How to “count them,” actually.

You might already know this famous puzzle named “count them.”

At first you’ll find 12 guys. Then the upper half of their bodies moves and fits to the lower parts of the different bodies. Now you’ll find 13 guys.

I counted the bodies over and over, but didn’t succeed to discover the trick. I, however, am a professor of image processing, and finally found an answer.

Here it is.

At the first scene, we see 12 guys standing. The red parts fly to the right, and the blue parts slide to the left. This makes the second scene, which shows 13 guys standing.

The guy number zero suddenly appeared. If you follow the upper part of the guy originally numbered as one, you’ll find it replaces the upper part of the guy originally numberd as eight, whose face is dramatically changed.

The trick is this: the face of the guy number eight in the first scene is chopped and the half of it is used to fill the other guy (number eight in the first scene).

Now please watch the animation at the top of this article. Yes, this is it.