Japanese engineers at Nippon Hoso Kyokai"s Science and Technical Research Laboratories showed off their most recent work with the development of Super Hi-Vision, a system they hope will eventually replace HDTV. A SHV picture is made up of 4,320 horizontal picture lines and 7,680 vertical lines (equivalent to 16 tiled HDTV screens). In the year since it was last demonstrated, the company has moved away from multiple sensors and has developed a single image sensor for use in TV cameras that can shoot an entire SHV screen. A prototype SHV camera fitted with the sensor was set up about 3 meters away from a scene that included a newspaper. It was possible to read the stories printed on the newspaper on a monitor displaying the image – an undertaking that would be difficult on today"s high-definition systems. The sensor is monochrome and NHK says a color image is possible by simply using three in a camera, one for each primary color.
An uncompressed SHV signal has a bit-rate of 24Gbps – since it can"t be broadcast, the problem falls onto the task of real-time encoding and decoding of such a high-bandwidth signal. NHK and Fujitsu Limited have solved the issue by linking 16 encoders in parallel and essentially compressing the SHV signal to around 1/200th of its size using MPEG-4 AVC/H.264 compression. The result is a Super Hi-Vision image of 128Mbps, which is still about six times the bandwidth of today"s high-definition broadcasting. Right now the encoder system stands almost as tall as a person and requires a similarly large unit on the reception end. Engineers will have to shrink this into a handful of chips before it"s ready for a television set. NHK isn"t saying when Super Hi-Vision services might begin.