Geometrical image features like edges and ridges in digital images may be extracted by convolving the images with appropriate derivatives of Gaussians. The choice of the convolution operator and of the parameters of the Gaussian involved de nes a speci c feature image. In this paper, various feature images derived from CT and MR brain images are de ned and tested for usability and robustness in a correlationbased two and three dimensional matching algorithm. A number of these feature images is shown to furnish accurate matching results. The best results are obtained using gradient magnitude edgeness images.
J. B. Antoine Maintz, Petra A. van den Elsen, Max