COMPLETE CALIBRATION OF A STEREO PHOTOGRAMMETRIC SYSTEM THROUGH CONTROL POINTS OF UNKNOWN COORDINATES

This paper presents a new method for calibrating a video 3D stereo-pho togrammetric system. The external parameters and the focal lengths of the cameras are determined from the epipolar constraint and the princi pal points are computed through the minimisation of a cost function ca rried out through an evolutionary optimisation. The method has been ma de more robust with a deterministic annealing procedure of the search region amplitude. Calibration is carried out by moving a rigid bar, ca rrying two markers on its extremities, inside the working volume. The distance between the two markers is the only measure required. Tests o n real data are reported which show that the obtained accuracy is comp arable to the one achieved calibrating with control points of known 3D coordinates. (C) 1998 Elsevier Science Ltd. All rights reserved.