Searching in space and time: a system for forensic analysis of large video repositories

Abstract

The use of surveillance cameras to monitor public buildings and urban areas is becoming increasingly widespread. Each camera delivers a continuous stream of video data, which, once archived, is a valuable source of information for forensic analysis. However, current video analysis tools are primar- ily based on searching backwards and forwards in time at a single location (i.e. camera), which does not account for events or people of interest that change location over time. In this paper we describe a practical system for tracking a target backwards and forwards in both space and time, ef- fectively following a feature of interest as it moves within and between cameras in a surveillance network. This pro- vides a video analysis tool that is target-centred rather than camera-centred, and thus allows rapid access to the footage that matters for forensic analysis.