@Article{GrigorescuPetkovWestenberg2003ieee-tip_contour,
  author =   {C. Grigorescu and N. Petkov and M. A. Westenberg},
  title =    {Contour detection based on nonclassical receptive field inhibition},
  journal =  {IEEE Transactions on Image Processing},
  year =     {2003},
  volume =   {12},
  number =   {7},
  pages =    {729-739}
}