Automatic extrinsic camera parameters estimation for a mobile ToF camera application

Extrinsic camera parameters estimation is an important task for many assistance systems. The reconstruction of the image to world projection depends strongly on robust estimated camera parameters. Based on the used camera system, the extrinsic parameters estimation can be a complicated task, that maybe requires a lot of computing capacity. In this paper, an extrinsic camera parameters estimation procedure for a time of flight sensor, equipped on a rollator for impaired people, is presented. Effectiveness and robustness of the procedure are in the focus of the developed calibration procedure. The precision of image to world projection based on the estimated parameters is evaluated. The influence of the sensor noise regarding the measured diagonal values, e.g. depth values in the vicinity of the principal point of the camera sensor, to the ground plane is evaluated, too. Many different viewing angles as well as different height configurations of the system setup are used to evaluate the accuracy of the estimation procedure.