An autostereogram is a single image that gives an illusion of depth. A 3D object pops out or, more frequently, pops in what looks like a plane of random dots or a pattern. The illusion of depth is created because the eye is tricked into focusing on an imaginary object that appears to be at a further depth than the plane at which the image is held. Specifically, this kind of 3d image is called a wallpaper auto stereogram or a random dot autostereogram. To make a customised wallpaper autostereogram, we will be using a free windows utility to make the autostereogram called StereoMaker. It can be downloaded for free from Ferow2k's Software (964 KB). The site is in Spanish, but the installer has support for the English language. An autostereogram works on two com¬ponents, a depth mask and a pattern.