Hierarchical coding of digital television

If the same digital television signal is used for multiple resolutions, bit rates, or transmission and storage mechanisms, then hierarchical coding offers several advantages. The FCC has decided to adopt the "main profile" of MPEG-2 for the video representation of the signal that will be used in the North American terrestrial broadcasting of HDTV. The article examines the tradeoffs of using hierarchical coding and provides an overview of possible applications and existing techniques, with emphasis on the scaleable profiles of MPEG-2, in particular the technique of spatial domain scalability.<<ETX>>