Abstract: A method for reconstructing surfaces and analyzing surface and volume representations of the shape of an object or structure corresponding to image data, in which the structure has been modeled as one or more physically distinct compartments. The characteristics of a compartmental model are specified in terms of the material types contained in each distinct compartment and in terms of the nature of compartmental boundaries as defined by the image data. An image model that includes scalar or vector image intensity functions for each material type and for each boundary type defined by the image data is specified. Gradient functions that characterize each boundary type and some compartmental regions are specified. A set of probabilistic volume representations of the location of different compartments and the location and orientation of compartmental boundaries is generated.