基于临界特征点的图像匹配算法

指纹图像质量的自动评价是指纹识别系统中的关键步骤。该文从指纹识别实际应用的需要出发,提出了一种指纹图像质量的自动评价方法。该方法从指纹采集的有效区域、指纹按压的位置、图像的灰度变化、方向一致性及脊线纹理清晰程度等方面综合评价指纹图像,在指纹登录过程中对图像质量不好的情况给用户有效的提示,以便重新获得更高质量的图像;对指纹局部区域的质量等级进行标注,提高指纹特征匹配的可靠性。实验结果表明这种方法能够对不同质量的指纹图像进行有效的评价,提高了自动指纹识别系统的准确性和可靠性。

Image Matching Algorithm Based on Critical Feature Points

Automatic evaluation of fingerprint image quality is an important step in automatic fingerprint identification system.According to the requirement in real application of fingerprint identification system,an automatic quality evaluation algorithm of fingerprint images is proposed.The method integrally evaluates the quality of captured fingerprint images in several respects,such as fingerprint foreground area,pressing position of finger,gray-level variation of fingerprint image,orientation consistency and clarity degree of ridge-valley structure.The algorithm can accurately prompt the user for different kinds of bad quality fingerprint images in the process of fingerprint capture,and can also mark the region of bad quality to ensure reliability of fingerprint feature matching.The experimental results prove the method effective.