An HD (high-definition) upconverter, also known as a digital television ( DTV ) upconverter, is a device that converts the digital data on a DVD to a format that can be viewed directly on a high-definition television ( HDTV ) receiver without intermediate conversion to an analog signal. The HD upconverter digitally enlarges each frame to HD resolution. Some HD upconverters can also convert the frame rate of 35-mm movies to the frame rate of HDTV, so flickering does not occur when the movie is viewed on the HDTV receiver.
HD downconverter (high-definition downconverter)
An HD (high-definition) downconverter is a devi...(WhatIs.com)
DVD is an optical disc technology with a multi-gigabyte ( GB ) storage capacity on a disc that is the same size as a compact disc ( CD ) of the type used for audio reproduction and computer storage. HDTV is a digital television display technology that provides image quality similar to that of 35-mm movies, and sound quality similar to that of a digital audio CD.
Conventional DVD players are designed for standard-definition TV receivers. Prior to the introduction of HD upconverters, in order to view the contents of a DVD on a digital HDTV receiver it was necessary to convert the image to analog format, then convert it from standard resolution (480 lines per frame) to HD resolution (720 or 1080 lines per frame), and finally convert the HD analog signal back to digital format. The HD upconverter eliminates the intermediate steps, resulting in an image that is relatively free of blurring, aliasing, and conversion noise. Some high-end DVD players have built-in HD upconverters. HDTV broadcasters have expressed interest in HD upconverters, because they facilitate the conversion of standard-definition programs to HD format for transmission to HDTV end users.
Also see HD downconverter , which converts HDTV video to standard-definition video for viewing on convention TV receivers or computer monitors or to record HDTV video on DVDs.