  We rephrase the problem of 3D reconstruction from images in terms of
intersections of projections of orbits of custom built Lie groups actions. We
then use an algorithmic method based on moving frames "a la Fels-Olver" to
obtain a fundamental set of invariants of these groups actions. The invariants
are used to define a set of equations to be solved by the points of the 3D
object, providing a new technique for recovering 3D structure from motion.
