Iris image acquirement and preprocessing in biometrics
Xing Ming, Zhihui Li, Yuanning Liu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2006
As a biometrics, iris recognition is becoming an active topic in recent years. Due to constriction and dilation of iris sphincter muscle affected by illumination, iris images should be captured under steady illumination. The principles of our homemade iris capture device and real product are introduced first. This device can be used to capture fine iris images and store them into the computer. Due to changes of head orientation and binocular vergence at different iris acquirement time, a preprocessing method including iris location, normalization, image enhancement and rotation correction is then applied to achieve rotation, shift and scale invariance. Finally the correlation measurement is used to evaluate the performance of this processing.