Privacy protection by concealing persons in circumstantial video image

A circumstantial video image should convey sufficient situation information, while protecting specific person's privacy information in the scene. This paper proposes a system which automatically identifies a person by face recognition, tracks him or her, and displays the image of the person in modified form such as silhouette with or without name, or only name in characters (i.e. invisible person). A subjective evaluation experiment was carried out in order to know how people prefer each modified video image either from observer or subject viewpoint. It turned out that the silhouette display with name list seems to be most appropriate from the balance between protecting privacy and conveying situation information in circumstantial video image.