Claims:We Claim,
1. A system to generate a standardized iris image for resolving server sensitivity to interoperable iris patterns in an iris biometric system thereby reducing the equal error rate of iris images in the biometric system, the system comprises;
a data storage device for storing iris images collected from various databases of biometric system;
a computer system for generating a standardized iris template from the collected iris images and for normalizing the standardized iris template to form a normalized iris template; and
a storage database attached with the computer system for storing the normalized iris template thereby making the normalized iris images interpretable.

2. A method to generate a standardized iris image for resolving server sensitivity to interoperable iris patterns in an iris biometric system thereby reducing the equal error rate of iris images in the biometric system, the method comprising the steps of:
collecting iris images stored in various biometric system;
standardizing the collected iris image in a computer system attached with a storage database and thereby generating a standardized iris template; and
normalizing the template of the iris in the computer system and storing the normalized iris template in the storage database.

3. The method as claimed in claim 1, wherein the standardized iris template is generated using tree structure of wavelets filter banks.

4. A method for fabricating an artificial iris with light modulation functionality to spoof the server of the iris biometric system, the method comprising the steps of:
coating a commanding layer of hydrophobic fluorine on a Poly di-methyl siloxane substrate and photoresist the commanding layer with an iris pattern;
arranging a photomask of iris dimensions over the commanding layer in a contact printing mode and exposing to ultraviolet light, thereby changing the ultraviolet exposed region of the commanding layer of fluorine to hydrophilic;
dip coating the commanding layer with liquid crystal polymer solution and exposing to ultraviolet light, thereby generating a frill pattern of the iris guided by selective wetting inscription; and
spin coating a photochromic molecule doped with Poly di methyl siloxane substrate over the commanding layer.

5. The method as claimed in claim 4, wherein the step for generating the frill pattern of the iris is guided by selective wetting inscription.

6. The method as claimed in claim 4, wherein the photochromic molecule is an azobenzene or a spiropyran, or a phenoxyquinone or a bisthienylethene.

7. The method as claimed in claim 4, further includes a step for analysing the light modulation property of the artificial iris.

8. The method as claimed in claim 7, wherein the analysis is done by a control circuit using photodiode.
, Description:Field of the invention:
The present invention relates to a method and a system for resolving sensor sensitivity of an iris biometry towards interoperable iris patterns. More particularly the present invention relates to a method and a system to generate a standardized iris image for resolving the sensor sensitivity of iris biometry towards interoperable iris patterns.
Background of the invention
An eye is one of the most amazing biological systems, among those exist in humans. It has the capability to sense, react and regulate, thus provide the responsive media for humans to get connected with the surrounding world intellectually. The ongoing research in the field of artificial iris fabrication has emerged from the outcome of variety of requirements in ocular prosthesis and also from the technological aspects for betterment of anti-spoofing mechanism in iris biometric systems, specially to make the existing biometric (iris recognition) strong against forgery.

At the beginning considering the first aspect, the world of ophthalmology is paying considerable attention towards the ocular prosthesis for the persons suffering from visual impairment. It has been observed that the patients with permanent iris damage, suffers from excessive light exposure leading to photophobia, glare, and poor vision. In such cases the ocular prosthesis of artificial iris is useful. Most of the existing methods of artificial iris and pupil construction are capable of resembling the anatomy of iris; however, the dynamic response to light is the main function of iris which is still lacking in the artificial iris fabrication. All these requirements have caused the emergence of new challenges in fabrication of artificial iris.

The fabrication of artificial iris need to consider, i) biocompatibility of the material with the human body, ii) the structural conformation with the spoke patterns surrounding the pupil and most importantly iii) the capability of light regulation through iris i.e photo intensity modulation.

