Stereo calibration from correspondences of OTV projections

Stereo images have to be calibrated before stereo vision can recover three-dimensional information of the imaged scene. Position constraints over image point correspondences are traditionally used to solve the calibration problem. A method is described that uses angle constraints over correspondences of a particular type of image features, the projections of orthogonal trihedral vertices (OTV), for calibration. Computations of the rotation matrix and the translation vector are separable and the method has a closed-form solution. It also requires correspondences of only two vertex projections at minimum to recover all the transformation parameters which are recoverable from a stereo image pair. Extensive experimental results, including those on real images, are presented and they show that use of angle constraints is generally more accurate than position constraints alone