Iris recognition
Encyclopedia
Biometrics
Biometrics As Jain & Ross point out, "the term biometric authentication is perhaps more appropriate than biometrics since the latter has been historically used in the field of statistics to refer to the analysis of biological data [36]" . consists of methods...
identification that uses mathematical pattern-recognition techniques on video images of the irides
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
of an individual's eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
s, whose complex random patterns are unique and can be seen from some distance.
Not to be confused with another, less prevalent, ocular-based technology, retina scanning, iris recognition uses camera technology with subtle infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
illumination to acquire images of the detail-rich, intricate structures of the iris. Digital templates encoded from these patterns by mathematical and statistical algorithms allow unambiguous positive identification of an individual. Databases of enrolled templates are searched by matcher engines at speeds measured in the millions of templates per second per (single-core) CPU, and with infinitesimally small False Match rates.
Many millions of persons in several countries around the world have been enrolled in iris recognition systems, for convenience purposes such as passport-free automated border-crossings, and some national ID systems based on this technology are being deployed. A key advantage of iris recognition, besides its speed of matching and its extreme resistance to False Matches, is the stability of the iris as an internal, protected, yet externally visible organ of the eye.
The core algorithms that underlie iris recognition were developed in the 1990's by Professor John Daugman
John Daugman
John Daugman is a physicist and Professor of Computer Vision and Pattern Recognition at the University of Cambridge Computer Laboratory. He is best known for his pioneering work in biometric identification, in particular the development of the Gabor wavelet based iris recognition algorithm that is ...
, Ph.D, OBE (University of Cambridge Computer Laboratory
University of Cambridge Computer Laboratory
The Computer Laboratory is the computer science department of the University of Cambridge. As of 2007, it employs 35 academic staff, 25 support staff, 35 affiliated research staff, and about 155 research students...
). These were licensed to many developers of commercial iris cameras and systems including LG Electronics, Oki, Panasonic, Sagem, IrisGuard, and Sarnoff Labs. As of 2008, Daugman's algorithms are the basis of all commercially deployed iris recognition systems, although many alternative approaches have been studied and compared in the academic literature in hundreds of publications. Iris recognition remains a very active research topic in computing, engineering, statistics, and applied mathematics.
Visible Wavelength (VW) vs Near Infrared (NIR) Imaging
The majority of iris recognition cameras use Near Infrared (NIR) imaging by emitting 750nm wavelength low-power light. This is done because dark-brown eyes, possessed by the majority of the human population, reveal rich structure in the NIR but much less in the visible band (400 - 700nm), and also because NIR light is invisible and unintrusive. A further important reason is that by allowing only this selected narrow band of illuminating light back into the camera via its filters, most of the ambient corneal reflections from a bright environment are blocked from contaminating the iris patterns.The melanin, also known as chromophore, mainly consists of two distinct heterogeneous macromolecules, called eumelanin (brown–black) and pheomelanin (yellow–reddish). NIR imaging is not sensitive to these chromophores, and as a result they do not appear in the captured images. In contrast, visible wavelength (VW) imaging keeps the related chromophore information and, compared to NIR, provides rich sources of information mainly coded as shape patterns in iris. Hosseini, et al. provide a comparison between these two imaging modalities and fused the results to boost the recognition rate. An alternative feature extraction method to encode VW iris images was also introduced, which is highly robust to reflectivity terms in iris. Such fusion results are seemed to be alternative approach for multi-modal biometric systems which intend to reach high accuracies of recognition in large databanks.
| Visible Wavelength Iris Image | Near Infrared (NIR) version |
|---|---|
Operating principle
Gabor filter
In image processing, a Gabor filter, named after Dennis Gabor, is a linear filter used for edge detection. Frequency and orientation representations of Gabor filters are similar to those of the human visual system, and they have been found to be particularly appropriate for texture representation...
transform is used. The result is a set of complex numbers that carry local amplitude and phase information about the iris pattern. In Daugman's algorithms, most amplitude information is discarded, and the 2048 bits representing an iris pattern consist of phase information (complex sign bits of the Gabor wavelet projections). Discarding the amplitude information ensures that the template remains largely unaffected by changes in illumination or camera gain (contrast), and contributes to the long-term usability of the biometric template. For identification (one-to-many template matching) or verification (one-to-one template matching), a template created by imaging an iris is compared to stored template(s) in a database. If the Hamming distance
Hamming distance
In information theory, the Hamming distance between two strings of equal length is the number of positions at which the corresponding symbols are different...
is below the decision threshold, a positive identification has effectively been made because of the statistical extreme improbability that two different persons could agree by chance ("collide") in so many bits, given the high entropy
Entropy
Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...
of iris templates.
