Improving evidential quality of surveillance imagery through active face tracking

We report on a system for automatically obtaining high-resolution images of surveillance targets. The system, beginning from a framed target, uses the presence of faces as a cue to initiate a real-time active face tracking process. Using a single pan-tilt-zoom (PTZ) camera, the system tracks the target while zooming in for a closeup image of the face. The system tracks feature points on a target face, and a simple yet reliable control strategy is used in conjunction with robust target localization to guide a PTZ camera to a facial closeup of the target. We report on experiments with our system in real surveillance environments