1. A method of segmenting a digitized image, comprising the steps of: providing a digitized image comprising a plurality of intensities corresponding to a domain of points on an N-dimensional grid; defining a weight between each pair of adjacent points in the image based on the intensity difference of each said point pair; marking a subset of points in said image wherein each marked point is marked with one of a plurality of labels; determining the probability that an unmarked point should be marked with one of said plurality of labels using a multigrid method that uses a restriction operator to map said provided image to a coarse-level gird, and a prolongation operator to map said coarse-level image back to a fine-level grid, wherein said restriction operator is an adjoint of said prolongation operator, and wherein a fine-level segmentation is a prolongation of a coarse level segmentation.