Autostereoscopic Displays
Introduction
An autostereoscopic display allows the viewer to see the three-dimensional structure of a scene, including moving the head to "look around" the object, without using any sort of special viewing apparatus. Examples include holographic displays, parallax techniques, and multiplanar methods.
Parallax techniques
Parallax techniques are one interesting example. The basic idea is actually quite old, and it is based in part on generating separate views for the left and right eyes. This sounds like stereo, but the difference is presentation and the fact that no special eyewear is needed. The image on this page shows the basic idea. A series of vertical opaque blocking strips are arranged in front of the display. Depending on the distance the viewer is from the screen and the size and position of the strips, there are areas of the display visible only to the left eye, areas visible only to the right, and areas visible to both. By presenting the left (right) eye views in strips in the approrpiate areas, the viewer sees a clear stereo image. Moreover, the viewer can move their head from side to side across a relatively small, but reasonable range to "look around" objects in the scene. Alternatively, several viewers can simultaneously view the stereo image, provided they are relatively close to one another.
