计算机工程 ›› 2018, Vol. 44 ›› Issue (8): 251-256.doi: 10.19678/j.issn.1000-3428.0048024

• 图形图像处理 • 上一篇    下一篇

傅里叶频域下基于曲面变换的指纹增强算法

梅园 a,b,c,张夏苗 c   

  1. 南京信息工程大学 a.江苏省网络监控中心; b.江苏省大气环境与装备技术协同创新中心; c.计算机与软件学院,南京 210044
  • 收稿日期:2017-07-19 出版日期:2018-08-15 发布日期:2018-08-15
  • 作者简介:梅园(1981—),男,副教授、博士,主研究方向为图像处理、机器学习、自动指纹识别;张夏苗,硕士研究生。
  • 基金项目:

    国家自然科学基金(2012g094);中国博士后基金(20110491413)。

Fingerprint Enhancement Algorithm Based on Surface Transformation Under Fourier Frequency Domain

MEI Yuan a,b,c,ZHANG Xiamiao  c   

  1. a.Network Monitoring Center of Jiangsu Province; b.Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology; c.School of Computer and Software,Nanjing University of Information Science and Technology,Nanjing 210044,China
  • Received:2017-07-19 Online:2018-08-15 Published:2018-08-15

摘要:

已有傅里叶频域下的指纹增强工作存在指纹非平缓区域增强效果较差、块窗口尺度不易选择的缺陷。为此,提出一种新的基于曲面变换的指纹增强算法。把曲面变换(定位曲面区域并映射到二维数组)用于傅里叶频域下,根据曲面区域的频谱图选择合适的滤波器方向。将指 纹图像划分为平缓区域与非平缓区域,只对非平缓区域执行曲面变换以提高执行效率,引入复合窗口模板来解决块窗口尺度问题。实验结果表明,相比于非曲面算法,改进方案有更好的增强效果,增强后指纹的匹配正确率可以达到99.74%,同时,运行时间比曲面Gabor算法明显 降低。

关键词: 指纹, 傅里叶变换, 曲面变换, 滤波器, 指纹增强

Abstract:

The previous works enhance fingerprint images in Fourier domain based on block.But there are some shortcomings in these works,they are not robust enough to non-smooth areas,and the size of the window is not easy to determine.A curved- regions-based fingerprint enhancement algorithm in Fourier domain is proposed to solve these problems.Curved-region transform,which finds curved region and map to 2-D array,is used in Fourier domain,and filters are designed based on the frequency images of curved regions.Fingerprint image is partitioned into smooth areas or non-smooth areas,and only construct curved regions in non-smooth areas in order to improve the execution efficiency.Composite window is introduced to resolve the choice of window size.Experimental result shows that the improved method has better enhancement effect than the algorithms based on block.The matching accuracy of enhanced fingerprints can reach 99.74%.At the same time,the running time is significantly lower than that of the surface Gabor algorithm.

Key words: fingerprint, Fourier transformation, surface transformation, filter, fingerprint enhancement

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