While dealing with the material selection, biocompatible flexible polymeric materials are of particular interest for fabrication of artificial iris. In general the polyethylene terephthalate (PET), Polymethymethacrylate (PMMA), polycarbonate (PC) are the most widely used polymers for artificial iris fabrication. Polydimethylsiloxane (PDMS) is also one of the well known biocompatible polymers and has advantages, such as nontoxicity, ace of fabrication, practical scalability, optical transparency, and gas (especially O2) permeability. Considering these facts the use of the PDMS for present work is intended. Another important aspect is human cornea absorb UV-C and UV-B radiation up to ~290 nm and only light above 290 nm reaches the iris and lens. The use of PDMS polymer matrix can be one of the best remedy to accomplish this demand.
However the resemblance of artificial iris with that of spoke pattern which naturally occurs in iris can be achieved using liquid crystalline polymers (LCP)

The integration of light modulation functional property in the artificial iris is prime demand. The Recent scenario of artificial iris fabrication has shown the variety types of approaches in order to inhabit the light responsive mechanism. One of the approaches could be the use of photochromic compounds for light intensity modulation, use of spiropyran dye in PMMA is reported for artificial iris fabrication. The dyes having maximum absorption at 450 nm, 570 nm and 600 nm was used in combination to regulate light intensity, thus in this case artificial iris control the light intensity in UV-visible range.

It has been observed that none of the above mentioned reports; give the detailed description about the particular region wavelengths (deep UV, UV, Visible and near IR region) passing through iris. However it is well known that natural eye allows only certain intensity of light wavelength for all particular regions.

It is important to mention here that artificial iris light modulation functionality is not only about light intensity modulation but actual successful mimicking of iris will depend on how closely it can mimic the natural light filtration functionality of an iris, which include the filtration of all the wavelengths in the region viz. deep UV, UV, visible and near IR.
Hence there is a need of a system and a method which will overcome the drawback of the present method.

Object of the invention
Object of the present invention is to provide a method and a system which can resolve sensor sensitivity of an iris biometric system towards interoperable iris patterns.

Yet another object of the present invention is to provide a method and a system which make an error resilient iris database.
One more object of the present invention is to provide a method and a system which can strengthen the iris database against a spoof attack.
Further object of the present invention is to provide a method and a system which is more reliable and more economical and easy to use.
Further one more object of the present invention is to provide a method and system which can minimize the equal error rate of the iris image in the biometric system.
Another objective of the present invention is to provide a method to fabricate an artificial iris using a photochromic compound to spoof the iris biometric system.

Summary of the invention
In accordance to the present invention, a system and a method to generate a standardized iris image for resolving server sensitivity to interoperable iris patterns in an iris biometric system is provided. The system comprises a data storage device, a computer system and a storage database. The data storage device collects and stores iris images from various databases of iris biometric system. The computer system converts the iris image to a standardized iris template and then to a normalized iris template. The normalized iris template is stored in the storage database. Also a method for fabricating an artificial iris is provided.
Brief description of drawings
The advantages and features of the present invention will become better understood with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:
Figure 1 illustrates the schematic block diagram of the system;
Figure 2 illustrates the diagram depicting the formation of iris template in the system;
Figure 3 illustrates the tree structure of wavelet filter banks;
Figure 4 illustrates the structure of sets of decimators;
Figure 5 illustrates a graphical representation of iris images with interoperability correction and without interoperability correction;
Figure 6 illustrates the method of forming iris template in accordance with the present invention; and
Figure 7 illustrates the method of fabrication of artificial iris.
Detailed description of the invention
An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.

The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

The present invention provides a method for resolving the sensor sensitivity of iris biometry towards interoperable iris patterns. The present invention also provides a method for fabricating an artificial iris using photochromic compounds. The present invention provides a method for making an error resilient iris database. The present invention can strengthen the iris database against spoof attack. The present invention is more economical and easily operable and easy to use. the present invention can minimizes the equal error rate of iris image in the biometric system.

