Abstract: A method includes obtaining a first image, obtaining a second image, determining a deformation field using the first and second images, and determining a transformation matrix using the deformation field. A computer product having a set of instruction, an execution of which causes a process to be performed, the process comprising determining a deformation field using first and second images, and determining a transformation matrix using the deformation field. A system includes a computer-readable medium for storing a first image and a second image, and a processor configured to determine a deformation field using the first and second images, and determine a transformation matrix using the deformation field.