Generating skeletons and centerlines from the medial axis transform

An algorithm for generating connected skeletons of objects in binary images is described. Three main properties of the algorithm are that (1) it is noniterative, taking a fixed number of passes through the image to produce the skeleton regardless of the width of the objects; (2) it is based on a distance transform that uses a good approximation to the Euclidean distance, giving skeletons that are well-centered and robust with respect to rotation; and (3) the skeletons it produces are connected. In addition, the skeletons are thin and allow the objects to be nearly reconstructed. The algorithm can also be run in a mode to produce centerlines, a connected approximation to the skeleton that is less sensitive to border noise and that is useful in image analysis applications.