1. A method for artery-vein separation and vessel modeling wherein all of the following steps are performed by a computer, comprising: receiving three-dimensional image data indicative of vessels; visualizing the received image data; selecting seed points on the vessels from the visualization; smoothing the image data with a non-linear filter responsive to curvature information of the data; initiating a deformable model for each selected seed point; modulating the propagation of each deformable model in accordance with at least one of local and global statistics; growing an interconnected region for each model, where each model competes against a neighboring model for classifying new points in its own region until convergence; detecting a collision when a plurality of deformable models collide during propagation; and outputting an indication of artery or vein in accordance with the interconnected region for each model.