Anonymous surveillance

Video surveillance is a very effective tool of surveillance that enables a single security agent to monitor wide areas. However, it compromises the privacy of the individuals. There have been attempts to obfuscate face and silhouette regions of the images to hide the identity of individuals. We recognize that in traditional surveillance systems, the viewer generally has sufficient contextual knowledge about location of the camera, time, and activity patterns; which can lead to identity leakage even when the visual cues (face and appearance) are not present. In this way, the viewer can relate the identity of individuals to the sensitive information in the video causing privacy loss. In order to provide robust privacy preservation, the context knowledge needs to be decoupled from the video; however, human monitoring of the videos is also necessary for the assessment of the situation. In this paper we propose anonymous surveillance framework that decouples the contextual knowledge and video to the minimal extent required for situation assessment. The experimental results confirm that the proposed framework is very effective in protecting the privacy, yet does not affect much of the surveillance utility of the data.