虹膜定位方法研究

Research on iris location's method

简要介绍了目前具有代表性的4种虹膜定位方法:Daugman定位法、Hough变换定位法、几何特征定位法和主动轮廓线定位法,并指出了这些方法在实际应用中的优点与缺点。根据上述几种方法,提出了一种简单有效的虹膜定位法:由于瞳孔与虹膜之间的灰度差比较明显,所以先通过求图像直方图的方法找到域值点,分割出瞳孔,然后计算瞳孔的圆心位置以及半径,利用虹膜的外边缘与内边缘近似为同心圆的性质,最后用变圆模板的方法求得虹膜外半径。文中选取多组不同图像质量的虹膜图像来说明定位的效果。实验结果表明,该算法设计简单,定位效果良好。

Iris location is an essential preprocessing step in iris recognition applications. In this paper, we put forward an effective method for iris location, primarily inspired from the traditional iris location's ways. Firstly, the picture's histogram is analyzed in order to find the threshold for separating the pupil. After separating the pupil, the pupil's center and radius could be calculated. Finally, we make use of an integro-differential operator for locating the outer-radius of the iris. Experimental results indicate that the proposed method is practical.