Computing depth, shape and motion using invariants and incidence algebra

The paper presents a geometric approach for the reconstruction of shape and motion using projective invariants as function of the trifocal tensor. We compute first the projective depth using groups of three uncalibrated cameras of an image sequence and then initialize the join image matrix which can be then decomposed into a 3D shape and motion by means of SVD. Experiments using real images show the the value of the approach. Using the algebra of incidence relations of the geometric algebra the 3D reconstruction was further improved