Data compression and depth shape reproduction of stereoscopic images

Three-dimensional visual communications, realized with stereoscopic images, can achieve total display realism. To create a three-dimensional (3-D) transmission and display system, the large amount of information typically contained in natural images must be reduced and coded by an efficient technique appropriate for stereoscopic images. As the initial step in realizing such a coding scheme, statistical characteristics of stereoscopic images and image characteristics viewed from the aspect of human stereopsis are presented. First, the possibility of data compression that exploits the cross correlation between right and left images is shown. Based on this, a method that shifts one image horizontally and subtracts it from the corresponding area of the other is proposed and evaluated. Next, it is shown that complete depth amplitude reproduction of stereoscopic images through the use of existing CRT display systems is difficult. This is due to the poor horizontal resolution of the forementioned systems even though the depth spatial frequency bandwidth of stereoscopic images can be reduced without deteriorating depth shape reproduction accuracy. Finally, a method for overcoming discontinuous depth reproduction is proposed and its effectiveness is confirmed.