Title: PERSONAL IDENTIFICATION
1PERSONAL IDENTIFICATION BASED ON IRIS PATTERN
By Roll No 10224002 M.Tech (Computer Tech.) NIT
Under the guidance of Assistant professor Dept.
of Electrical Engineering NIT
2Personal Identification Based On Iris Pattern
- CONTENTS
- 1.INTRODUCTION OF IRIS RECOGNITION
- What is Iris Recognition
- Human Iris
- Operating Principle
- Advantages
- Disadvantages
- History
- 2. STATE OF THE ART
3Contents (Cntd.)
- 3. TECHNICAL ISSUES
- Image Acquisition
- Segmentation
- Normalization
- Feature Encoding And Matching
- Iris Image Database
- 4 PERFORMANCE METRICS FOR IRIS RECOGNITION
- 5. APPLICATIONS OF IRIS RECOGNITION
- 6. REFERENCES
41. INTRODUCTION OF IRIS RECOGNITION
- 1.1 What Is Iris Recognition
- Iris recognition is a method of biometric authenti
cation that uses pattern-recognition techniques
based on high-resolution images of the iris of an
individual's eyes. - A Iris recognition system provides Personal
identification of an individual based on a unique
feature or characteristic possessed by the human
Iris. - The physiological complexity of the organ results
in the random patterns in iris, which are
statistically unique and suitable for biometric
measurements.
5INTRODUCTION OF IRIS RECOGNITION(Cntd.)
- 1.2 Human Iris
- The iris is a thin circular diaphragm, which lies
between the cornea and the lens of the human eye.
front-on view of the iris is shown in Figure 1.1.
-
- Figure 1.1 A front-on view of the human eye.
61.2 Human Iris(cntd.)
- The iris is perforated close to its centre by a
circular aperture known as the pupil. - The function of the iris is to control the amount
of light entering through the pupil, and this is
done by the sphincter and the dilator muscles,
which adjust the size of the pupil. The average
diameter of the iris is 12 mm, and the pupil size
can vary from 10 to 80 of the iris diameter . - The iris consists of a number of layers, the
lowest is the epithelium layer, which contains
dense pigmentation cells. The stromal layer lies
above the epithelium layer, and contains blood
vessels, pigment cells and the two iris muscles.
The density of stromal pigmentation determines
the colour of the iris.
71.2 Human Iris(cntd.)
- Formation of the iris begins during the third
month of embryonic life 3. The unique pattern
on the surface of the iris is formed
during the first year of life, and
pigmentation of the stroma takes place for the
first few years. Formation of the unique patterns
of the iris is random and not related to any
genetic factors 4. - The only characteristic that is dependent on
genetics is the pigmentation of the iris, which
determines its colour. Due to the epigenetic
nature of iris patterns, the two eyes of an
individual contain completely independent iris
patterns, and identical twins possess
uncorrelated iris patterns3. -
8INTRODUCTION OF IRIS RECOGNITION(Cntd.)
- 1.3 Operating Principle
- An iris-recognition algorithm first has to
identify the approximately concentric circular
outer boundaries of the iris and the pupil in a
photo of an eye. - The set of pixels covering only the iris is then
transformed into a bit pattern that preserves the
information that is essential for a statistically
meaningful comparison between two iris images. - To authenticate via identification or
verification, a template created by imaging the
iris is compared to a stored value template in a
database. - If the Hamming Distance is below the decision
threshold, a positive identification has
effectively been made(HDlt0.32).
91.3 Operating Principle(Cntd.)
- A practical problem of iris recognition is that
the iris is usually partially covered by eyelids
and eyelashes. In order to reduce the
false-reject risk in such cases, additional
algorithms are needed to identify the locations
of eyelids and eyelashes and to exclude the bits
in the resulting code from the comparison
operation - Human iris identification process is basically
divided into four steps, - Localization - The inner and the outer boundaries
of the iris are calculated. - Normalization - Iris of different people may
be captured in different size, for the
same person also size may vary because of
the variation in illumination and other
factors. - Feature extraction - Iris provides abundant
texture information. A feature vector is
formed which consists of the ordered
sequence of features extracted from the
Various representations of the iris images. - Matching - The feature vectors are classified
through different thresholding techniques like
Hamming Distance, weight vector and winner
selection, dissimilarity function, etc.
