Dual camera calibration for 3-D machine vision metrology

A dual-camera calibration algorithm and procedure are presented. The algorithm is based on the method of direct linear transformation and results in an overdetermined set of linear algebraic equations that can be utilized in determining the coordinate position of some identifiable feature in a scene relative to any set of orthogonal axes. Both radial and tangential lens distortions are considered in a second step of the calibration algorithm to improve the accuracy of the position sensor. Since the algorithm incorporates both types of lens distortions, it can be applied to a camera with any combinations of lenses, e.g. a lens system with a supplementary lens for close-up observations