title: Characterization of iris pattern stretches and application to the measurement of roll axis eye movements.
abstract: Eye movements are utilized in many scientific studies as a probe that reflects the neural representation of 3 dimensional extrapersonal space. This study proposes a method to accurately measure the roll component of eye movements under the conditions in which the pupil diameter changes. Generally, the iris pattern matching between a reference and a test iris image is performed to estimate roll angle of the test image. However, iris patterns are subject to change when the pupil size changes, thus resulting in less accurate roll angle estimation if the pupil sizes in the test and reference images are different. We characterized non-uniform iris pattern contraction/expansion caused by pupil dilation/constriction, and developed an algorithm to convert an iris pattern with an arbitrary pupil size into that with the same pupil size as the reference iris pattern. It was demonstrated that the proposed method improved the accuracy of the measurement of roll eye movement by up to 76.9%.
authors.affiliation: Dept. of Computer Science, Chubu University College of Engineering, Kasugai, Japan. te04020@isc.chubu.ac.jp
authors.forename: Junpei
authors.initials: J
authors.lastname: Nishiyama
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sakashita
authors.forename: Hironobu
authors.initials: H
authors.lastname: Fujiyoshi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hirata
mesh_terms: D000465:Algorithms; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007498:Iris / Q000033:anatomy & histology* / Q000502:physiology*; D009887:Ophthalmoscopy / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014741:Video Recording / Q000379:methods*