Study On Restoration Method Of The Fuzzy Iris Image

With the development of computer technology and applications,biological characteristics recognition technology is becoming more and more mature,and the application domain is expanding unceasingly,which is from national security to personal computer passwords and so no,and it has certainly applied in the different domain and the different level.Meanwhile the methods of biological characteristics those people have gained are more and more,and the types of biometric characteristics we have gained are increasing.Now the biological characteristics people used commonly are:iris recognition,face recognition,fingerprint recognition, palm-print recognition,writing recognition,Voice recognition,etc.For a particular person,no matter what the method of biological characteristics recognition is,and what the types of biological characteristics we gained,his biological characteristics which is the human body itself inherent.Will affect besides few factors,once formed it will not change.Thus,the biological recognition technology which is base on the human body itself inherent is becoming to spring up.And compared with other biological characteristics,iris has more good natures, primary because of the high degree of iris's repeatability,this method of status recognition is more practical and more reliable.As an important characteristic of identity recognition,iris also has a series of good nature such as acquisition, non-infringing,etc.And the biological characteristics recognition technology of non-infringing namely non-contact type is the inevitable trend of physical characteristics studies and applies development.Compare with other non-contact type biological technology,the iris has a higher accuracy.When the iris recognition technology combination of the corresponding algorithm,we can achieve a very high accuracy.Even if the iris information of all world person's inputs to a database,the probability of appears recognizes false and resists real is a very small probability.The veracity of iris recognition is the highest in all those of biological recognition,so iris recognition is one of the most promising biological recognition technology,the iris identity recognition technology gradually drawn the attention of the academic and the business community.In fact there are many kinds of reasons that cause the iris image fuzzy.For example:as in the process of imaging,iris is affected by collecting equipment,light changes,defocus,and other factors,but defocus is the common.Defocus is an unexpected factor for iris image fuzzy;therefore under the overwhelming majority situation,defocus is unpredictable.This is because iris collection is the most important step in iris recognition.But owing to the variable focus sampling equipment is very costly,so the great mass of the image sampling equipment don't have the function which can adjust the focus,the image that we gained is often defocusing.In fact,in the majority imaging processes there is a defocus either light or the heavy,this created that the iris image which we obtained is fuzzy.Now we use the iris recognition system which is proposed by Daugman in 1993 has already mature greatly. But the precondition is that recognition has to process when the iris image is clear,the fuzzy image brings many difficulties to the iris recognition.Something else,there is noise during the image sampling,which effects the quantity of image.Because the information of noise is uncertain,denoising is also a significant problem for iris image restoration.So how to get the clear image is become very important.Therefore,the study on fuzzy iris image restoration has the practical significance for enhances the fidelity with the original image.In this paper,the title is the study on restoration method of fuzzy iris image, researches aimed at improving the quality of iris images,carries on the defocus fuzzy iris restoration with computer,and further improve the precision of fuzzy iris image restoration.Based on the characteristics and requirements of the project,this paper is mainly aimed at study on restoration method of fuzzy iris image which is acquired by changeless focus camera.The key of iris image restoration lies in the setting of degradation model of fuzzy image,the problem of denoising and the decision of the parameter of degradation model.And the traditional method of the defocus fuzzy iris image restoration has been improved in this paper,the main work in this paper as follows:This paper firstly gives a detailed explanation on the role of human biological certification in real life,the mathematical model of image restoration as well as some classical methods of the restoration.And it pointed out the study focus and difficulty in current days in the-area of iris image restoration research.This paper also expatiates the process of the iris restoration realization details.Finally using the computer to carries on the defocus fuzzy iris restoration.This paper study aimed at the defocus fuzzy iris image.Combine with the author's work in the iris recognition research,the paper does a deep study on iris image acquisition,autofocusing processing of fuzzy iris based on power spectrum, and the algorithm that iris image restoration to the image recovery technology.The parameter of degradation model in defocusing iris image can be abstracted as a disc function,its corresponding radii of the disc is the only the parameter of degradation model(the blur radii).The writer gives a detailed illustration about the getting of this parameter.We used the finite ridge let transform for iris image denoising.It can reduce the adverse effect of the noise to the defocus fuzzy iris image restoration to a certain extent.This paper also improves the iterative method of iris fuzzy iterative image restoration algorithm,and enhances the computing speed,and using the computer to carries on the defocus fuzzy iris restoration.The result of the fuzzy iris restoration shows that the methods in the paper can overcome the impact of defocus fuzzy iris image and other reasons to a certain exten.As the superior characteristics of iris,the gradually improving of iris acquisition device and the continuous development of the methods of fuzzy iris image restoration, iris recognition technology will become an excellence model of the biometric identification technology.