1. An image registration system comprising: a deformation engine comprising: first logic configured to compute a flexibility model using a first region within a medical deformable image and to apply the computed flexibility model to the medical deformable image to generate a set of displacement vectors, the set of displacement vectors being configured to apply a first force to the medical deformable image; second logic configured to compute a smoothing function using the first region within the medical deformable image and to apply the smoothing function to the set of displacement vectors to create a smoothed set of displacement vectors; third logic configured to compute a transform using a second region of the medical deformable image, the transform being configured to apply a second force to the medical deformable image, the second force opposing the first force; and fourth logic configured to apply the smoothed set of displacement vectors and the transform to the medical deformable image in one of a plurality of iterations to deform the medical deformable image to match a reference image.