Approximate orientation steerability based on angular Gaussians
@Article{yu01ieeetip,
  author = 	 {W. Yu and K. Daniilidis and G. Sommer},
  title = 	 {Approximate orientation steerability based on angular Gaussians},
  journal = 	 {IEEE Transactions on Image Processing},
  year = 	 2001,
  volume =	 10,
  number =	 2,
  pages =	 {193-205},
 }