A random dot autostereogram (left)encodes a 3D scene which can be "seen" with proper viewing technique.
An autostereogram is a single-image stereogram (SIS), designed to create the visual illusion of a three-dimensional (3D) scene from a two-dimensional image in the human brain. In order to perceive 3D shapes in these autostereograms, the brain must overcome the normally automatic coordination between focusing and vergence.
The simplest type of autostereogram consists of horizontally repeating patterns and is known as a wallpaper autostereogram. When viewed with proper vergence, the repeating patterns appear to float above or below the background. The Magic Eye books feature another type of autostereogram called a random dot autostereogram.
One such autostereogram is illustrated above left. In this type of autostereogram, every pixel in the image is computed from a pattern strip and a depth map. Usually, a hidden 3D scene emerges when the image is viewed with the correct vergence.
From Wikipedia, the free encyclopedia