Visual Sensor Networks

Research into the design, development, and deployment of networked sensing devices for high-level inference and surveillance of the physical environment has grown tremendously in the last few years. This trend has been motivated, in part, by recent technological advances in electronics, communication networking, and signal processing. Sensor networks are commonly comprised of lightweight distributed sensor nodes, such as low-cost video cameras. There is inherent redundancy in the number of nodes deployed and corresponding networking topology. Operation of the network requires autonomous peer-based collaboration amongst the nodes and intermediate data-centric processing amongst local sensors. The intermediate processing known as in-network processing is application-specific. Often , the sensors are untethered so that they must communicate wirelessly and be battery-powered. Initial focus was placed on the design of sensor networks in which scalar phenomena such as temperature, pressure, or humidity were measured. It is envisioned that much societal use of sensor networks will also be based on employing content-rich vision-based sensors. The volume of data collected as well as the sophistication of the necessary in-network stream content processing provides a diverse set of challenges in comparison generic scalar sensor network research. Applications that will be facilitated through the development of visual sensor networking technology include automatic tracking, monitoring and signaling of intruders within a physical area, assisted living for the elderly or physically disabled, environmental monitoring , and command and control of unmanned vehicles. Many current video-based surveillance systems have centralized architectures that collect all visual data at a central location for storage or real-time interpretation by a human operator. The use of distributed processing for automated event detection would significantly alleviate human operators from mundane or time-critical activities, and provides better network scalability. Thus, it is expected that video surveillance solutions of the future will successfully utilize visual sensor networking technologies. Given that the field of visual sensor networking is still in its infancy, it is critical that researchers from the diverse disciplines including signal processing, communications, and electronics address the many challenges of this emerging field. This special issue aims to bring together a diverse set of research results that are essential for the development of robust and practical visual sensor networks. In the first paper entitled " Determining vision graphs for distributed camera networks using feature digests " by Chen et al., the authors present a new framework to determine image relationships in a large network of visual sensors in …