Robust Surface Matching for Registration

The ability to accurately register images of patients taken at different times is very important in many medical applications. In most cases, the main reason for registration is to measure changes, and therefore any automatic registration algorithm employed for this task must be able to cope when there are significant differences in the images. In this paper a new algorithm is presented which enables accurate surface registration by using a robust matching algorithm to calculate correspondences for all points along with a measure of reliability of the correspondence. The reliability is tested by moving the point of interest and seeing if it always matches to the same point. In this way, a scatter of “tentative corresponding points” is generated, and a corresponding point and reliability are calculated from the geometric distribution of these points. This new algorithm is compared with two others. Experiments show that our algorithm is more accurate, consistent and converges faster than the others.