Front propagation and level-set approach for geodesic active stereovision

Abstract

A framework for matching complex 2D planar curves lying at the intersection of a 3D virtual plane and the 3D scene being observed using a weakly calibrated stereo system, is presented in this article. Using an energy minimization based approach, we reformulate this stereo problem as a front propagation problem. The Euler Lagrange equation of the designed energy functional is first derived and the flow minimizing the energy is obtained. The curves to be matched are modelized as geodesic active contours [2, 8, 7] evolving toward the minimum of the designed energy, under the influence of internal and external correlation image dependent forces. This original scheme may be viewed as a geodesic active stereo model which basically attract the given curves to the bottom of a potential well corresponding to pixels having similar intensities. Using the level set formulation scheme of Osher and Sethian [9], complex curves can be matched and topological changes for the evolving curves are naturally managed. The final result is also relatively independent of the curve initialization. Promising experimental results have been obtained on various real images