DECODING AN AUTOSTEREOGRAM

If you’re one of those people who just can’t manage to train their eyes to see Magic Eye images, you’d be excused for being sceptical that there are 3D objects hidden in them at all. However, even if you don’t have the knack, here’s a way of proving that there’s something hidden in the intricate pattern after all.

First of all, create a Magic Eye image, as described in the main part of this article at Easy Stereogram Builder and download it to your PC or, if you prefer an element of surprise, just find a Magic Eye image online. Now open that image in GIMP and also open the same image as a new layer. In the Layers dialog, change the Mode to Difference and you’ll see a black image because there’s no difference between the two layers. Finally, start moving the top layer horizontally compared to the base image, a pixel at a time. After the first move the image will no longer be all back and, as you progress, parts of the hidden object will reveal themselves. Do persevere, though, and eventually the complete hidden object will appear.