A Lie group approach to steerable filters
@Article{michaelis95prl,
  author = 	 "M. Michaelis and G. Sommer",
  title = 	 "A {L}ie group approach to steerable filters",
  journal =	 "Pattern Recognition Letters",
  year =	 1995,
  volume =       "16",
  pages =        "1165--1174"
}