On the Integrated Calibration of a Digital Stereo .. Vision System

A fixed base digital stereo-vision system is a powerful tool for positioning objects in 3-dimensions without control in object space. It can be integrated in a vehicle together with GPS and inertial systems to collect spatial information while driving at highway speeds. In this paper we discuss the integrated calibration of the stereo-vision system using a simultaneous, constrained adjustment of multiple image-pairs. It is based on the wellknown bundle technique which is extended by the following constraints and unknown parameters: the base between the two cameras is measured externally and jixed in the adjustment; as the relative orientation does not change it must be the same for all imagepairs. Furthermore, the interior orientation is left open and additional parameters compensate for lens distortions. A testjield of control points is photographed with the digital stereo-vision system. It serves both as control for the bundle solution and as a reference for an independent evaluation of the accuracy of spatial positioning.