We completed some works as below:1.We achieved some pretreatment arithmetics in common use now, they can do filtering, two-valued disposing, thining to fingerprint image.

• 本文主要完成了以下工作：1．实现了多种指纹预处理算法，可以选择不同方法对指纹图像进行滤波、二值化、细化处理。