Intelligent monitoring of complex environments

Many countries around the world have implemented or are in the process of implementing tighter security measures in public and private places. Such measures are becoming widespread and are applied not only at government, military, and corporate facilities, but also in civilian infrastructures such as railway and bus stations, concourses, hospitals, nursing homes, playgrounds, and so forth. Stricter monitoring implies the use of a larger number of sensors, surveillance networks, and platforms, all of which generate large volumes of data that must be processed. A decade ago, surveillance systems had to deal with terabytes of video information; now we must talk of petabytes and soon higher orders of magnitude. Therefore, it is of utmost importance that we devise intelligent monitoring systems that can filter data and extract only relevant information and knowledge about the monitored scene. Such systems must implement algorithms that can automatic understand events, detect anomalous activity, generate an immediate response in emergency cases, and intelligently archive information for post-event analysis and system update. The articles in this special issue consider different aspects of the development of modern and intelligent systems for monitoring complex environments.