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.