The Fingerprint Image Binarization And Detailed Study

Fingerprint identification is a method to identify a person by computer based on his inherent fingerprint characteristics. Traditional high-performance automatic fingerprint identification systems are usually realized on the PC-based platforms; however, most of fingerprint entrance control systems used in many places nowadays are based on embedding platform, and therefore have greater demand for system's real-time ability and reliability.In the fingerprint entrance control system, the preprocessing of fingerprint images is the foundation of the whole system whose core is binarization and thinning. This paper mainly focuses on the algorithms of binarization and thinning, while in-depth research is carried out into the algorithms of directional image which will be used in the process of binarization and thinning. By summarizing and digesting the researching findings by scholars from both home and abroad, this paper realized many kinds of directional image, binarization and thinning algorithms by programming. At the same time, in the paper some algorithms are improved in some aspects so as to reduce the calculating time and to obtain a better quality of operation.Through experiment, the paper compares existing algorithms in the respect of calculation time and processing quality, to come up with a series of algorithms that feature little processing time and better outcome to serve as the basis for the recognition system. These algorithms include the consecutive distributing directional image algorithm, the binarization algorithm based on the slice method after directional filtering, the quick thinning algorithm based on the improved OPTA method. The results of experiment show that these algorithms mentioned above could not only accomplish individual task but also work together very well to offer good processing quality at a high speed, which have effectively solved the problem of fingerprint image's preprocessing.In the last part of the thesis, the major findings of the study are summarized and implications and limitations are pointed out to give the directions of future work.