ISEQL, an Interval-based Surveillance Event Query Language

The authors propose ISEQL, a language based on relational algebra extended by intervals for detecting high-level surveillance events from a video stream. The operators they introduce for describing temporal constraints are based on the well-known Allen's interval relationships and we implemented on top of a PostgreSQL database system. The semantics of ISEQL are clearly defined, and the authors illustrate its usefulness by expressing typical events in it and showing the promising results of an experimental evaluation.