20-04-2010, 05:08 PM
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Technical Seminar
On
IRIS RECOGNITION
Presented By
NANDAN.T.MURTHY
CITY ENGINEERING COLLEGE
Biometric System
A biometric system refers to automatic
recognition of an individual based on
their physiological and behavioral
characteristics.
Physiological characteristics include
physical characteristics like
face,fingerprints,iris patterns etc.
Behavioral characteristics include
signature, speech patterns etc.
Whatâ„¢s iris?
It is the colored portion (brown or
blue) of the eye that regulates the size
of the pupil.
The coloration and structure of two
irides is genetically linked but the
details of patterns are not.
Why IRIS?
They have stable and distinctive
features for personal
identification.
They are stable with age.
Extremely data rich physical structure
about 400 identifying features.
Its inherent isolation and protection
from the external environment.
The impossibility of surgically
modifying it without unacceptable risk
to vision.
Individuality of Iris
Iris Recognition System
I. Image Acquisition
It deals with capturing of a high
quality image of the iris.
Concerns on the image acquisition rigs
:-
Obtain images with sufficient resolution
and sharpness
Good contrast in the iris pattern with
proper illumination
Well centered without unduly
constraining the operator
Artifacts eliminated as much as possible
I. Image Acquisition
ll. Iris localization
Iris localization is a process to
isolate the iris region from the rest of
the acquired image.
Iris can be approximated by two
circles, One for
iris/sclera boundary and another
for iris/pupil boundary.
How localization is done?
Normalization
Feature Encoding
Feature encoding was implemented by
convolving the normalized iris pattern
with 1D Log-Gober wavelet.
2D normalized patterns are broken up
into a number of 1D signals
Each row corresponds to a circular ring
on the iris region
The angular direction is taken rather
than the radial one, which corresponds
to columns of normalized pattern.
IV. Pattern Matching
For matching, the Hamming distance was
chosen as a metric for recognition.
The Daugman system computes the
normalized Hamming distance. The hamming
distance between iris code X and Y is
given by:
The result of this computation is then
used as the goodness of match, with
smaller values indicating better
matches.
If two patterns are derived from same
iris,the hamming distance between them
will be close to 0 due to high
correlation.
In order to account for rotational
inconsistencies, one template is shifted
left and right bit-wise and a number of
Hamming distance values are calculated
from successive shifts.
Advantages of the Iris forIdentification
Highly protected, internal organ of the
eye.
Patterns apparently stable throughout
life.
Iris patterns possess a high degree of
randomness.
extremely data-rich physical structure.
Image analysis and encoding time: 1
second.
Search speed: 100,000 Iris Codes per
second.
Disadvantages of the Iris for Identification
Small target (1 cm) to acquire from a
distance (1 m)
Characteristic natural movement of an
eyeball while text is read.
Obscured by eyelashes, lenses,
reflections
Deforms non-elastically as pupil changes
size
Illumination should not be visible or
bright
Applications
Current uses:-
airports
government agencies
research laboratories
In prisons
Future uses:-
healthcare industry
Emigration services
sales transaction
Conclusion
Based on the study we can conclude
that iris recognition is one of the
reliable and accurate biometric
technology.