Source coding of HDTV with compatibility to TV

Gradual introduction of HDTV is considered to be important. In this paper a bit-rate reduction system is introduced which decreases the bit rate of digital HDTV from 664 Mbit/s to about 80 Mbit/s while ensuring compatibility with TV. The system is based on first subband splitting the interlaced HDTV signal into an interlaced compatible TV signal and three surplus signals. Then the compatible TV signal is coded with intraframe DCT coding whereas the surplus signals are coded with quantization variable-length coding and runlength coding.