A perceptual illusion I hadn't seen before

[mmcirvin]

Mr. Angry and Mrs. Calm. Which is which? How far away are you standing?

And how'd they do it? Mr. Rowland doesn't understand how it works, but I think I do: from close-up, your eye and brain's feature detectors are mostly registering high-frequency information in the picture; from far away you can't see that at all so you use the low frequencies instead. So you can make an ambiguous image like this just by superimposing images made with different Photoshop filters.

The page it came from has another one with Margaret Thatcher and Tony Blair, in which they pull a trick with the background to make it work better (to compensate for Thatcher's bigger hair).

Comments

[mmcirvin.livejournal.com]

Right. I realized after I wrote that that the use of "high-frequency" and "low-frequency" was probably what people found incomprehensible, so another way to put it is that one picture has a blurry angry face with fine details from a calm face, and the other has a blurry calm face with fine details from an angry face. When you can see the fine details, they dominate your perception of what the face looks like; stand back and they drop away.

I suspect I didn't have to stand back as far as tomscud because I am myopic, but not myopic enough that I have to wear my glasses at the computer, and I wasn't wearing them.