101.3 Operating Principle(Cntd.)
- Image for explaining Identification process
11Iris recognition system
12INTRODUCTION OF IRIS RECOGNITION(Cntd.)
- 1.4 Advantages
- The iris of the eye has been described as the
ideal part of the human body for biometric
identification for several reasons - It is an internal organ that is well protected
against damage and wear by a highly transparent
and sensitive membrane (the cornea). This
distinguishes it from fingerprints, which can be
difficult to recognize after years of certain
types of manual labor. - The iris is mostly flat, and its geometric
configuration is only controlled by two
complementary muscles (the sphincter pupillae and
dilator pupillae) that control the diameter of
the pupil. This makes the iris shape far more
predictable than, for instance, that of the face.
131.4 Advantages(Cntd)
- The iris has a fine texture that like
fingerprints is determined randomly during
embryonic gestation . Like the fingerprint, it is
very hard (if not impossible) to prove that the
iris is unique. However, there are so many
factors that go into the formation of these
textures (the iris and fingerprint) that the
chance of false matches for either is extremely
low. Even genetically identical individuals have
completely independent iris textures. - An iris scan is similar to taking a photograph
and can be performed from about 10 cm to a few
meters away. There is no need for the person to
be identified to touch any equipment that has
recently been touched by a stranger, thereby
eliminating an objection that has been raised in
some cultures against fingerprint scanners, where
a finger has to touch a surface, or retinal
scanning, where the eye can be brought very close
to a lens (like looking into a microscope
lens).The originally commercially deployed
iris-recognition algorithm, John Daugman's Iris
Code, has an unprecedented false match rate
141.4 Advantages(Cntd)
- While there are some medical and surgical
procedures that can affect the color and overall
shape of the iris, the fine texture remains
remarkably stable over many decades. Some Iris
identificationn have succeeded over a period
about 30 year.
15INTRODUCTION OF IRIS RECOGNITION(Cntd.)
- 1.5 Disadvantage
- Many commercial Iris scanners can be easily
fooled by a high quality image of an iris or face
in place of the real thing. - The scanners are often tough to adjust and can
become bothersome for multiple people of
different heights to use in succession. - No one is completely sure how an infrared light
could potentially damage eyesight and many feel
that it should have been heavily researched
before it was marketed and sold. The accuracy of
scanners can be affected by changes in lighting. - Iris recognition is very difficult to perform at
a distance larger than a few meters and if the
person to be identified is not cooperating by
holding the head still and looking into the
camera. However, several academic institutions
and biometric vendors are developing products
that claim to be able to identify subjects at
distances of up to 10 meters - As with other photographic biometric
technologies, iris recognition is susceptible to
poor image quality, with associated failure to
enroll rates.
16INTRODUCTION OF IRIS RECOGNITION(Cntd.)
- 1.5 History
- The history of iris recognition goes back to mid
19th-century when the French physician, Alphonse
Bertillon, studied the use of eye color as an
identifier 2. - However, it is believed that the main idea of
using iris patterns for identification, the way
we know it today, was first introduced by an eye
surgeon, Frank Burch, in 1936 6. - In 1987, two ophthalmologists, Flom and Safir,
patented this idea and proposed it to Daugman, a
professor at Harvard University, to study the
possibility of developing an iris recognition
algorithm. - After a few years of scientific experiments,
Daugman proposed and developed a high condense
iris recognition system and published the results
in 1993. The proposed system then evolved and
achieved better performance in time by testing
and optimizing it with respect to large iris
databases.
