Improving Geodesic Invariant Descriptors through Color InformationComputer Vision and Computer Graphics. Theory and Applications

Geodesic invariant feature (GIH) have been originally proposed to build a new local feature descriptor invariant not only to affine transformations, but also to general deformations. The aim of this paper is to investigate the possible improvements given by the use of color information in this kind of descriptors. We introduced color information both in geodesic feature construction and description. At feature construction level, we extended the fast marching algorithm to use color information; at description level, we tested several color spaces on real data and we devised the opponent color space as an useful integration to intensity information. The experiments used to validate our theory are based on publicly available data and show the improvement, both in precision and recall, with respect to the original intensity based geodesic features. We also compared this kind of features, on affine and non affine transformation, with SIFT, steerable filters, moments invariants, spin images and GIH.