Neat visual illusion
Take a look at this image.
My first explanation is pretty obvious.. it's caused by the gradual changes in the colours and contrast in surrounding squares.
A friend suggested the checkerboard pattern is also at fault here..
To quote:
Our minds want to see the perfect idea of a checkerboard (alternate DIFFERENT colors) hinted at by the picture, so we are "not seeing" the filters applied to the picture like shadows or graduation of contrast that make the intensity the same as it hits our eyeball. The sense of a border is much stronger than the sense of absolute color values.
That explanation also makes perfect sense, in reality probably a combination of both.
Neat.
Comments
I dunno. I covered all the areas except the two squares, and they still loked very different.
Posted by: Dan Isaacs | October 1, 2002 12:10 AM
Pull out a graphics editor and have at it :)
I did.. they really are the same colour..
Posted by: kasia | October 1, 2002 12:11 AM
Take a piece of paper. Make two small holes in it so if fits over the two squares. Place it on your screen, so that you only see the background color of the two squares (not the letters)... Voila! Thats how I did it :)
Posted by: Dennis S.H. Andersen | October 1, 2002 03:13 AM
I'll accept that. I just used my fingers. And Evolution has not yet panned out where covering optical illusions with ones fingers is concerned.
Or, God did not wish for me to cover optical illusions with my fingers.
Or, Evolution [b]has[/b] panned out, and I've just been left behind.
Posted by: Dan Isaacs | October 1, 2002 07:41 AM
Hmm. Whatta ya know. UBB code doesn't work. Must not post and eat cereal at same time.
Posted by: Dan Isaacs | October 1, 2002 07:42 AM
Wow, this is for real. I cut out parts of both and moved them aside: they're the same color. Wow.
second image here
Posted by: Steve | October 1, 2002 02:23 PM
I would guess that it's not the checkerboard that's at fault it's the suggestion of shadow. If I recall correctly, the way our brain perceives images tends to compensate for lighting conditions in order to more accurately determine the underlying color of the object (presumably a trait that helps one not be selected out due to varied lighting conditions while mushroom hunting). I perceive the shadowed dark square adjacent to A to be the same color as A and a uniform color across the surface even though I can see a color gradiant due to the "shadow" falling across it.
It would be interesting to experiment by modifying the shadow and shapes. If rather than squares you had smooth gradients (point sample the centers and blend) and the same perception of difference in color was achieved, then it would be more attributable to perception of shadow than any to a sense of contrasting border.
(yeah, I'll get around to trying that in about 6 months when I finish cleaning up this giant poo pile our idiot^H^H^H^H^H lead programmer has left behind)
Posted by: PopeMatt | October 1, 2002 02:44 PM
I agree, its a good illusion! I have a question way off the topic though. Kasia, I saw your picture at www.unix-girl.com/images/kasia.jpg
& was wondering how long ago that picture was taken? Don't worry I am not a stalker. I checked & rechecked my posting, I know you hate acronyms so I didn't usa any.
Posted by: Ron | October 1, 2002 03:29 PM
Hmmm. Definitely has potential in the general digital color theory classes I give.
I'm surprised I never came across this before.
Thanks!
Posted by: Naladahc | October 1, 2002 05:09 PM
This delightful illusion is from Dr. Edward Adelson, Professor of Vision Science at MIT. His description of this illusion is here.
Posted by: Steve | October 1, 2002 07:54 PM
Cool! Thanks Steve.
Posted by: kasia | October 1, 2002 08:00 PM
ur site is very good.i want to know static illusion visual illusion dominance subordinate etc.
Posted by: manisha | November 14, 2002 11:14 AM
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Posted by: faget | June 18, 2003 09:41 AM