说明：  基于二维小波变换和方向向量，提出一种新的虹膜特征提取方法。该方法的基本思想是考虑虹膜纹理的 灰度变化，对于多层小波分解后的低频分量，分别求其在4个方向上的方向向量，最后形成虹膜码。测试结果表明，该方法能 有效地提高虹膜的识别率，且算法简单、快速。
(The basic principle of the method is as follows.In view of iris textural intensity variation,for the low- frequency components of multi-resolution decomposition,directional vector along four directions is obtained,and iris code is formed in the end.According to test,the algorithm can enhance iris recognition rate.Furthermore,algorithm is simple and fast. )