Image registration and distortion correction in ion microscopy.

We present a method whereby the geometric registration of a series of ion microscopic images is performed by applying a two-step procedure. After applying a global linear transformation that corrects for geometric differences, a non-linear elastic transform is used in order to match local properties and structures of the images. Transformation parameters are computed on the basis of shape-specific points in the images. Distortion correction is achieved by relating ion images to the optical image of the same field and by using the two-step algorithm to register the images. This methodology is evaluated on synthetic misaligned objects and on thyroid tissue images.