一种改进的指纹图像细化算法

在自动指纹识别系统中，细化占有重要的地位，现有的指纹细化算法存在很多问题，如细化不彻底、纹线吞噬、骨架偏离纹线中心等。对快速细化算法和改进的OPTA细化算法进行了分析和研究，指出这两种算法在指纹纹线和分叉点处图像细化不彻底等缺陷。同时将两种细化算法有机结合，设计了一组改进的细化模板，提出了一种新的细化算法。实验结果证明：该算法与传统的细化算法相比没有破坏纹线的连接性，不会引起纹线的逐步吞食，又保护了指纹的细节特征。而且该算法运算速度也大大加快，处理后的指纹图像细化完全，骨架接近纹线中心线，光滑无毛刺，方便特征提取和减少匹配的复杂度。

Improved thinning method to fingerprint image

Thinning is a very important process in Automatic Fingerprint Identification System(AFIS). But the existing thinning algorithms have many problems such as thinning not to one pixel, ridge swallowing, thinning skeleton not in ridge center and so on.Through researching and analyzing the algorithm of image post processing, an improved image template thinning algorithm was proposed based on a group of modified templates. The experimental result prove that the algorithm is completed, and the refined fingerprint skeleton is in the middle line of grain line and burr-free.Compared with the traditional refinement algorithm,the refinement result is closer to the fingerprint grain line center,so it is convenient for characteristic extracting and it reduces the matching complexity.