The Design Of DSP-Based Iris Access System

In recent years, as a noncontact type identity recognition method,thebiological recognition technology (or biometrics)is valued by people more andmore. The biological recognition technology is a kind of new type patternrecognition method that takes modern biotechnology as foundation, takes the latestinformation technology as means, and integrate the biotechnology and informationtechnology.It is the technology that identifies an identity according to the humanbody physiology characteristic and behavior characteristic. The biologicalcharacteristic is unique and comparatively stabile, and it is not easy to forge andcounterfeit it, so it is of safe credible, accurate specialties to identify an identitywith the biological recognition technology. In addition, by means of the moderncomputer technology, the biological recognition product can comparative easily tocomplete functions, such as safety authentication, supervision&control andmanagement...etc. The breakthrough of biological recognition technology can bringthe important development of the safety authentication, supervision&control,management and pattern recognition theories and so on, and will produce theimportant social effect and economic benefit.The modern biological recognition technology includes fingerprint, iris, retina,face type, hand type, ear type, skeleton structure, voice, handwriting etc. The irisrecognition has the specialties such as obtaining conveniently, obviouscharacteristic and unique feature. Additional, iris recognition has the advantage ofhigh accuracy, long-term stability, difficult in falsification etc., as a result it is onekind of biological recognition technology with developable foreground accepted byeveryone, which has the important theoretical, social and economic meaning.According to the geometry and physiology characteristic of iris, this paperdescribed the realization process of iris recognition system, mainly including theacquisition of iris image,the image quality evaluation,edge locating,thestandardization,the characteristic extrating,the pattern matching and so on. Thispaper introduces how to acquire iris image by using the iris quality evaluationmethod based on the vision characteristic, which can complete the acquisitionbetter, and the acquisition quality can meet the need of the image processingcompletely.The captured images are of high quality, clear veins and easy location.The iris image also includes the other non-veins part except the veins part.In orderto keep the precision and accuracy of recognition, the edge of iris should belocated. The current positon locating algorithmic method usually has weaknesssuch as spending more time in processing. We locate the inner edge of iris byintegrating the rough and the precise method together, which can ensure theaccuracy of locating, and then improve the locating efficiency. At the same time welocate the outer edge with nonlocating method, obtaining better locating result. Theprocess of iris veins standardization is to select virtual circle on fixed layer in validregion of iris, then carry on coordinates transform and image enhancement.The wavelet transform is partial transform in time and frequency domain,which can extract information from the signal effectively.With the operation ofstretch-compressing and translation it can anatomize the function or the signal onmulti-scale. The wavelet transform can solve many difficult problems that theFourier transform can't solve, and it is known as"mathematics microscope".Therefore, we extract the iris characteristic by wavelet transform withzero-crossing method, obtaining better experiment result.In the stage of irischaracteristic match, we put forward matching verdict evaluation function:Energy-crunode-factor-dissimilitude function. Compared with current algorithmmethod used in the experiment, the system proved to have the robustness andaccuracy.This paper discusses the realization of DSP embedding based on the irisrecognition technology,and introduces the principle and design of the mainfunction module and the structure design of the system of iris access system basedon DSP(TMS320 DM642). The identity recognition project of the iris accesssystem is to capture the user's iris image(moreover,can obtain password,identitycard information and so on in the meantime), then to process the iris veinsinformation with special algorithm by using the DSP system. The processingprocedure includes quality evaluation, position locating and the iris veins regionconfirmation, the standardization processing, the extraction of the iris characteristicinformation, the establishment of a characteristic information template database,recognition and match of iris etc. In addition, this paper introduces some relatedconcepts of the DSP and the software, hardware system design of the DSP system,including the general design of the DSP system, the software and hardware designof SCM, the software process of iris capturing system etc. Parts of software flowcharts and the electric circuit principle diagram are also given. The simulation andemulation result indicates that the iris access system can work effectively and thehardware and software design is exact. The iris access system can also expandfurther function, for example, realizing the long range real-time supervision andcontrol, dynamic management and alarm processing to each iris recognition systemon net by networks which uses the network function of the DSP system, then theaccess control integrative system is constituted, and the request of safety,credibility and management are fulfilled etc. The access system integrates the irisrecognition technology, DSP, SCM with embedding technology as a whole, andadopts the advanced opening system structure. It is convenient for it to interlink themanagement system and other equipments and carry out the high integration of theuser system, so it has laid a foundation for the research on practical transformationof iris identity recognition system and has a good market prospect andindustrialization foreground.