Study On Fingerprint Image Processing Of Fingerprint Identification Technique

Along with development of society, traditional security systems which based mainly on token or password become fragile and cannot meet the demand of modern security system. Which makes people research for new security system that is safer and more difficult to fabricate than the traditional security system. Fingerprint recognition technique that is safer and has more feasibility was appeared under this circumstance. Fingerprint recognition technique can use our body's physical characters to make itself becoming a safer security system.A fingerprint is the pattern of ridges and valleys on the surface of a fingertip. Modern statistics has proved that fingerprint is unique and steady, that means, one's fingerprint is different from all others and will not change all his life. As one kind of biometric recognition technique, fingerprint recognition technique is widely used in forensic, police and other security system. Recently, as the development of micro -computer technique and embed developing system technique, automated fingerprint identification system (AFIS) has made a great progress. This article is meanly stress on the fingerprint image processing technique that is one of the key techniques of automated fingerprint identification system.This article analyses the characteristic of fingerprint image and brings forward some reasonable supposes which related to the fingerprint image after I collected and analyzed many articles of others that is related to the fingerprint image processing and has published in the resent years. Based on these characteristic and supposes, I developed a set of fingerprint image processing arithmetic that are adapt to the fingerprint image gathered by capacitive solid-state device. These include several steps. They are refining the effective area, analyzing quality, segmentation, filtering noise, thinning, refining the minutiae, analyzing reliability and matching of fingerprint image. This article uses the direction-based arithmetic to segment the fingerprint image. It's merits and demerits are discussed in this article. Arithmetic that is based on the sum of fingerprint's grey level variety is used to refining the effective area of fingerprint image. A seed-filling arithmetic is used to filtering the hole-like noise of the fingerprint image. An effective method to segment the grey level finger- print image is to use these three methods at thesame time. This article states the thinning arithmetic in detail and gives a pseudo language program of the seed filling arithmetic. Besides, this article makes an attempt to refine the skeleton of the fingerprint valleys from the grey level fingerprint image. In the chapter of fingerprint's post processing, this article gives the method of analyzing reliability of minutiae and high-speed fingerprint matching arithmetic which demerit is that the False Reject Rate is a little high. But it works effectively in actual.In the end of this article, an example using fingerprint processing and the problems occurred in actual are given. Besides, problems that are not fully solved are mentioned...