NURBS Warps

Standard Free-Form Deformations (FFD) built upon tensor-product B-Splines have been proved useful to model the warp between two views of a deformable surface. In this chapter, we show that the standard FFD is the affine projection of a threedimensional tensor-product B-Spline surface. We construct a new tensor-product warp relying on Non-Uniform Cubic B-Spline: the NURBS-Warp. We show that this new warp is an extension of the standard FFD that describes the perspective camera model. The parameters of this new deformation model may be estimated using one of the techniques proposed in, for instance, section 5. Our NURBS-Warp is compared to the standard FFD warp for both synthetic and real images. These experiments show that our NURBS-Warp gives better results than the other warps, especially when the perspective effects are important.

The work presented in this chapter has been first published in (33).