灰度分布特征的虹膜定位算法研究

Research on iris localization algorithm using gray distribution features

为克服浓密睫毛、眼睑等噪声对虹膜定位算法的影响,提出一种有效的去扰虹膜定位算法。对于虹膜的内边缘,在二值化分离瞳孔区域的基础上,利用形态学中的开运算消除噪声,并用灰度投影法定位瞳孔的圆心、半径。而对于虹膜的外边缘,则采用形态学中的闭运算去除虹膜区丰富的纹理,并设计了一个边缘检测模板,在小范围内搜索虹膜外边界的上下左右4个边界点进而确定虹膜的圆心、半径。对比的仿真实验表明:该算法不仅在计算精度和速度上都有很大提高,而且具有较好的鲁棒性。

Influenced by the noise,for example,eyelid and eyelash occlusions,current iris localization algorithms are difficult to strike a right balance between real-time quality and accuracy.Therefore, a novel iris localization method with effective noise eliminating is proposed.For the iris＇ inner edge location,morphological open is used to eliminate noise based on separating pupil region by binaryzation.Tben the pupil＇s center and radius are located accurately by gray projection.For the iris＇ outer edge location, morphological close is proposed to eliminate the rich texture within the iris area.Based on this method, an edge detection template to search four directional points within a small scope of the probable boundary is designed and thus the iris＇s centre and radius can be located.Simulation results show that, compared to the pre-algorithms, the presented scheme not only greatly improves the accuracy and the speed,but also shows good robustness.