Low Data-Rate Video Conferencing
Michele Covell, Jae S. Lim · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1986
A feasibility study has been completed on a narrow-band video conferencing system. Gray-scale images are converted to bi-level images and further processed to remove inconsistencies within the mappings. Ordered run-length coding of difference frames is used to update the areas of the image that are most likely to change and to be perceptually important first. Sequences of 15 (128 x 120) bi-level frames/s have been successfully transmitted at rates hard-limited at 19.2 kbits/s.