RELATIVE ORIENTATION REVISITED

Relative orientation is the recovery of the position and orientation of one imaging system relative to another from correspondences among five or more ray pairs. It is one of four core problems in photogrammetry and is of central importance in binocular stereo as well as in long-range motion vision. While five ray correspondences are sufficient to yield a finite number of solutions, more than five correspondences are used in practice to ensure an accurate solution with least-squares methods. Most iterative schemes for minimizing the sum of the squares of weighted errors require a good guess as a starting value. The author has previously published a method that results in the best solution without requiring an initial guess [J. Opt. Soc. Am. A 4, 629 (1987)]. An even simpler method is presented here that utilizes the representation of rotations by unit quaternions.