171.5 History(Cntd..)
- A few years after the publication of the First
algorithm by Daugman, other researchers developed
new iris recognition algorithms. - Systems presented by Wildes et al. 11, Boles
and Boashash , Tisse et al., Zhu et al., Lim et
al., Noh et al. and Ma et al. are some of the
well-known algorithms so far. - Among these algorithms, the works done by Lim et
al. and Noh et al. are also commercialized. - The algorithms developed by Wildes and Boles are
suitable for verification applications because
the normalization of irises is performed in the
matching process and would be very time consuming
in identification applications. - Although these algorithms have been successful,
they still require to be improved in the accuracy
and speed aspects compared to the proposed
algorithm by Daugman.
182. State of the art
- For instance, the developed algorithm by Daugman,
which is known as the state-of-the-art in the
field of iris recognition, has initiated huge
investments on the technology for more than a
decade. IriScan Inc. patents the core technology
of the Daugman's system and several companies
such as IBM, Iridian Technologies, IrisGuard
Inc., Securimetrics Inc. and Panasonic are active
in providing iris recognition products and
services. - Even though the Daugman system is the most
successful and most well known, many other
systems have been developed. The most notable
include the systems of Wildes et al., Boles and
Boashash, Lim et al., and Noh et al. - The algorithms by Lim et al. are used in the iris
recognition system developed by the Evermedia and
Senex companies. Also, the Noh et al. algorithm
is used in the IRIS2000 system, sold by
IriTech. These are, apart from the Daugman
system, the only other known commercial
implementations. -
192. State of the art (Cntd)
- The Daugman system has been tested under numerous
studies, all reporting a zero failure rate. The
Daugman system is claimed to be able to perfectly
identify an individual, given millions of
possibilities. The prototype system by Wildes et
al. also reports flawless performance with 520
iris images , and the Lim et al. system attains a
recognition rate of 98.4 with a database of
around 6,000 eye images. - Compared with other biometric technologies, such
as face, speech and finger recognition, iris
recognition can easily be considered as the most
reliable form of biometric technology . - However, there have been no independent trials of
the technology, and source code for systems is
not available. Also, there is a lack of publicly
available datasets for testing and research, and
the test results published have usually been
produced using carefully imaged irises under
favourable conditions.
203. TECHNICAL ISSUES
- 3.1 IMAGE ACQUISITION
- Why important?
- One of the major challenges of automated iris
recognition is to capture a high-quality image of
the iris while remaining noninvasive to the human
operator. - Concerns on the image acquisition rigs
- Obtained images with sufficient resolution and
sharpness - Good contrast in the interior iris pattern with
proper illumination - Well centered without unduly constraining the
operator - Artifacts eliminated as much as possible
213.1 IMAGE ACQUISITION(Cntd..)
- Image Acquisition Rigs
- a.The Daugman image-acquisition rig
22- b. The Wildes et al. image-acquisition rig
23Image Acquisition(Cntd)
- Image Acquisition Results
- Result Image from Wildes et al. rig -- capture
the iris as part of a larger image that also
contains data derived from the immediately
surrounding eye region
243.1 Image Acquisition(Cntd)
- Discussion
- In common
- Easy for a human operator to master
- Use video rate capture
- Difference.
