Error-resilient video coding and application to telemedicine
Digital imagery and video are a vital part of medical consultation and diagnosis. A telemedicine program linking international hospitals improves patient care, promotes more rapid diagnosis, and may hasten improved survival rates for children with cancer. However, in many developing countries and in rural and remote areas, reliable wired communications lines are not available, in which case telemedicine needs to be conducted over wireless transmission media. Although capable of providing the user with considerable mobility, the inherent noise-laden properties and reduced bandwidth requirements of wireless communication pose challenging design problems when compressed digital video is transmitted. This paper presents a low bit-rate error-resilient channel-optimized coder for the transmission of video over the binary symmetric channel. The proposed coder uses a channel-optimized trellis-coded quantization (COTCQ) stage that is designed to optimize the video coding based on the channel characteristics. The resilience to channel errors is obtained by optimizing the coder performance only at the level of the source encoder with no explicit channel coding for error protection. The objective of this effort is to design, test, and implement on real-world wireless systems, error-resilient, low bit rate, video coding systems for the reliable transmission of medical imagery and video over noisy wireless channels. Simulation results show that our coder can produce a visually pleasing rendition of the original signal even at high channel error rates.