A direct closed-form solution to general relative orientation of two stereo views

Recovering the relative geometry of two perspective stereo images is a clas sical problem in photogrammetry and also a basic problem in computer vision . General relative orientation refers to recovering five relative orientati on parameters and two principal distances from pure image measurements. Thi s paper presents a new direct closed-form solution to this problem. The app roach recasts the explicit stereo coplanarity equation into an implicit for m whose coefficients are solvable via a direct solution from the image meas urements. Two principal distances, the relative baseline vector and rotatio n of two images are then solved successively in closed-form from these coef ficients. This direct closed-form solution is useful not only in real-time implementation of stereo vision, but also for providing the approximate val ues of unknown geometric parameters to high-precision photogrammetry, as we ll as for direct functional analysis of error propagation. (C) 1999 Academi c Press.