An iterative factorization method for projective structure and motion fromimage sequences

In this article a novel recursive method for estimating structure and motio n from image sequences is presented. The novelty lies in the fact that the output of the algorithm is independent of the chosen coordinate systems in the images as well as the ordering of the points. It relies on subspace and factorization methods and is derived from both ordinary coordinate represe ntations and camera matrices and from a so-called depth and shape analysis. In addition, no initial phase is needed to start the algorithm. It starts directly with the first two images and incorporates new images as soon as n ew corresponding points are obtained. The performance of the algorithm is s hown on both simulated and real data. Moreover, the two different approache s, one using camera matrices and the other using the concepts of affine sha pe and depth, are unified into a general theory of structure and motion fro m image sequences. (C) 1999 Elsevier Science B.V. All rights reserved.