Complete and Stable Projective Harmonic InvariantS for Planar Contours Recognition

Planar shapes recognition is an important problem in computer vision and pattern recognition. We deal with planar shape contour views that differ by a general projective transformation. One method for solving such problem is to use projective invariants. In this work, we propose a projective and parameterization invariant generation framework based on the harmonic analysis theory. In fact, invariance to reparameterization is obtained by a projective arc length curve reparameterization process. Then, a complete and stable set of projective harmonic invariants is constructed from the Fourier coefficients computed on the reparameterized contours. We experiment this set of descriptors on analytic contours in order to recognize projectively similar ones.