
Akiyoshi Kitaoka is a Professor of Psychology at the College of Letters, Ritsumeikan University, in Kyoto, Japan.
As we've established before, he's behind a majority of the most devious optical illusions on the internet.
He's come up with another one, which he recently tweeted:
2色法によるイチゴの錯視。この画像はすべてシアン色(青緑色)の画素でできているが、イチゴは赤く見える。 Strawberries appear to be reddish, though the pixels are not. https://t.co/Ginyhf61F7— Akiyoshi Kitaoka (@Akiyoshi Kitaoka) 1488244057
There are no red pixels in the image.
We checked it out, he's right, obviously.
Picture: @AkiyoshiKitaoka/Twitter/Screengrab
It's definitely a neutral grey.
So how is the illusion done?
Colour constancy - your brain is attempting to colour correct the world in different light - it expects to see red strawberries, so tries to.
Bevil Conway, an expert from the National Eye Institute, told Vice:
If you imagine walking around outside under a blue sky, that blueness is, in some sense, colour-contaminating everything you see.
In this picture, someone has very cleverly manipulated the image so that the objects you're looking at are reflecting what would otherwise be achromatic or grayscale, but the light source that your brain interprets to be on the scene has got this blueish component.
You brain says, 'The light source that I'm viewing these strawberries under has some blue component to it, so I'm going to subtract that automatically from every pixel.' And when you take grey pixels and subtract out this blue bias, you end up with red.
If you like optical illusions he's worth a follow.
You'll get more brain-melting images such as these:
「頭から光が出ているように見える顔出し」 The center of the image appears to be bright. https://t.co/0IWwB14Tbw— Akiyoshi Kitaoka (@Akiyoshi Kitaoka) 1488364924
"Bavarian" (2008): The image appears to bulge out with illusory motion, though this checkerboard pattern consists o… https://t.co/e9PDV9VbRf— Akiyoshi Kitaoka (@Akiyoshi Kitaoka) 1488359478
"Ascending dragon": The spiral appears to contract. https://t.co/9Bs1yCqSM2— Akiyoshi Kitaoka (@Akiyoshi Kitaoka) 1488362092
We need a lie down.