非接触成像手指节纹检测算法

Extraction Method for Non-contact Finger Phalangeal Prints

指节纹因具有唯一性而成为身份认证的方法之一,现有的文献主要基于小波多分辨率分析原理提取指节纹分布信息,而本文给出了一种针对指节纹间相对位置关系进行检测的方法:首先对自建图库中大拇指向外张开、四指闭合的手掌图像,利用Step边缘检测的预处理方法定位出关键的指尖、指根点,然后将整幅手掌图像旋转至水平位置,以便于比较指节纹的相对位置分布关系,最后针对除大拇指之外的四个手指,利用Roof边缘检测的方法确定指节纹特征点.为了验证本文的方法,利用自建小型图库进行测试,结果表明正确检测率可达98.035%,验证了该方法的可行性和有效性.

Finger phalangeal prints become one of the authentication methods due to its uniqueness. Existing literatures are mainly based on the principle of wavelet multi-resolution analysis to extract the finger phalangeal prints distribution information. But the paper presents a detection method for the relationship between the relative positions of finger phalangeal prints. For self-built gallery of thumb outwardly open, four fingers closed hand images, the first step is to find out the fingertips and finger valley points by using the Step edge detection pretreatment methods. Then the whole image is rotated to a horizontal position in order to compare the relative positions of finger phalangeal prints. Finally, we can find out the horizontal coordinate position of finger phalangeal prints in four fingers except the thumb by using the Roof edge detection method. In order to verify the proposed method, the use of self-built small natural gallery display test results showed that the extraction rate is up to 98.035%, indicating that the method is feasible and effective.