Robust watermarking and affine registration of 3D meshes

We propose a robust non-blind watermarking algorithm based on direct free form deformations and applicable to smooth (organic) meshes. The algorithm does generate "low frequent" smooth deformations. The second main contribution of this paper is a registration method capable of handling affine transformations in cases where meshes do not suffer from cropping. The method is an extension of results from [1] to the 3D dimensional case. We use this method as a preprocessing step of a conventional registration algorithm (capable of handling rigid transformations plus uniform scaling). We are therefore able to automatically retrieve watermarks from copies differing from the original by one global affine transformation and of course additional polygon simplification, subdivision surfaces, uniform- or gaussian distributed noise. We present experiments on robustness of watermarks and performance of the proposed registration technique