Referring now to figure 1, a system 100 to generate a standardized iris image for resolving server sensitivity to interoperable iris patterns in an iris biometric system is illustrated. The system 100includes a data storage device 10, a computer system 20 and a storage database 30.
The data storage device 10 is for collecting and storing iris images from various databases of iris biometric system. The data storage device 10 is a portable data storage device 10. The data storage device 10 is interfaced to the computer system 20. The computer system 20 helps in standardizing an iris image and normalizing the iris image. The storage database 30 is interfaced with the computer system 20 for storing the output from the computer system 20.
After collecting the iris images from the databases of various iris biometric system, one of the iris image is selected for standardization. Standardization is done using the computer system 20. After standardization, the computer system 20 generates a standardized iris template. The standardized iris template is normalized in the computer system 20 to generate an iris normalized template. Figure 2 shows the formation of iris template in the system 100. The standardized iris templates are created using tree structure of wavelets filter banks. The typical tree structure is shown in figure 3. The uniform trees are built from the structure of sets of decimators. This structure is shown in figure 4.
The number of occurrences for each iris pattern (Nj) of each decimator nj is captured using:

Here, L=K(lcm(ni)) for positive integer values of K. The tune up of iris templates using tree structures results in consistent ni and K derivants. This in effect results into resolving issue of interoperability.
The system 100 can reduce the equal error rate of iris images in the biometric system. Figure 4 shows an interoperability correction of two iris images.
The blue curve indicates iris image without interoperability correction and the red curve shows with interoperability correction. The equal error rate (EER) of blue curve is 19.87% and that of red curve is 1.90%.
Referring to figure 5, another aspect of the present invention is illustrated. A method 200 to generate a standardized iris image for resolving server sensitivity to interoperable iris patterns in an iris biometric system is provided. For the sake of brevity the method 200 will be explained in conjunction with the system.
The method starts at step 210
At step 220, the iris images are collected and stored in a data storage device 10, the storage device 10 is then interfaced with a computer system 20.
At step 230, the iris images are converted to a standardized iris template using the computer system 20.
At step 240, the standardized iris image is normalized to get a normalized iris template, wherein the normalization is done for enhancing the iris image.
At step 250, the normalized iris image is stored in a storage database 30 interfaced with the computer system 20.
The method ends at step 260.

Now referring to figure 6, a method for fabricating an artificial iris with light modulation functionality to spoof the server of the iris biometric system is illustrated. The method is referred as numeral 300.
The method uses a photochromic compounds for fabricating artificial iris, which shows light driven molecular switching. The photochromic compound can be an azobenzene, spiropyran, phenoxyquinone and bisthienylethene will be doped in a host Poly di methyl siloxane substrate (PDMS) polymer with different combination ratios to control the intensity of the light over UV-visible range of the spectrum. While using the photochromic molecules, optimization of mixing ratio of host PDMS polymer and amount of all the photochromic molecules will be carried out; in order to get proper functionality mimicking of the natural iris. Thus the light intensity modulation over the whole deep UV, UV, visible and near IR range of light will be achieved.
The method 300 requires a PDMS substrate and a hydrophobic chlorine. As a first step, a commanding layer (CL) of the hydrophobic fluorine is coated on the PDMS substrate and subsequently with photoresist on it. Then a photomask of iris dimension is positioned over the commanding layer of the hydrophobic fluorine in contact printing mode and exposed to ultraviolet light. This changes the ultraviolet exposed region to hydrophilic which is known as selective wetting inscription. Now the commanding layer is dip coated with a liquid crystal polymer solution and again exposed to ultraviolet light thereby generating a frill pattern or spoke pattern guided by selective wetting inscription. Finally the photochromic molecule doped with the PDMS is spin coated over the commanding layer to form the artificial iris. It is obvious to a person skilled in art to use photochromic molecule of same properties.
Further the light modulation property of the artificial iris is analysed. A control circuit using photodiode is build to test and analyse the proper light modulation functionality of the fabricated artificial iris.
The present invention has an advantage of resolving sensor sensitivity of iris biometric system towards interoperable iris patterns. The present invention helps to make an error resilient iris database. The present invention strengthens the iris database from spoof attack. The present invention is reliable and easily operable and is economical. The present invention provides method for fabricating an artificial iris with low cost.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.