Lef3a: Pupil segmentation using Viterbi search algorithm

A non-circular pupil segmentation approach using Viterbi path research is presented. Around the circle approximation of the pupil, a large region of gradient is produced radially. An enhancement step is used in order to remove outliers from the gradient image. A Viterbi algorithm is applied to find the contour that maximizes the gradient value along a connex contour. Our method which we called Lef3a (a snake that lives in Tunisian desert) is compared to three state of the art methods: a circular detector, an elliptical detector and a Snake detector. The two first methods are developed by our team; the last method is an external work based on Daugman´s published method. We will show some segmentation results on non circular pupils, and we will compare the performance of all segmentation methods coupled with a standard iris coding and matching process on Notre Dame Database and our private database. Finally all methods are compared in terms of time processing.