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 corneaCorneaThe cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
). 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.
- The iris has a fine texture that—like fingerprints—is determined randomly during embryonic gestationGestationGestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
. 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 being 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 must be brought very close to an eyepiece (like looking into a microscope).
- The commercially deployed iris-recognition algorithm, John DaugmanJohn DaugmanJohn Daugman is a physicist and Professor of Computer Vision and Pattern Recognition at the University of Cambridge Computer Laboratory. He is best known for his pioneering work in biometric identification, in particular the development of the Gabor wavelet based iris recognition algorithm that is ...
's IrisCode, has an unprecedented false match rate (better than 10−11 if a Hamming distance threshold of 0.26 is used, meaning that up to 26% of the bits in two IrisCodes are allowed to disagree due to imaging noise, reflections, etc., while still declaring them to be a match).
- While there are some medical and surgical procedures that can affect the colour and overall shape of the iris, the fine texture remains remarkably stable over many decades. Some iris identifications have succeeded over a period of about 30 years.
Shortcomings
- 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.
- The accuracy of scanners can be affected by changes in lighting
- Iris scanners are significantly more expensive than some other forms of biometrics, password or prox card security systems
- Iris scanning is a relatively new technology and is incompatible with the very substantial investment that the law enforcement and immigration authorities of some countries have already made into fingerprint recognition.
- 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 ("standoff iris" or "iris at a distance" as well as "iris on the move" for persons walking at speeds up to 1 meter/sec).
- As with other photographic biometric technologies, iris recognition is susceptible to poor image quality, with associated failure to enroll rates.
- As with other identification infrastructure (national residents databases, ID cards, etc.), civil rights activists have voiced concerns that iris-recognition technology might help governments to track individuals beyond their will.
Security considerations
As with most other biometric identification technology, a still not satisfactorily solved problem with iris recognition is the problem of live-tissue verification. The reliability of any biometric identification depends on ensuring that the signal acquired and compared has actually been recorded from a live body part of the person to be identified and is not a manufactured template. Many commercially available iris-recognition systems are easily fooled by presenting a high-quality photograph of a face instead of a real face, which makes such devices unsuitable for unsupervised applications, such as door access-control systems. The problem of live-tissue verification is less of a concern in supervised applications (e.g., immigration control), where a human operator supervises the process of taking the picture.Methods that have been suggested to provide some defence against the use of fake eyes and irises include:
- Changing ambient lighting during the identification (switching on a bright lamp), such that the pupillary reflexPupillary reflexThe pupillary light reflex is a reflex that controls the diameter of the pupil, in response to the intensity of light that falls on the retina of the eye, thereby assisting in adaptation to various levels of darkness and light, in addition to retinal sensitivity...
can be verified and the iris image be recorded at several different pupilPupilThe pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. In humans the pupil is round, but other species, such as some cats, have slit pupils. In...
diameters - Analysing the 2D spatial frequency spectrum of the iris image for the peaks caused by the printer ditherDitherDither is an intentionally applied form of noise used to randomize quantization error, preventing large-scale patterns such as color banding in images...
patterns found on commercially available fake-iris contact lenses - Analysing the temporal frequency spectrum of the image for the peaks caused by computer displays
- Using spectral analysisSpectrometerA spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization...
instead of merely monochromatic cameras to distinguish iris tissue from other material - Observing the characteristic natural movement of an eyeball (measuring nystagmus, tracking eye while text is read, etc.)
- Testing for retinal retroreflection (red-eye effectRed-eye effectThe red-eye effect in photography is the common appearance of red pupils in color photographs of eyes. It occurs when using a photographic flash very close to the camera lens , in ambient low light. The effect appears in the eyes of humans and animals that have no tapetum lucidum, hence no...
) - Testing for reflections from the eye's four optical surfaces (front and back of both cornea and lens) to verify their presence, position and shape
- Using 3D imaging (e.g., stereo cameras) to verify the position and shape of the iris relative to other eye features
A 2004 report by the German Federal Office for Information Security
Federal Office for Information Security
The Bundesamt für Sicherheit in der Informationstechnik is the German government agency in charge of managing computer and communication security for the German government...
noted that none of the iris-recognition systems commercially available at the time implemented any live-tissue verification technology. Like any pattern-recognition technology, live-tissue verifiers will have their own false-reject probability and will therefore further reduce the overall probability that a legitimate user is accepted by the sensor.
