基于双远心镜头的虹膜图像采集方法

Iris Image Acquisition Method Based on Bilateral Telecentric Lens

信息完整的虹膜图像可以提高不同虹膜间的差异性,有助于提升识别系统的准确性,也有利于分析虹膜纹理的细节特征。但是由于设备、环境和人为等因素的影响,采集到的虹膜图像不可避免地会出现光斑,这些光斑会造成部分虹膜信息缺失。因此,高质量的虹膜图像对整个虹膜识别系统至关重要。文中研究了完整的虹膜图像采集方法,利用双远心镜头其特殊的光学结构和较宽的景深,消除视差和畸变等由镜头带来的影响,并结合图像拼接、融合的方法得到信息完整的虹膜图像。最后将经过该系统得到的虹膜图像与未进行拼接的虹膜图像进行识别匹配的比较实验。结果表明,文中方法得到的虹膜图像有较高的匹配率,并且纹理丰富、信息完整,可以提升识别系统的有效率。

The complete information iris image can improve the othemess between different iris, which is helpful to improve the accuracy of the recognition system, and also to analyze the detail feature of iris texture. But, in virtue of the equipment, environment, man-made and other factors,the acquisition of the iris image will appear some spots inevitably which will cause the missing part of the iris informa- tion. Therefore,high quality his image is very important to the whole his recognition system. In this paper,the complete his image acqui- sition method is studied. It uses the special optical structure and the wide depth of field of the bilateral telecentrie lens, elimination of the influence of parallax and distortion caused by the lens,and applies the method of image stitching and anastomosing to get the complete iris image. Finally, the comparison test is carded out on the recognition and matching of the iris image stitching and one no stitching. Experi- mental results indicate that the matching rate of the his image obtained by the method is high, with rich texture and complete information, and the efficiency of the recognition system is also promoted.