Fig. 1.

Two image sets, a fixed image (A) and a moving image (B), were registered using image registration algorithms. Rigid image registration could not register the four sharp corners of the rectangle in the moving image into the rounded boundary in the fixed image. Deformable image registration locally deformed the four sharp corners with a different amount of deformation (or displacement). (C) The 2D deformation vector field (DVF) was displayed as blue arrows with the edge of the moving image object. The size and direction of the arrows represent the magnitude and direction of DVF. The magnitude of deformation is the largest at the corners and gradually decreases. (D) The deformed results with DVF.