Non-rigid registration of medical image using α B-spline transformation

A new nonrigid registration method has been developed in this paper. In the proposed algorithm, we use αB-Spline transformation based on free-form deformation model to register images. The αB-Spline not only possesses many desirable geometrical and computational properties as B-spline, but also enhances the shape-control capability. It uses the linear singular blending technique, which is derived from the blending parameters defined at the B-spline control vertices. The volume can be transformed by changing the positions of control vertices and the value of blending parameters. We first use affine transformation to coarsely match two images, then warp the image by altering the positions of the control points, at last, adjust the values of blending parameters to change the image finely. We combine the SSD similarity measure with the regularization of Laplacian model as the cost function. Compared with that of the affine and B-sphne transformation, the result of the proposed method is better.