1. A method for segmenting a small feature in a multidimensional digital array of intensity values in a data processor, the method comprising: computing an edge metric along each ray of a plurality of multidimensional rays originating at a local intensity extreme; identifying a multidimensional edge point corresponding to a maximum edge metric on each said ray; labeling every point on each said ray from said local extreme to said edge point; and labeling an unlabeled point if the unlabeled point is adjacent to a labeled point and the unlabeled point has a more extreme intensity than the labeled point and the unlabeled point is closer than the labeled point to the local extreme.