Sign talk over the phone

Press, 27 July 1989, Page 13

Sign talk over the phone

A videophone system developed in Britain enables the used hand-sign conversation between hearing-impaired or deaf people over the public telephone network, the London Press Service reports. The technique is the joint work of engineers at the Martlesham Heath research laboratories of British Telecom and the engineering systems department at Essex University. The system uses an imagecoding method to produce car-toon-like images, which are datacompressed for transmission in real time via a communications modem. Equipment comprises a small video camera and an 80mm monitor housed together in a compact table-top terminal, along with an interface unit which initiates a call on the telephone network at the push of a single button, and also signals incoming calls with audible and visible warning devices. It has been known ,for some time that simplified , moving car-toon-type pictures can convey enough information for hearingimpaired people to read sign language. However, the amount of data generated has until now been too large to send over a normal telephone network at a rate high enough to show fluent motion. Engineers have now introduced feature extraction and data compression techniques in conjunction with the latest digi-tal-signal processing and modem technology. A custom-designed framestore holds four image pages, each with a resolution of 64x64 eight-bit picture elements. Images from a full TV field are filtered and processed during capture on to the page, and simultaneous access to each page enables capture and processing to take place together-