一种有效的指纹图像方向滤波增强算法 *

方向滤波是沿着指纹纹线方向滤波的方法。一种方向滤波算法的有效性主要依赖于指纹图像方向估计的准确性和滤波模板构造的合理性。首先利用对低质量指纹图像鲁棒性较高的掩膜法估计点方向 ,并将点方向转换为块方向 ;然后使用八个方向的平滑滤波模板和锐化滤波模板 ,对指纹图像滤波进行增强 ;最后对增强后的指纹图像二值化。通过对 FVC2000指纹数据库 DB2中的指纹图像作增强处理 ,表明该算法增强效果较好。

Effective fingerprint image orientation filter enhancement algorithm

Orientation filter is a method that filters the fingerprint image along ridge orientation. The effectiveness of an orien-tation filter enhancement algorithm mainly depends on the estimate accuracy of fingerprint image orientation and the design ra-tionality of filter template. This paper firstly used mask method that was robust to the poor quality fingerprint images to estimate the pixel orientations and then changed the pixel orientations to the block orientations. Secondly, enhanced fingerprint images by new proposed 8 orientations smoothing filter templates and sharpening filter templates. At last, obtained binary image after enhancement process. Experiment results for fingerprint images in DB2 of FVC2000 fingerprint bases show that the proposed method can make good enhancement effect.