DIGITAL TELEVISION

It is now recognized worldwide that all television services, including HDTV, will eventually become digital, but there is wide disagreement about the optimum timing for transforming existing analog systems. A major driving force is the ongoing partial merging of television and digital computers in interactive multimedia services involving digital television and applications in areas like information (news), education, medical, entertainment, etc. A major target is to maximize interoperability of video services at all levels, including various resolutions, different transmission and storage mechanisms, as well as bit rates. This paper provides an overview of the current status in digital television, techniques used, future prospects, and research areas that need to be investigated. The maturity of compression techniques needed for digital video storage and transmission, and the establishment of international standards for digital television representation, like MPEG-2, have greatly contributed in this transformation. Recent developments are mentioned, including the American ''Grand Alliance'' FCC effort for digital terrestrial HDTV broadcasting, and also other efforts for digital television by cable and DBS. The concept of hierarchical multiresolution coding is also explained, and some of its techniques are briefly described.