指纹图像细化是指纹识别算法中的重要环节，对特征提取起到关键作用。为了快速和高质量地对指纹图像进行细化，对快速细化算法和改进OPTA细化算法不足产生的内在原因进行分析，提出一种新的复合式指纹图像细化算法，该算法设计一套预处理模板，避免了快速细化算法形成的毛刺，并对改进OPTA算法进行了优化。大量实验结果表明，该算法不但具有以往算法的优点，有较好的细化速度，而且细化质量有显著地提高，细化后的图像光滑几乎无毛刺。

Fingerprint image thinning is an essential step in the fingerprint recognition system, which plays a key role in the feature extraction. In order to thin the fingerprint image efficiently, we analyze the underlying causes of the disadvantages of the existing fast parallel thinning algorithm and the improved OPTA thinning algorithm, and then present a new composite fingerprint image thinning algorithm is presented in this paper. A set of preprocessing templates are designed to smooth images after fast thinning. In addition, the improved OPTA algorithm is optimized for speed. A large number of experimental results show that, the presented algorithm has high thinning speed, and can obtain good thinning quality.