Abstract :
The paper has reviewed a number of quality issues and has emphasised the need to devise objective measures of performance which apply to compression processes, since those adapted from analogue are often inappropriate. With DTH broadcast systems, means exist to avoid the major pitfalls of quality variations; several channels of programming in multiplex gives broadcasters flexibility to trade choice for quality. If picture redundancy is over-exploited, there will be an erosion of quality during programme production. It is important for the future that precipitate steps are not taken until the accumulation processes are better understood; high bit rate and modest levels of compression should be employed in studios. It might also be wise to use a variety of systems to assist in smoothing defects. It is fortunate that temporal processing is inappropriate in studios because the use of high ratio compression needs to be exploited to the full in the final stage to the viewer