- Operator self-position
- The Daugmans system provides the operator with
live video feedback - The Wildes et al. system provides a reticle to
aid the operator in positioning
253. TECHNICAL ISSUES(Cntd.)
- 3.2 SEGMENTATION
- In segmentation, it is desired to distinguish
the iris texture from the rest of the image. An
iris is normally segmented by detecting its inner
(pupil) and outer (limbus) boundaries. - Well-known methods such as the
Integro-differential, Hough transform and active
contour models have been successful techniques in
detecting the boundaries. In the following, these
methods are described and some of their
weaknesses are pointed out. - Iris Segmentation algorithm performed following
steps - Reflection Removal and Iris Detection
- Pupillary and Limbic Boundary Localization(Iris
Localization) - Eyelid Localization
- Eyelashes and shadow detection
263.2 SEGMENTATION(Cntd)
273.2 SEGMENTATION(Cntd)
- 3.2.1 Daugman's Integro-differential Operator
- In order to localize an iris, Daugman
proposed the Integro-differential operator. The
operator assumes that pupil and limbus are
circular contour and performs as a circular Edge
detector . Detecting the upper and lower eyelids
are also performed using the Integro-differential
operator by adjusting the contour search from
circular to a designed arcuate. The
Integro-differential is defned as - The operator pixel-wise searches throughout
the raw input image, I(x,y), and obtains the
blurred partial derivative of the integral over
normalized circular contours in different radii.
283.2.1 Daugman's Integro-differential
Operator(Cntd)
-
- The pupil and limbus boundaries are expected to
maximize the contour integral derivative, where
the intensity values over the circular b orders
would make a sudden change. Gs (r) is a smoothing
function controlled by s that smoothes the image
intensity for a more precise search.
293.2 SEGMENTATION(Cntd)
- 3.2.2 Hough Transform
- First, the image intensity information is
converted into a binary edge-map - Where
- And
- Second, the edge points vote to instantiate
particular contour parameter values -
303.2.2 Hough Transform (Cntd.)
- The voting procedure of the Wildes et al. system
is realized via Hough transforms on parametric
definitions of the iris boundary contours.
313. TECHNICAL ISSUES(Cntd.)
- 3.3 NORMALIZATION
- Normalization refers to preparing a segmented
iris image for the feature extraction pro cess.
In Cartesian co ordinates, iris images are highly
aected by their distance and angular position
with resp ect to the camera. Moreover,
illumination has a direct impact on pupil size
and causes non-linear variations of the iris
patterns. A prop er normalization technique is
exp ected to transform the iris image to comp
ensate these variations. - Methematical Tools For Normalization
- 3.3.1 Daugman's Cartesian to Polar Transform
- 3.3.2 Wildes' Image Registration
- 3.3.3 Virtual Circles
-
323. TECHNICAL ISSUES(Cntd.)
- 3.4 FEATURE ENCODING AND MATCHING
- In order to provide accurate recognition of
individuals, the most discriminating information
present in an iris pattern must be extracted.
Only the significant features of the iris must be
encoded so that comparisons between templates can
be made. - Mathematical Tools For Feature Encoding
- 3.4.1 Wavelet Encoding
- 3.4.2 Gabor Filters
- 3.4.3 Log-Gabor Filters
- 3.4.4 Zero-crossings of the 1D wavelet
- 3.4.5 Haar Wavelet
-
333.4 FEATURE ENCODING AND MATCHING(Cntd)
- The template that is generated in the feature
encoding process will also need a corresponding
matching metric, which gives a measure of
similarity between two iris templates. This
metric should give one range of values when
comparing templates generated from the same eye,
known as intra-class comparisons, and another
range of values when comparing templates created
from different irises, known as inter-class
comparisons. These two cases should give distinct
and separate values, so that a decision can be
made with high confidence as to whether two
templates are from the same iris, or from two
different irises. - Mathematical Tools For Matching
- 3.4.6 Hamming distance
- 3.4.7 Weighted Euclidean Distance
343. TECHNICAL ISSUES(Cntd.)
- 3.5 IRIS IMAGE DATABASE
- The accuracy of the iris recognition system
depends on the image quality of the iris images.
Noisy and low quality images degrade - the performance of the system.
