基于频域的指纹图像增强算法

介绍一种基于频域的指纹图像增强算法，提出了一种新的纹线方向场估计方法，并根据纹线频谱分布特点，将求取方向场仅限定在了一个较小的圆环区域内进行。提出了基于纹线频谱能量分布的指纹图像滤波算法，它通过计算块频谱图中纹线频谱能量分布范围的变化自适应地改变角度滤波器通带范围。实验对比结果表明，经该算法增强后的图像脊谷信息清晰，具有较好的纹线增强效果。

A Requency Domain-Based Algorithm for Fingerprint Image Enhancement

In this paper,introduces an approach for fingerprint enhancement based on frequency domain analysis.Firstly,propose a new way to estimate the direction field of fingerprint image.And according to the distribution of the texture frequency,the acquirement of the direction field is limited in a relatively small cycle region.Secondly,an algorithm of fingerprint image enhancement based on analysis of distribution of texture spectrum energy is introduced,the band pass range of band-pass filter changes automatically by calculating the changes of the texture spectrum distribution in the block spectrum image.Experimentally compare the proposed approach to other filtering approaches in literature and show that the methods producing a better enhancement effect.