lightness Perception

scholarly journals What image features guide lightness perception?

2018 ◽  
Vol 18 (13) ◽  
pp. 1 ◽  
Author(s):  
Minjung Kim ◽  
Jason M. Gold ◽  
Richard F. Murray
Keyword(s):  
Image Features ◽  
Lightness Perception

scholarly journals Testing the role of Michelson contrast for the perception of surface lightness

2016 ◽  
Vol 16 (11) ◽  
pp. 17 ◽  
Author(s):  
Christiane B. Wiebel ◽  
Manish Singh ◽  
Marianne Maertens
Keyword(s):  
Surface Lightness

scholarly journals The Place of White in a World of Grays: A Double Anchoring Theory of Lightness Perception

2017 ◽  
Author(s):  
Paola Bressan
Keyword(s):  
Weighted Average ◽  
Visual Scene ◽  
Lightness Perception ◽  
New Model ◽  
Mathematical Simulations ◽  
Gestalt Grouping ◽  
Gestalt Grouping Principles

The specific gray shades in a visual scene can be derived from relative luminance values only when an anchoring rule is followed. The double-anchoring theory I propose in this article, as a development of the anchoring theory of Gilchrist et al. (1999), assumes that any given region (a) belongs to one or more frameworks, created by Gestalt grouping principles, and (b) is independently anchored, within each framework, to both the highest luminance and the surround luminance. The region's final lightness is a weighted average of the values computed, relative to both anchors, in all frameworks. The new model accounts not only for all lightness illusions that are qualitatively explained by the anchoring theory but also for a number of additional effects, and it does so quantitatively, with the support of mathematical simulations.

scholarly journals Measuring perceptual scales of perceived surface lightness: a comparison between MLDS and matching

2016 ◽  
Vol 16 (12) ◽  
pp. 817
Author(s):  
Christiane Wiebel ◽  
Guillermo Aguilar ◽  
Marianne Maertens
Keyword(s):  
Surface Lightness
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