摘要
尽管指纹图像具有局部方向一致性,但在一些局部区域,尤其是包含指纹奇异点的区域点方向变化仍然较大。鉴于此在求出指纹各个像素的点方向以后对指纹图像进行分块,引入了方向信息可靠块和方向信息不可靠块的概念。对方向信息可靠块提出一种用方向信息分割指纹图像的方法。对方向信息不可靠块,采用两种方法区分出指纹块和背景块:一是利用该块的均值、方差;二是利用邻域信息。在此基础上对不可靠块中的指纹块采用加权模糊C-均值聚类的方法对其进行二值化。实验表明:用本文提出的方法对指纹图像进行二值化处理后得到的二值图像脊线光滑无孔洞、对断线起到了一定的连接作用,而且对于方向变化较大的分块避免了二值化后纹线的偏移。
Although fingerprint image has direction consistency in local area, the point directions change largely in some regions especially in the areas including the singular points. Based on this fact, the concepts of directional reliable block and directional unreliable block are introduced when the point direction image is obtained and the fingerprint image is divided into blocks. For the segmentation of directional reliable blocks, a method that using directional information is proposed. For the segmentation of directional unreliable blocks, two methods are used to separate the image blocks and the background regions： one is using the mean value and variance; another is using the neighborhood information. And then, image blocks in the directional unreliable regions are segmented using weighted fuzzy C-means clustering algorithm. Experimental results show that using the proposed binary method, binary image is obtained with the merits such as ridges are smooth without holes, the break ridges are connected in some degree. In addition, ridge deviations after binarization are prevented for the blocks with largely change on directions.
出处
《计算机工程与设计》
CSCD
北大核心
2008年第23期6069-6072,共4页
Computer Engineering and Design
基金
国家自然科学基金项目(60572133)。
关键词
指纹图像
二值化
方向
加权模糊C-均值聚类
fingerprint image
binarization
direction
weighted fuzzy C-means clustering
