Abstract: The importance of orientation information has been determined by the fingerprint texture characteristic in automatic digital fingerprint identification. The orientation information has been used in image enhancement, binarization, segmentation, pattern classification, image compression etc. The orientation image is a method for describing orientation information. The accuracy of orientation image determines the performance of the algorithm in automatic digital fingerprint identification. Based on binarized image, we proposed a new method for extracting fingerprint orientation image. The method is not sensitive to background noise and can represent the texture orientation of fingerprint pattern area accurately. Experiments show the robustness of the method, which can be used as post-processing after binnariztion.

Key words: fingerprint, binarization image, orientation image

摘要： 在指纹自动识别过程中，指纹的纹理特点决定了方向信息的重要性。图像的增强、二值化、分割、模式分类以及压缩等许多地方，都用到了方向信息。方向图是方向信息的表示方法，方向图的准确性决定了自动识别过程中各种算法的效果。本文在二值化处理的基础上，提出了一种不受背景干扰的指纹图像方向图算法，能够准确地反映了指纹模式区的纹理方向。实验证实我们的算法具有良好的鲁棒性，可用于二值化的后期处理。

关键词: 指纹, 二值图像, 方向图