低质量指纹图像方向场提取方法

指纹方向场提取是自动指纹识别系统中的重要环节，是解决自动指纹识别中的某些关键技术的基础。提出了一种通过线性投影分析和在sin域中用加权低阶二维勒让德多项式拟合提取指纹方向场的方法；解决了大噪声低质量指纹图像方向场难以准确提取的问题；在FVC 2000指纹数据库中的大量实验表明，与已有基于梯度的指纹方向场估计算法相比，该方法有更好的提取精度和鲁棒性，对于大噪声的低质量指纹图像能给出很好的方向场估计。

The orientation field extraction method of low quality fingerprint

Estimation of the fingerprint orientation field plays an important role in automatic fingerprint recognition system. In this paper, a new algorithm for computing the fingerprint orientation field is proposed. The basic idea behind the algorithm is to estimate the local region orientation use linear projection analysis and weighted lower order two-dimensional Legendre polynomials in the sine domain. This method solves the problem that is difficult to accurately extract low quality fingerprint image orientation fields. Experiments on the database of FVC 2000 show that, compared with the previously proposed gradient-based methods, the proposed method is more accurate and more robust against noise, and is able to better estimate fingerprint orientation field of low quality fingerprint image with large noisy areas.