Thin-plate spline approximation for image registration

The point-based registration technique of F.L. Bookstein (1989) can be seen as an interpolation problem. With this technique an elastic transformation based on thin-plate splines is determined which maps the source and target landmarks exactly to each other. However, in real applications the positions of the landmarks can only be determined approximately. Therefore, in this case an interpolation scheme is inadequate and should be substituted by an approximation scheme to take into account the localization errors. In this paper, the authors describe an approach for extending Bookstein's method in this direction.