Signal processing and bandwidth compression techniques

HDTV pictures are originated, in the Eureka system, using a 1250 line television standard. The bandwidth required by the HDTV source signal, including its colour components, is of the order of 30-40 MHz. Unfortunately the bandwidths of the available distribution media; satellite channels, cable, VCR and videodisc are unlikely to exceed 10-11 MHz. It is clear therefore, that a bandwidth reduction of about a factor of four is required in order to deliver HDTV to the domestic audience. This paper describes the results of research work carried out within the Eureka cooperative project in order to develop a MAC compatible HDTV bandwidth reduction system. The signal produced by this system is termed HDMAC (high definition MAC). Two aspects of this system, digitally assisted television (DATV) and motion compensation, are emphasised in particular. These aspects are instrumental in closing the gap between received picture quality and that available in the television studio, whilst at the same time, allowing a practicable decoder in the domestic receiver