Fast Non-Rigid Image Registration Using Viscous Fluid Model and B-Spline

Viscous fluid based non-rigid registration algorithm is an appropriate method for registering objects with large-scale difference. The core component of the algorithm is to solve the fluid partial differential equations. Usually, iterative methods, such as successive over-relaxation, are employed to obtain the solution, but the computational complexity is very tremendous. To reduce the complexity, a fast method based on fluid model combined with B- spline is presented. Firstly, B-spline is used to model the velocity fields, so that the large number of unknowns are reduced to fewer B-spline coefficients; Secondly, by use of some special attributes of B-spline and fast Fourier transform(FFT), direct inversion for the B-spline coefficients are deduced. Experimental results show that our new method is not only suitable for the large-scale image deformation but also amounts relatively lower computational costs.