- Some Iris image database available are
- UBIRIS
- CASIA
- LEA
- MMU
- ICE database
354. PERFORMANCE METRICS FOR IRIS RECOGNITION
- The following are used as performance metrics for
Iris Recognition systems - False accept rate or false match rate (FAR or
FMR) The probability that the system incorrectly
matches the input pattern to a non-matching
template in the database. It measures the percent
of invalid inputs which are incorrectly accepted. - False reject rate or false non-match rate (FRR or
FNMR) the probability that the system fails to
detect a match between the input pattern and a
matching template in the database. It measures
the percent of valid inputs which are incorrectly
rejected. - Fqual error rate or crossover error rate (EER or
CER) the rate at which both accept and reject
errors are equal. The value of the EER can be
easily obtained from the ROC curve. The EER is a
quick way to compare the accuracy of devices with
different ROC curves. In general, the device with
the lowest EER is most accurate. - Failure to enroll rate (FTE or FER)the rate at
which attempts to create a template from an input
is unsuccessful. This is most commonly caused by
low quality inputs
364. PERFORMANCE METRICS FOR IRIS RECOGNITION
(Cntd..)
- 6. Failure to capture rate (FTC) Within
automatic systems, the probability that the
system fails to detect a biometric input when
presented correctly. - 7. template capacity The maximum number of sets
of data which can be stored in the system.
375. APPLICATION OF IRIS RECOGNITION
- Some Current and Future Applications of Iris
Recognition - national border controls the iris as a living
passport. - computer login the iris as a living password.
- cell phone and other wireless-device-based
authentication. - secure access to bank accounts at cash machines.
- premises access control (home, office,
laboratory, etc) - driving licenses other personal certificates
- forensics birth certificates tracing missing or
wanted persons - credit-card authentication
- credit-card authentication
- anti-terrorism (e.g. security screening at
airports) - secure financial transactions (electronic
commerce, banking) - Biometric-Key Cryptography" (stable keys from
unstable templates)
386. REFERENCES
- 1 S Sanderson, J. Erbetta. Authentication for
secure environments based on iris scanning
technology. IEE Colloquium on Visual Biometrics,
2000. - 2 J.Daugman. How iris recognition works.
Proceedings of 2002 International Conference on
Image Processing, Vol. 1, 2002. - 3 E. Wolff. Anatomy of the Eye and Orbit. 7th
edition. H. K. Lewis Co. LTD,1976. - 4 R. Wildes. Iris recognition an emerging
biometric technology. Proceedings of the IEEE,
Vol. 85, No. 9, 1997. - 5 J. Daugman. Biometric personal identification
system based on iris analysis. United States
Patent, Patent Number 5,291,560, 1994. - 6 J. Daugman, High Confidence Visual
Recognition by a test of Statistical
Independence, IEEE Trans. Pattern Analysis and
Machine Intelligence, Vol. 15, No.11,
pp.1148-1161,1993. - 7 R.P.Wildes, J.C.Asmuth, G.L. Green, S.C.Hsu,
R.J,Kolczynski, J.R.Matey, S.E.McBride, David
Sarno_ Res. Center, Princeton, NJ, A System for
Automated Iris Recognition, Proceedings of the
Second IEEE Workshop on Applications of
ComputerVision,1994. - 8 W. W. Boles and B. Boashash , A Human
Identification Technique Using Images of the
Iris and Wavelet Transform, IEEE Transactions On
Signal Processing, Vol. 46, No. 4, April 1998.
396. REFERENCES (Cntd..)
- 9 S. Lim, K. Lee, O. Byeon, T. Kim. Efficient
iris recognition through improvement of feature
vector and classifier. ETRI Journal, Vol. 23, No.
2, Korea, 2001. - 10 S. Noh, K. Pae, C. Lee, J. Kim.
Multiresolution independent component analysis
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identification based on irispatterns. Proceedings
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Person identification technique using human iris - recognition. International Conference on Vision
Interface, Canada, 2002. - 13Chinese Academy of Sciences Institute of
Automation. Database of 756 Greyscale Eye Images.
http//www.sinobiometrics.com Version 1.0, 2003. - 14 C. Barry, N. Ritter. Database of 120
Greyscale Eye Images. Lions Eye Institute, Perth
Western Australia. - 15 W. Kong, D. Zhang. Accurate iris
segmentation based on novel reflection and
eyelashdetection model. Proceedings of 2001
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40End of slide