DCT coding of stereo images for tele-presence

Stereo imaging systems offer unique solutions to certain applications in the defense/aerospace community. Stereo imaging in the reconnaissance mission of unmanned air vehicles (UAVs) and unmanned ground vehicles (UGVs) offer tele-operation, tele-presence, and object positioning. With this use of a passive imaging sensor system comes a high data collection rate. For real-time operation, the data collected must be transmitted to a remote location. Image compression techniques can be utilized to reduce the transmission bandwidth and/or storage space requirements of the stereo pair. This paper develops image compression techniques specific to stereo imaging and compares performance with non-stereo methods. Disparity compensated residual image coding exploits the redundancy between the two images in a stereo pair. Stereo residuals possess special features that can be exploited within a DCT image coding framework. Use of these features results in several dB of performance enhancement across a range of scene types. This approach provides its best performance below 0.75 bits/pixel bit rate for 8-bit gray scale imagery and below 2 bits/pixel for 24-bit color imagery.