The need for biometrics
As per wikipedia,
“Biometrics consists of methods for uniquely recognizing humans
based upon one or more intrinsic physical or behavioral traits”
The need for biometrics
o -> Rapid development in technology
o -> Globalization
Anatomy of the Human Eye
• Eye = Camera
• Cornea bends, refracts,
and focuses light.
• Retina = Film for image
projection (converts image
into electrical signals).
• Optical nerve transmits
signals to the brain.
What is Iris?
The coloured ring around the pupil of the eye is called the iris
,like a snowflake.
Controls light levels inside the eye.
Tiny muscles that dilate and constrict the pupil size.
Divides the front of the eye from the back of the eye.
Color comes from melanin.
brown or black in colour
Individuality of Iris
Left and right eye irises have distinctive pattern.
Characteristics of Iris
Has highly distinguishing texture.
Right eye differs from left eye.
Twins have different iris texture.
Iris pattern remains unchanged after the age of two and does not
degrade overtime or with the environment.
Iris patterns are extremely complex than other biometric patterns.
What Is It?
Going the layman way the biometric identification of the iris is called as
But as per WIKIPEDIA,
“Iris recognition is a method of biometric authentication that uses
pattern-recognition techniques based on high-resolution images of the
irides of an individual's eyes.”
400 identifying features
The iris is a living password
Artificial duplication is virtually impossible
Probability of matching of two irises is 1:1078
Its inherent isolation and protection from
the external environment.
• Idea was proposed by ophthalmologist Frank Burch
• Appeared in the Bond Films
• Aram Safir & leonard Flom patented the idea and asked John
Dougman to create actual algorithms for that. John Dougman created
this algorithm and patented that in the same year..
• Licensee Sensar deployed special cameras in ATMs of NCR corps and
• “Panasonic Authenticam‖ was ready for use in public places like airports
Iris on the Move: Acquisition of
To acquire images with sufficient resolution and sharpness to support recognition.
A. Optics and Camera:
Human heads are on the order of 15 cm wide.
In case of a portal, we needed a capture volume width on the order of 20–30 cm.
More than 200 pixels or more across the iris- Good quality.
Of 150–200 pixels across the iris – Acceptable quality
Of 100–150 pixels to be of- Marginal quality.
The shutter is only open during the strobe to reduce the effect of
C. Coarse Segmentation:
Daugman algorithm expects 640 x 480 images.
Both the inner boundary and the outer boundary of a typical iris can be taken
But the two circles are usually not co-centric.
The inner boundary between the pupil and the iris is detected.
The outer boundary of the iris is more difficult to detect because of the low
contrast between the two sides of the boundary.
The outer boundary is detected by maximizing changes of the perimeternormalized along the circle.
The size of the pupil may change due to the variation of the illumination and the
associated elastic deformations in the iris texture may interfere with the results of
Since both the inner and outer boundaries of the iris have been detected, it is easy to
map the iris ring to a rectangular block of texture of a fixed size.
How closely the produced code matches the encoded features stored in the
One technique for comparing two IrisCodes is to use the Hamming distance,
which is the number of corresponding bits that differ between the two IrisCodes.
John Daugman (1994)
• Pupil detection: circular edge detector
• Segmenting sclera
max G (r )
r , x0 , y 0
r r , x0 , y 0
I ( x, y )
Each pixel (x,y) is mapped into
polar pair (r, ). θ
Circular band is divided into 8
Sub-bands of equal thickness for a
given angle θ .
Measure of Performance
• Off-line and on-line modes of operation.
Hamming distance: standard measure for comparison of binary strings.
x and y are two IrisCodes
is the notation for exclusive OR (XOR)
Counts bits that disagree.
• Two IrisCodes from the same eye
form genuine pair => genuine Hamming
• Two IrisCodes from two different eyes
form imposter pair => imposter Hamming
• Bits in IrisCodes are correlated (both
for genuine pair and for imposter pair).
• The correlation between IrisCodes
from the same eye is stronger.
Iris Recognition System
· Highly protected, internal organ of the eye
· Externally visible; patterns imaged from a distance
· Iris patterns possess a high degree of randomness
.Uniqueness: set by combinatorial complexity
· Changing pupil size confirms natural physiology
· Limited genetic penetrance of iris patterns
· Patterns apparently stable throughout life.
A key advantage of iris recognition is its stability, or
longevity, as, barring trauma, a single enrollment can last a lifetime.
· Small target (1 cm) to acquire from a distance (1m)
· Located behind a curved, wet, reflecting surface
· Obscured by eyelashes, lenses, reflections
· Partially occluded by eyelids, often drooping
· Deforms non-elastically as pupil changes size
· Illumination should not be visible or bright.
.Fugitive track record
.Computer login: The iris as a living password.
· National Border Controls: The iris as a living password.
· Ticket less air travel.
· Premises access control (home, office, laboratory etc.).
· Driving licenses and other personal certificates.
· Entitlements and benefits authentication.
· Forensics, birth certificates, tracking missing or wanted person
· Credit-card authentication.
· Automobile ignition and unlocking; anti-theft devices.
· Anti-terrorism (e.g.:— suspect Screening at airports)
· Secure financial transaction (e-commerce, banking).
· Internet security, control of access to privileged information.
The remarkable story of Sharbat
Gula, first photographed in 1984
aged 12 in a refugee camp in
Pakistan by National Geographic
McCurry, and traced 18 years
later to a remote part of
Afghanistan where she was
again photographed by McCurry.
So the NG turned to the inventor
of automatic iris recognition,
John Daugman at the University
The numbers Daugman got left
no question in his mind that the
eyes of the young Afghan
refugee and the eyes of the adult
Sharbat Gula belong to the
Iris is seen as the saviour of the UID project in India.
A U.S. Marine Corps Sergeant uses an iris scanner to positively identify a member of the
Baghdadi city council prior to a meeting with local tribal leaders, sheiks, community leaders and
U.S. service members.
Shape of letters,
Order, pen pressure
Outline, shape &
distribution of eyes, nose
size, length, &
Iris recognition has proven to be a very useful and versatile
It is a quick and accurate way of identifying an individual with no
chance for human error.
Iris recognition is widely used in the transportation industry and
can have many applications in other fields where security is
Iris recognition will prove to be a widely used security measure
in the future.
Daugman J (1999) "Biometric decision landscapes."
Technical Report No TR482, University of Cambridge
International Journal of Computer Technology and
Electronics Engineering (IJCTEE) Volume 2, Issue