“…This is followed by a deformable transformation which has more degrees of freedom as well as higher capability to describe local deformations. There is a wide range of classical variational methods to account for local deformations such as diffusion models [4], total variation models [7], [8], fluid models [5], [6], elastic models [24]- [26], biharmonic (linear curvature) models [27], [28], mean curvature models [29], [30], optical flow models [3], [31], [32], fractional-order variation models [33], [34], non-local graph models [35]- [37], etc. The free-form deformation (FFD) methods based on B-splines model [38], [39] are able to accurately model global and local deformations with fewer degrees of freedom parameterized by control points.…”