The high-definition television (HDTV) system was developed in the 1980s.  It uses 1125 lines and a wide-screen format, providing a significantly clearer picture than the traditional 525- and 625-line television screens.  Each line in HDTV also contains more information than normal formats. HDTV is transmitted using digital technology. Because it takes a huge amount of coded information to represent a visual image, engineers believe HDTV will need about 30 million bits (ones and zeros of the digital code) each second-data-compression techniques have been developed to reduce the number of bits that need to be transmitted. With these techniques, digital systems need to continuously transmit codes only for a scene in which images are changing; the systems can compress the recurring codes for images that remain the same (such as the background) into a single code. Digital technology is being developed that will offer sharper pictures on wider screens, and HDTV with cinema-quality images.
            Engineers are also working on making HDTV compatible with computers and telecommunications equipment so that HDTV technology may be applied to other systems besides home television, such as medical devices, security systems, and computer-aided manufacturing (CAM).

"Television," Microsoft(R) Encarta(R) 98 Encyclopedia. (c) 1993-1997 Microsoft Corporation. All rights reserved.


 
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Last Updated: May 19, 1999
Created by Diana Waxman , Jessica Bureau & Greg Roeberg