Study Of The Check On Work Attendance System Based On Fingerprint

The fingerprint is the pattern of ridges and valleys on the surface of a fingertip. Modernanatomy and statistics have proved that each individual has unique fingerprints andfingerprint down't change all the life time, i. e. fingerprint is steady and exclusive. Thefingerprint identification is one of the most important biological technologies that include theknowledge of biology, sensoring-technology, computer science, imageprocessing, patternrecognition and computing method. The application prospect of living fingerprintidentification technology is extensive and the system of fingerprintattendance checking is anexample that adopts this technology.Based on plenty of papers and technical reports on fingerprint matching andclassification and some works on the theories on AFIS, this dissertation provides a set ofmeasurement dealing with fingerprint matching and classification captured by solid statesensors. Through experiments, this measure is proved rational and practical. The main pointsare as follows:The research of fingerprint's collecting system. The system adopted LPC2210 processoras a fingerprint processing chip, and adopted a silicon crystal sensor as fingerprint collection,CPLD as global logic control, and realize the transmission between LPC2210 and PC throughRS-232. Each part works in phase, constituting an integrity of hardware system.The research of fingerprint image's pre-processing. Its purpose is removing noise offingerprint image and improving fingerprint definition of fingerprint image, getting thestructure of image to a one gels width image, which will be beneficial to the follow featureextraction.The research of fingerprint image's minutaes extraction and matching. Minutiaesextracting mainly got fingerprint minutaes and position. Firstly, this dissertation uses8-neighborhood cross-calculation algorithm to extract all minutiaes from thepre-processed image, and we validate these minutiaes and eliminate pseudo ones throughridge tracking method. Fingerprint image matching is judging whether these two fingerprintimages are captured from the same finger. We have developed an feature point-matchingalgorithm. The matching of point is transformed into matching of vectors, which are composed ot two teature points.We also analyses and designs a system of fingerprint attendance checking. The successfulapplication of the system develops the more vast market of fingerprint identification., and,further leads the technology of fingerprint identification to the public and the industry fields.