<title>Image distortions in stereoscopic video systems</title>

This paper discusses the origins, characteristics and effects of image distortions in stereoscopic video systems. The geometry of stereoscopic camera and display systems is presented first. This is followed by the analysis and diagrammatic presentation of various image distortions such as depth plane curvature, depth non-linearity, depth and size magnification, shearing distortion and keystone distortion. The variation of system parameters is also analyzed with the help of plots of image geometry to show their effects on image distortions. The converged (toed-in) and parallel camera configurations are compared and the amount of vertical parallax induced by lens distortion and keystone distortion are discussed. The range of acceptable vertical parallax and the convergence/accommodation limitations on depth range are also discussed. It is shown that a number of these distortions can be eliminated by the appropriate choice of camera and display systems parameters. There are some image distortions, however, which cannot be avoided due to the nature of human vision and limitations of current stereoscopic video display techniques.