一种新的虹膜图像预处理眼睑定位算法  

Novel Eyelid Location Algorithm in Iris Image Preprocessing

作　　者：岳学东[1] 刘洋[2] 

机构地区：[1]郑州大学物理工程学院,郑州450052 [2]中国科学院西安光学与精密机械研究所

出　　处：《光电工程》2008年第8期66-70,101,共6页Opto-Electronic Engineering

基　　金：国家自然科学基金资助项目(60605009)

摘　　要：针对眼睑边缘结构复杂、干扰因素多、定位速度慢的问题,提出了一种新的虹膜图像预处理眼睑定位算法。首先,通过大窗口平滑滤波、特定方向边缘点检测以及高阈值边缘点筛选等算法处理虹膜图像,以有效去除睫毛、眼部纹理等屋脊状边缘的干扰,快速检测出单层眼睑及双层眼睑的外边缘点集合。然后,对检测到的眼睑边缘点进行曲线拟合,获得完整的眼睑边缘曲线,完成第一次定位。最后,根据双层眼睑的内外层边缘近似平行、而且在内层眼睑边缘处出现灰度跳变这一特点,以第一次定位所得拟合曲线为模版,平行下移搜索灰度跳变位置,完成对双层眼睑的二次定位。实验表明,本文算法在保证定位准确率的基础上,定位速度得到有效提高。Referring to the complexity of the eyelid edge structure, many interferential factors and the slowness of the localization speed, large window smoothing filtering, edge points detection in special directions and high threshold edge point screening were used to reduce the interference from the eyelash, eye texture and other ridge-like edge, and the point set was acquired on the edge of the single-layer or the double-layer eyelid rapidly. And then, the curve fitting method was used to process the detected point set to acquire the continuous eyelid edge curve. The first eyelid location was completed. Finally, according to the characters that the inner and outer edge of double-layer eyelid are approximate parallel and the gray distribution changes sharply on the edge of inner eyelid, take the fitting curve acquired in first eyelid location as a template, and shift it down parallel to detect the position where gray value changes abruptly. Then the second time eyelid location was finished. The experiment shows that the location speed can be improved effectively on the basis of ensuring an high location accurate rate.

关 键 词：平滑滤波 边缘检测 曲线拟合 眼睑定位 虹膜图像 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]