@article {SHISPL,
	title = {Rotational Invariant Operators based on Steerable Filter Banks},
	journal = {IEEE Signal Processing Letters},
	volume = {13},
	number = {11},
	year = {2006},
	url = {http://users.soe.ucsc.edu/~manduchi/papers/SPpaperRV-2cols.pdf},
	author = {X. Shi and Ribeiro-Castro, A.L. and Roberto Manduchi and R. Montgomery}
}
