WATSS: a Web Annotation Tool for Surveillance Scenarios

In this paper, we present a web based annotation tool we developed allowing creating collaboratively a detailed ground truth for datasets related to visual surveillance and behavior understanding. The system persistence is based on a relational database and the user interface is designed using HTML5, Javascript and CSS. Our tool can easily manage datasets with multiple cameras. It allows annotating a person location in the image, its identity, its body and head gaze, as well as a potential occlusion or group membership. We justify each annotation type with regards to current trends of research in the computer vision community. We further detail how our interface can be used to annotate each of these annotations type. We conclude the paper with an usability evaluation of our system.