Deployed applications
- United Arab EmiratesUnited Arab EmiratesThe United Arab Emirates, abbreviated as the UAE, or shortened to "the Emirates", is a state situated in the southeast of the Arabian Peninsula in Western Asia on the Persian Gulf, bordering Oman, and Saudi Arabia, and sharing sea borders with Iraq, Kuwait, Bahrain, Qatar, and Iran.The UAE is a...
IrisGuard's Homeland Security Border Control has been operating an expellee tracking system in the United Arab Emirates (UAE) since 2001, when the UAE launched a national border-crossing security initiative. Today, all of the UAE's land, air and sea ports of entry are equipped with systems. All foreign nationals who possess a visa to enter the UAE are processed through iris cameras installed at all primary and auxiliary immigration inspection points. To date, the system has apprehended over 330,000 persons re-entering the UAE with fraudulent travel documents.
- Aadhar, India's UID project uses Iris scan along with fingerprints to uniquely identify people and allocate a Unique Identification Number.
- Iris is one of three biometric identification technologies internationally standardized by ICAOInternational Civil Aviation OrganizationThe International Civil Aviation Organization , pronounced , , is a specialized agency of the United Nations. It codifies the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth...
for use in future passports (the other two are fingerprint and face recognition)
- Iris recognition technology has been implemented by BioID Technologies SA in PakistanPakistanPakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
for UNHCR repatriation project to control aid distribution for Afghan refugees. Refugees are repatriated by UNHCR in cooperation with Government of Pakistan, and they are paid for their travel. To make sure people do not get paid more than once, their irises are scanned, and the system will detect the refugees on next attempt. The database has more than 1.3 million iris code templates and around 4000 registrations per day. The one-to-many iris comparison takes place within 1.5 seconds against 1.3 million iris codes.
- At Schiphol Airport, NetherlandsNetherlandsThe Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
, iris recognition has permitted passport-free immigration since 2001.
- Used to verify the recognition of the "Afghan Girl" (Sharbat GulaSharbat GulaSharbat Gula is an Afghan woman who was the subject of a famous photograph by journalist Steve McCurry. Gula was living as a refugee in Pakistan during the time of the Soviet occupation of Afghanistan when she was photographed...
) by National Geographic photographer Steve McCurry. See http://www.cl.cam.ac.uk/~jgd1000/afghan.html
- In a number of US and Canadian airports, as part of the NEXUSNEXUS (frequent traveller program)NEXUS is a joint Canada-United States program designed to let pre-approved, low-risk travelers cross the US-Canada border quickly. Members of the program can avoid long waits at border entry points by using self-serve kiosks at airports, reserved lanes at land crossings, or by phoning border...
program that facilitates entry into the US and Canada for pre-approved, low-risk travelers.
- In several Canadian airports, as part of the CANPASS Air program that facilitates entry into Canada for pre-approved, low-risk air travelers.
- GoogleGoogleGoogle Inc. is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products, and generates profit primarily from advertising through its AdWords program...
use iris scanners to control access to their datacentres.
- On May 10, 2011, Hoyos Group demonstrated a device called EyeLock using iris-recognition as an alternative to passwords to log people in to password-protected Web sites and applications, like Facebook or eBay.
Iris recognition in fiction
- In Demolition ManDemolition Man (film)Demolition Man is a 1993 American, science fiction action film directed by Marco Brambilla, and starring Sylvester Stallone and Wesley Snipes. Sandra Bullock, Nigel Hawthorne, and Denis Leary co-star....
(1993), a character played by Wesley SnipesWesley SnipesWesley Trent Snipes is an American actor, film producer, and martial artist, who has starred in numerous action films, thrillers, and dramatic feature films. Snipes is known for playing the Marvel Comics character Blade in the Blade film trilogy, among various other high profile roles...
uses the Warden's gouged eye to gain access through a security door. - In Dan BrownDan BrownDan Brown is an American author of thriller fiction, best known for the 2003 bestselling novel, The Da Vinci Code. Brown's novels, which are treasure hunts set in a 24-hour time period, feature the recurring themes of cryptography, keys, symbols, codes, and conspiracy theories...
