Engineers at the British Broadcasting Corporation have come up with a technique for digitally enhancing television signals so that four times as much picture information can be sent over the present bandwitdth: the Beeb’s Digitally Assisted TeleVision technique isolates parts of the picture that are not changing and stores them in memory in the set, and determines the direction of moving objects so that the intermediate positions can be interpolated from memory, so that the full signal needs to be transmitted only 12.5 times a second instead of 50 times, and can thus carry four times the picture data; new or enhanced television sets will be required to receive the DATV signal, which the BBC sees as the basis of subscription services.
