title: Robust measurement of ocular torsion using iterative Lucas-Kanade.
abstract: We present a new method to measure ocular torsion using Lucas-Kanade method. After pixels of iris annulus around a pupil have been converted into Cartesian coordinates, 30 features on the iris was selected then the features were tracked using the iterative Lucas-Kanade algorithm to calculate torsional shift. The results show that a precision of the method is higher than those measured by a conventional cross-correlation and by a template matching method. The suggested method showed 0.03 degrees mean error with 0.15 degrees maximum error. Particularly, the method was robust to change of pupil size and misalignment of pupil location. Processing time was also fast enough to be implemented in a real-time system.
authors.affiliation: Interdisciplinary Program of Medical and Biological Engineering Major, Seoul National University, Seoul, Republic of Korea.
authors.forename: Inbum
authors.initials: I
authors.lastname: Lee
authors.forename: Byunghun
authors.initials: B
authors.lastname: Choi
authors.forename: Kwang Suk
authors.initials: KS
authors.lastname: Park
mesh_terms: D000465:Algorithms; D005133:Eye Movements / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D007723:Korea; D012680:Sensitivity and Specificity; D014102:Torsion Abnormality