基于二次圆周补偿的虹膜边界定位方法

Iris Boundary Localization Method Based on Double Circular Compensation

为提高虹膜定位的准确性与实时性,提出了基于二次圆周补偿的虹膜边界定位算法。所提算法以近似半径补偿与近似圆心补偿为核心,对虹膜内及其外边缘进行定位。定位内边界时,利用最小灰度均值法进行粗定位,并在提取内边缘图像后采用近似圆心补偿法进行细定位;定位外边界时,采用近似半径补偿法进行粗定位,再根据近似圆心补偿法进行细定位。实验结果表明,从CASIA虹膜库中随机选取了2000张不同虹膜图像进行了验证,算法平均定位时间为0.29s,定位准确率为98.1%。所提算法在准确度与实时性方面都较对比方法有所提高。

In order to improve the accuracy and real-time performance of iris location, an iris boundary location algorithm based on double circular compensation is proposed. The approximate radius compensation and approximate circle center compensation are used as the core to locate the inner and outer boundary of the iris by the proposed algorithm. When locating the inner boundary, the minimum gray average method is used to perform coarse localization, and the approximate circle center compensation method is used for locating the inner boundary exactly after extracting the inner boundary images. When locating the outer boundary, the approximate radius compensation method is used to perform coarse locating, and the exact locating is performed by the approximate circle center compensation method. Experimental results show that 2000 different iris images from CASIA for verification are randomly selected. The average locating time of the algorithm was 0.29 s, and the locating accuracy rate is 98.1%. The proposed algorithm is more accurate and faster than the contrast method.