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%N 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 the image; associating a probability potential with each unmarked point; and using a multigrid method to solve for the probability potentials for each unmarked point, wherein a restriction operator for the image is applied to an (N− 1 )%(N−1) image wherein each image weight is treated as a function of an adjoining point for application of the restriction operator, wherein said restriction operator determines weights of a coarse level grid.