HDTV COMPATIBLE TRANSMISSION-SYSTEM

Psychophysical measurements of vision have been used to design a compatible HDTV transmission system. A standard 525-line NTSC transmission is combined with a detail transmission in an additional half-channel of bandwidth to recreate an 1125-line HDTV image. The concept also makes possible the construction of a bichannel HDTV camera that uses progressive scanning of the high-resolution information at modest bandwidths. This camera has been demonstrated with both a standard 525-line NTSC output and an 1125-line HDTV output.