The compatibility of HDTV sources and displays with present day television systems

Results of experiments to investigate the effect of displaying high-definition source signals on conventional 625-line displays (down-conversion) and of displaying current standard signals on high-definition displays (up-conversion) are presented. Adaptive techniques were used to calculate the up-converted signal. A 625-line camera, modified to enable it to simulate a portion of a HDTV source was used to investigate the trade-offs involved with the choice of interlaced or sequential scanning, and the use of various field frequencies. The fundamental performance of any HDTV source was investigated using a set of high-speed field stores.