Rectification with unconstrained stereo geometry

We present a linear rectiication algorithm for general, unconstrained stereo rigs. The algorithm requires the two projection matrices of the original cameras, and enforces explicitly all constraints necessary and suucient to achieve a unique pair of rectiied projection matrices. We report tests proving the correct behaviour of our method, as well as the negligible decrease of the accuracy of 3-D reconstruction if performed from the rectiied images directly. To maximise reproducibility and usefulness, we give a working, 22-line Matlab code, and a URL where code, example data and a user guide can be found. Stereo reconstruction systems are very popular in vision research and applications, hence the usefulness of a general and easily accessible rectiication algorithm.