Iris Scanner

Ravi P. Agrahari (Science & Technology)

• Iris cameras perform recognition detection of a person’s identity by mathematical analysis of the random patterns that are visible within the iris of an eye from some distance.  It combines computer vision, pattern recognition, statistical inference and optics.

• Of all the biometric devices and scanners available today, it is generally conceded that iris recognition is the most accurate.  The automated method of iris recognition is relatively young, existing in patent since only 1994.

• The iris is the coloured ring around the pupil of every human being and like a snowflake, no two are alike.  Each are unique in their own way, exhibiting a distinctive pattern that forms randomly in utero,  n a process called chaotic morphogenesis.  The iris is a muscle that regulates the size of the pupil, controlling the amount of light that enters the eye.

• Iris recognition is rarely impeded by glasses or contact lenses and can be scanned from 10cm to a few meters away.  The iris remains stable over time as long as there are no injuries and a single enrolment scan can last a lifetime.

• The iris is the colorful part of the eye between the white sclera and the pupil.

• Iris is the only internal organ of the human body that is normally externally visible.

The iris identification program may be divided into four main functional blocks:

1.Image Acquisition.

2.Preprocessing.

3.Image Analysis.

4.Image Recognition.

• The acquired image always not only “useful” parts (IRIS), but also some “irrelevant” parts e.g. eyelid, pupil

• So the preprocessing is composed of two steps:

1.Iris Localization

2. Edge Detection

• In this stage, we should determine iris part of the image by localizing the position of the image derived from inside the limbus (outer boundary) and outside the pupil (inner boundary), and finally convert the iris part into a suitable representation.

• It is used to find complex object boundaries by marking potential edge point corresponding to places in an image where rapid change in brightness occurs.

• In other words, edge is defined by the discontinuity in gray values. An edge separates two distinct objects.

• The features of the iris are then analyzed and digitized into a 512 byte (4096 bits) Iris Code record.

• In this iris code half of the describes the features and another half of the describes the control the comparison process.

• Iris code record is stored in the database for future comparison

• During a recognition attempt, when an iris is presented at a recognition point, the same process is repeated ; however the resulting Iris Code record is not stored but is compared to every file in the database.

1. A person stands in front of the iris identification system, between one and three feet away, while a wide angle camera calculates the position of their eye.

2. A second camera zooms in on the eye and takes a black and white image.

3. Once the iris is in focus, it overlays a circular grid on the image of the iris and identifies the light and dark areas, like an “eye print”.

4. To prevent a fake eye from being used to fool system, these devices may very the light shone into the eye and watch for pupil dilation.

1.Highly Protected Internal Organ Of The Eye.

2.Externally Visible Patterns Imaged From A Distance.

3.Pattern Apparently Stable Throughout The Life.

4.Image Analysis And Encoding Time: 1 Seconds.

5.Search Speed: 1,00,000 Iris Code Per Second.

1. Computer login: the iris as a living password.

2. National border controls: the iris as a living passport.3. Driving licenses and personal certificates.

4. Internet security.

5. Premises access control (Home, Office, Laboratory).

6. Anti-terrorism (e.g. security screening at airports)

7. Financial Transactions (electronic commerce and banking).

8. Secure accesses to bank cash machine accounts.