Citywatcher: annotating and searching video data streams for smart cities applications

Digital pervasive video cameras can be abundantly found everywhere these days and their numbers grow continuously. Modern cities have large networks of surveillance cameras including CCTV, street crossings and the like. Sometimes authorities need a video-recording of some road accident (or of some other event) to understand what happened and identify a driver who may have been at fault. In this paper we discuss the challenges of annotating and retrieving video data streams from vehicle-mounted surveillance cameras. We also propose and evaluate the CityWatcher application - an Android application for recording video streams, annotating them with location, timestamp and additional context in order to make them discoverable and available to authorized Internet of Things applications.