Non-Rigid Registration With Free-Form Deformation Model of Multi-Level Uniform Cubic B-Splines: Application to Image Registration and Distortion Correction of Spectral Image Cubes

In spectral imaging, spatial and spectral information of an image scene are combined. There exist several technologies that allow the acquisition of this kind of data. Depending on the optical components used in the spectral imaging systems, misalignment between image channels can occur. Further, the projection of some systems deviates from that of a perfect optical lens system enough that a distorsion of scene content in the images becomes apparent to the observer. Correcting distortion and misalignment can be complicated for spectral image data if they are different at each image channel. In this work, we propose an image registration and distortion correction scheme for spectral image cubes that is based on a free-form deformation model of uniform cubic B-splines with multi-level grid refinement. This scheme is adaptive with respect to image size, degree of misalignment and degree of distortion, and int tha sense is superior to previous approaches. We support our proposed scheme with empirical data from a Bragg-gratin based hyper-spectral imagef, for which a registration accuracy of approximately one pixel was achieved.