TV Bandwidth Compression
Paul A. Wintz, J. B. Wilson, Ernie Schmidt · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1975
There are three possibilities for reducing the bandwidth of a Television signal: (1) reduce the temporal resolution by transmitting less than 30 frames per second; (2) reduce the spatial resolution by coding fewer than all of the picture elements in the frames transmitted; (3) reduce the spatial redundancy in the remaining picture elements.