Illusion of lightness #3

since January 31, 2006


"Ohoshisama"*

*Ohoshisama = stars

Stars appear to scintillate.

Copyright Akiyoshi Kitaoka 2007 (November 6)

Schrauf, M., Lingelbach, B., Lingelbach, E., Wist, E.R. (1995) The Hermann grid and the scintillation effect. Perception, 24, suppl. 88-89
--- Actually the third author Elke Lingelbach discovered the effect.
Schrauf, M., Lingelbach, B., Wist, E.R. (1997) The scintillating grid illusion. Vision Research, 37, 1033-1038.
Institut fur Augenoptik Aalen --- Click "Taushungen" (illusions).

"Four cans"

The leftmost can appears to be lighter than the rightmost can, though the four cans give the same luminance.

Copyright Akiyoshi Kitaoka 2007 (October 20)


"Pig"

The left half circle appears to be lighter than the right while they are the same in luminance.

Copyright Akiyoshi Kitaoka 2007 (August 30)


"White and black disks"

Although the inner pattern of the left circle is physically the same as that of the right one, the left circle appears to be white whereas the right one appears to be black.

Copyright Akiyoshi Kitaoka 2007 (August 27)


"Full moon and the evening sun"

Although the inner pattern of the left circle is physically the same as that of the right one, the left circle appears to be lighter than the right one.

Copyright Akiyoshi Kitaoka 2007 (August 20)

This technique was proposed by Anderson and Winawer in 2005.

Anderson, B. L. and Winawer, J. (2005) Image segmentation and lightness perception. Nature, 434, 79-83.


"Brightness contrast: Miscellaneous 2007"

(a)-(k) The central square in the left half appears to be darker than that in the right one, though they are identical in luminance. (a)-(h) are the new demonstrations. (i) is the standard type. (j) is known (I guess). (k) is the enhanced brightness contrast I presented before. (l) is White's effect, where the central square in the left half appears to be brighter or lighter than that in the right one.

Copyright Akiyoshi Kitaoka 2007 (February 5)

For Jeff


"Luminous stone"

Diamond-shape parts appear to be luminous.

Copyright Aiyoshi Kitaoka 2007 (January 6)

cf. Logvinenko, A. D. (1999) Lightness induction revisited. Perception, 28, 803-816.


"Season of donguri"*

*donguri = acorns

Something appears to shed light.

Copyright Aiyoshi Kitaoka 2006 (May 12)


"Mercury"

The inner square appears to be grayish though it is white. This is the monochromatic watercolor effect.

Copyright Aiyoshi Kitaoka 2006 (March 31)

cf. watercolor effect:

Pinna B, Brelstaff G, Spillmann L, 2001 "Surface color from boundaries: a new `watercolor' illusion'' Vision Research 41 2669-2676
Pinna B,Werner J S, Spillmann L, 2003 "The watercolor effect: a new principle of grouping and figure-ground organization'' Vision Research 43 43-52


"Yellow light pyramid"

Yellow dots can be seen at the crossing of the grating though this image consists only of blue, black and white.

Copyright Aiyoshi Kitaoka 2006 (January 31)


Lightness illusion 2

Lightness illusion


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