指纹图像分割主要是去除非脊线区域、不可恢复的脊线区域和残留脊线区域，提高特征提取的准确率和减少图像处理的时间。一般说来，残留脊线具有清晰的脊线结构，单单采用基于指纹图像的特征参数很难将其有效分割。本文提出了两级分割的方法，首先通过面积参数去除分离的残留脊线区域；然后在二级分割中利用形状参数将粘连的残留脊线区域分割掉。实验结果表明，基于本文方法的细节点检测的准确率更高。

The fingerprint segmentation is aimed to exclude non-ridge regions and unrecoverable ridge regions and remaining ridges as background. This could improve the fingerprint recognition accuracy and image processing speed. In general, remaining ridges are of clear structure. Which makes it difficult to identify remaining ridges from the interested regions merely by characteristic parameters of fingerprint image. The paper proposes two steps for fingerprint segmentation aiming at removing remaining ridges from background. If the remaining and the real ridge regions are separate to each other, the area parameter is used to remove remaining ridges in the first step, In the case of conglutination, the shape features of the fingerprint image are aiming to find the optimal segmentation point in the second step. The experimental results show that the proposed method leads to adequate accuracy of minutiae detection.