

Blue and Green color illusion - shard
http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/

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jcl
In some respects your eyes are correct: if you take the image into an editor
and apply a strong gaussian blur to it, you can clearly see the "average" of
the strips within each spiral arm are green or blue. This is why the illusion
is more effective at a distance: your eyes have surprisingly crappy color
resolution, and zooming out has the effect of blurring the colors together.

(And it's also why you completely miss the _real_ illusion -- that each solid
color in the picture is really made of tiny red, green, and blue rectangles.)

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TheSOB88
I believe the more common way to do monitors is to have tiny red, green, and
blue dots make up the rectangles. These dots, I am led to believe, are
circular.

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shizcakes
There are a number of illusions like this - a checkerboard with weird colored
tubes comes to mind - but this is easily the most dramatic of the effects.
Even when zoomed in, I still see it.

<http://en.wikipedia.org/wiki/Same_color_illusion>

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demallien
Hmmm, I followed the link in the article to the spinning woman's silhouette -
has anyone else tried that one? I don't have enough gif fu to confirm that
one, but I have the impression that the illusion is actually that you don't
see when the animation changes direction, as opposed to the animation not
changing, but your eyes telling you that it did. Can anyone confirm that?

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philwelch
When you disassemble the gif it doesn't change direction at all. It's
genuinely an ambiguous image.

Different people viewing the same animation have different "starting"
directions of rotation, too.

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trickjarrett
I read an article years ago about people who had a mutation which allowed them
higher color picking accuracy. As I recall it had to do with their rods and
cones. But I'm not positive.

I wonder if they are able to see that these are the same colors, or if it
affects them also.

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jcl
You're thinking of tetrachromats: <http://en.wikipedia.org/wiki/Tetrachromacy>

I'd expect the illusion would work just as well for them as for anyone else,
as it relies on the contrast between neighboring colors.

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trickjarrett
Ah yes I am. Thanks a lot! I couldn't find the article I mentioned, so this is
a much appreciated cite.

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pieceofpeace
Just unbelievable. Same color is perceived (very) differently by the brain
depending on its surrounding colors.

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edw519
"Colors are not what they appear, shapes are not what they appear...objects
are not what they appear."

 _Nothing_ is what it appears.

This is a great metaphor for human behavior in general.

Ask 3 people, get 4 answers.

