1 Introduction
Video anomaly detection is the task of localizing anomalies in space and/or time in a video, where anomalies are simply activities that are out of the ordinary. Anomalies are also referred to as abnormalities, novelties, and outliers among other similar terms. Examples range from unattended bags at airports, to people falling down, to a person loitering outside a building. We follow the definition provided in [1],