Takanori Hisanaga

High-resolution color image transmission scheme over ATM network

This paper describes a system that attaches a color copier to ATM network as a full color image input and output terminal. For still image tranmission, both high quality of the transmitted image and high transmission throughput are required. To achieve this goal, a new image transmission scheme for ATM network is proposed. A design and implementation of a protocol based on the scheme, an image tranmission system and evaluation of its throughput are also discussed. The scheme is based on retransmission with allowing limited number of errors for one block of data. Instead of retransmission, the scheme employs concealment for the cases of small number of errors. Concealment is an error correction method using the redundancy of image data to improve image data quality. The system based on this scheme demonstrated throughput as almost high as the maximum bandwidth of ATM, 156Mbps, with keeping image quality better than 40dB. It is proved that a relaxation of retransmission condition by concealment is effective to achieve high throughput under average ATM netowrk transmission quality. The system can provide 20 pages per minute transmission throughput for 16 pixels/mm resolution full color images.