Inverse Free-form Deformation for interactive UV map editing

Free-form deformation (FFD) is useful for manual 2D texture mapping in a 2D domain. The user first places a coarse regular grid in the texture space, and then adjusts the positions of the grid points in the image space. In this paper, we consider the inverse way of this problem, namely, inverse FFD. In this problem setting, we assume that an initial image-to-texture dense mapping is already obtained by some automatic method, such as a data-driven inference. However, this initial dense mapping may not be satisfactory, so the user may want to modify it. Nonetheless, it is difficult to manually edit the dense mapping due to its huge degrees of freedom. We thus convert the dense mapping to a coarse FFD mapping to facilitate manual editing of the mapping. Inverse FFD is formulated as a least-squares optimization, so one can solve it very efficiently.