's 2000 novel Angels and DemonsAngels and DemonsAngels & Demons is a 2000 bestselling mystery-thriller novel written by American author Dan Brown and published by Pocket Books. The novel introduces the character Robert Langdon, who is also the protagonist of Brown's subsequent 2003 novel, The Da Vinci Code, and 2009 novel, The Lost Symbol...
, an assassin gains access to a top secret CERNCERNThe European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
laboratory using a scientist's eye. - Steven SpielbergSteven SpielbergSteven Allan Spielberg KBE is an American film director, screenwriter, producer, video game designer, and studio entrepreneur. In a career of more than four decades, Spielberg's films have covered many themes and genres. Spielberg's early science-fiction and adventure films were seen as an...
's 2002 science fictionScience fictionScience fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
film Minority ReportMinority Report (film)Minority Report is a 2002 American neo-noir science fiction film directed by Steven Spielberg and loosely based on the short story "The Minority Report" by Philip K. Dick. It is set primarily in Washington, D.C...
depicts a society in which what appears to be a form of iris recognition has become daily practice. The principal character undergoes an eye transplant in order to change his identity but continues to use his original eyes to gain access to restricted locations. - In The Island (2005), a human clone character played by Ewan McGregorEwan McGregorEwan Gordon McGregor is a Scottish actor. He has had success in mainstream, indie, and art house films. McGregor is perhaps best known for his roles as heroin addict Mark Renton in the drama Trainspotting , young Jedi Obi-Wan Kenobi in the Star Wars prequel trilogy , and poet Christian in the...
uses his eye to gain access through a security door of the original's house. - The Simpsons MovieThe Simpsons MovieThe Simpsons Movie is a 2007 American animated comedy film based on the animated television series The Simpsons. The film was directed by David Silverman, and stars the regular television cast of Dan Castellaneta, Julie Kavner, Nancy Cartwright, Yeardley Smith, Hank Azaria, Harry Shearer, Tress...
(2007) features a scene that illustrates the difficulty of image acquisition in iris recognition.http://www.cl.cam.ac.uk/~jgd1000/simpsons.html - Numb3rsNUMB3RSNumb3rs is an American television drama which premiered on CBS on January 23, 2005, and concluded on March 12, 2010. The series was created by Nicolas Falacci and Cheryl Heuton, and follows FBI Special Agent Don Eppes and his mathematical genius brother, Charlie Eppes , who helps Don solve crimes...
features a scene where a robber gets into the CalSci facility by cracking the code assigned to a specific iris. - NCISNCIS (TV series)NCIS, formerly known as NCIS: Naval Criminal Investigative Service, is an American police procedural drama television series revolving around a fictional team of special agents from the Naval Criminal Investigative Service, which conducts criminal investigations involving the U.S...
uses an iris scanner in the garage, where forensic vehicle investigations are carried out and evidence is stored. There is another scanner at the entrance to MTAC. The sequence of Leroy Jethro GibbsLeroy Jethro GibbsLeroy Jethro Gibbs is a fictional character and the main protagonist of the CBS TV series NCIS. He is portrayed by Mark Harmon.-Background:...
being verified is shown in the title sequence.
See also
- Biometric technology in access control
- Iris Recognition Immigration SystemIris Recognition Immigration SystemIris Recognition Immigration System is an initiative to provide automated clearance through UK immigration for certain frequent travellers...
- Finger Vein recognitionFinger Vein recognitionFinger vein recognition is a method of biometric authentication that uses pattern-recognition techniques based on images of human finger vein patterns beneath the skin's surface...
- Fingerprint recognition
External links
- Home page of IrisCode designer John Daugman
- ISO/IEC 19794-6 International standard for iris images
- NIST Iris Challenge Evaluation – a contest for competing iris-recognition algorithms
- NIST IREX – a program for various NIST activities supporting interoperable iris biometrics, including comparison of 19 state-of-the-art iris recognition algorithms from 10 providers
- Iris recognition test results, analysis
- Iris recognition algorithm reidentifies Sharbat Gula – Afghan National Geographic cover girl in 1985 – two decades later
- Bath University Iris Image Database
- John G. Daugman's original patent application at Google PatentsGoogle PatentsGoogle Patents is a search engine from Google that indexes patents and patent applications from the United States Patent and Trademark Office , which are taken from the original USPTO database . All 8 million patents have been put in the database. Optical character recognition has been...
- World largest current deployment
- Project Iris an Open Source iris recognition system