Advanced Television System Considerations for Compression

Many picture and signal format issues have been argued in isolation. However, in reality the quality of delivered images will be determined by the interaction of these format and processing issues throughout the entire production and delivery chain. Of particular concern is the way that compression reacts to signal and picture formats. Compression of the final image using a squeeze of two orders of magnitude forms the critical bottleneck in the delivery chain. It is this bottleneck that primarily determines potential delivered quality. — Display and channel noise considerations may initially limit or affect delivered quality. However, displays and picture delivery are likely to eventually improve to the point where compression quality determines the appearance of the end result. — Compression is a set of processes for coding an image. These processes seek to discard data without undue damage to picture quality. Each process is affected by different issues, yet all of the processes react together to create the final result. In addition, other processes in the production chain prior to compression will interact with the compression processes. — The author and his company have been very active in exploring layered compression based upon MPEG-2. For many high resolution formats, a layered compression system will outperform a non-layered system. Further, layered compression has the advantage of substantially reducing the cost of decoders for the more affordable class of displays. — Although there is vigorous debate about television formats and signal practices, there is a strong desire to prepare and distribute high quality pictures. This paper attempts to identify the practices which lead to high quality pictures, as well as to identify those practices which hinder picture quality. The discussion further attempts to describe a way of conceiving digital video systems which leads to flexibility, as well as discussing those practices which limit and restrict the use of the advanced television video signals. The author has long been an advocate of interoperability and flexibility. We will take a fresh look at high definition video signals and practices from this perspective.

Published

1998-10

Content type

Original Research

DOI

10.5594/M00277

ISBN

978-1-61482-929-4