Collective calibration of active camera groups

Until recently, traditional approaches to the task of camera calibration have relied on the use of accurate grid patterns, or strategically placed targets. Such approaches can prove time consuming and often require expert supervision. For ambient intelligence type applications, it is unwise to rely on the consistency of camera positions and orientations; consequently a fully autonomous camera calibration procedure is preferred. In this paper we present an auto-calibration system for the estimation of the extrinsic properties of active cameras lying within indoor, self-observable groups. Neither prior knowledge of camera locations, nor a calibration-pattern is required, just a few basic parameters concerning the physical appearance of the cameras. Groups of active cameras can be calibrated within minutes, by exploiting their precise control mechanisms. As no supervision is required, camera deployment configurations can be changed or new cameras added easily.