Ill-posed medicine—an introduction to image registration

Image registration is the process of aligning two or more images of the same
scene taken at different times, from different viewpoints and/or by different
sensors. Image registration is a crucial step in imaging problems where the
valuable information is contained in more than one image. Here, spatial
alignment is required to properly integrate useful information from the separate
images. It is the goal of this paper to give an overview on modern techniques in
this area. It turns out that the registration problem is an inverse problem which
does require a sound regularization and the use of proper models. Also, the
numerics have to be done with great care. We will comment on these issues
and supplement it by real life examples.