Multiscale Representation and Analysis of Features from Medical Images

We address here the problem of multiscale extraction and representation of characteristic points based on iso-surface techniques. Our main concern is with 2D images: we analyze corner points at increasing scales using the Marching Lines algorithm. Since we can exploit the intrinsic nature of intensity of medical images, segmentation of components or parameterization of curves is not needed, in contrast with other methods. Due to the direct use of the coordinates of points, we get a representation of orbits, which is very convenient both for detection at coarse scale and for localization at ne scale. We nd that the signii-cance of corner points depends not only on their scale-space lifetime but also on their relationship with curvature innexion points.