Crater illusion

An apparent convex changes to an apparent concave, vice versa, when the image is rotated through 180 degrees.

since January 18, 2013


A standard image, which shows an apparent concave in the center of the left image and an apparent convex in the center of the right image.


Figure-ground reversible images


Looks like a caldera.


Blue craters


"A red blood cell and a red hat"

The center of the left disk appears to be concave while the center of the right one appears to be convex.

Copyright Akiyoshi Kitaoka 2013 (January 18)


Colored standard images


Figure-ground reversible images


"Double moats and double embankments"


Figure-ground reversible images


Square crater illusion


"Canal and bridges"


Multi-square crater illusion


Figure-ground reversible images


Rings of the crater illusion


Ramachandran's crater illusion


Bevel, a crater illusion


Crater illusion and the optimized Fraser-Wilcox illusion Type IIa


"Legs of an octopus"

Crater illusion

Copyright Akiyoshi Kitaoka 2013 (January 18)


"Rotation of crater rings"

The left ring appears to rotate counterclockwise while the right clockwise.

Copyright Akiyoshi Kitaoka 2013 (January 18)


cf.

"Coil springs"

Bright regions appear to be in front and dark ones behind. This is not the crater illusion.

Copyright Akiyoshi Kitaoka 2013 (January 18)

Copyright Akiyoshi Kitaoka 2013 (January 18)


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