Experiments on video teleconferencing algorithms at 56 kilobits/sec

The design of a 56 kilobits/sec. (kbps) coder to transmit monochrome video signals should include several bit rate reduction techniques. In this work, some already existing techniques are simplified and combined with a new edge detection algorithm to produce a simple but efficient coder. Both signal-to-noise ratios and perceptual comparisons indicate that, without loss in performance, significant reduction in transmission data rate can be accomplished by properly recognizing the information bearing parts of an image.