The Application of Biometric Technologies:
“The Afghan Girl-Sharbat Gula”
By Ravi Das is the President of HTG Advance Systems
Overview of Previous Article
Our last article reviewed the concept of biometrics, and the biometric technologies that are available today (hand geometry, fingerprint, voice/speech, iris/retinal, and face recognition), as well as the biometric technologies that are being planned for the future (earlobe, brain mapping, odor, and gait recognition). Finally, an example was provided which explained some of the scientific and engineering concepts behind biometric technology. This article will focus upon a very dramatic application of biometric technology—namely iris recognition and how it was used to find the Afghan Girl, Sharbat Gula.
The Technology Behind Iris Recognition
Iris recognition technology is very safe to use, and has widespread commercial applications, as discussed in the previous article. Iris recognition focuses upon examining the unique features of the iris. The iris is the colored region between the pupil and the white region of the eye (also called the sclera), and its primary purpose is to control the size of the pupil (the part of the eye which light enters into). The unique features of the iris include the trabecular meshwork (this is the tissue that gives the iris its “radial” impression), as well as other physiological properties such as the freckles, furrows, rings, and the corona.
An iris recognition camera first recognizes the iris. A black and white image of the iris is then captured, from which the unique features (as defined in the previous paragraph) are identified, including the orientation, frequency, and position. These are then converted into vectors, which form the basis for the enrollment and verification templates. These templates are called IrisCode ® records, which are 512 bytes. The iris recognition technology can take into consideration many different kinds of variables, such as pupil dilation, reflections from the iris recognition camera, etc.
The foundation behind iris recognition technology is a series of mathematical algorithms developed by Dr. John Daugman of the University of Cambridge. These algorithms are derived from a procedure called Gabor Wavelet Theory. Iridian Technologies, Inc. (based in Moorestown, New Jersey) has patented this technology, and is right now the primary vendor for iris based biometric technology.
Iris recognition technology is deemed to be among the most stable and reliable of the biometric technologies available today. This is so because the structure of the iris rarely changes during the lifetime of the individual, and also because no two irises are alike. For example, tests have concluded that the iris structure is different between the right and left eyes of people, and even in identical twins.
The History Behind the Picture of Sharbat Gula
The famous picture of the striking, green eyes of Sharbat Gula goes back for 17 years, to 1985. She is originally from Afghanistan. During the time of the Soviet Union invasion of Afghanistan, she and her family fled into the Nasir Bagh refugee camp, located in Peshawar, Pakistan. During this time, a world famous photographer from National Geographic Magazine, Steve McCurry, came to this region to capture the plight of the Afghanistan refugees on pictures. One of the refugees he met and took pictures of was Sharbat Gula, when she was only 13 years old. Steve McCurry did not know her name, or anything else about her family. Of the many pictures he took of her, one stood out in particular-her piercing, green eyes. During the course of the next 17 years, this picture became world famous, appearing in books, magazines, newspapers, posters and other forms of media. Sharbat Gula knew nothing of her fame until she met Steve McCurry for the second time in January 2002.
Finding Sharbat Gula 17 Years Later
In January 2002, Steve McCurry returned to the same region in a final attempt to locate Sharbat Gula. Steve McCurry and his team searched through numerous villages and came across various leads which proved to be false. Finally, the break came when an individual came forward and claimed that Sharbat Gula was a next door neighbor many years ago. After several days of making this claim, this same individual brought back the brother of Sharbat Gula, who had the same color eyes. From that moment onwards, McCurry and his team felt that they had located the family of Sharbat Gula.
Because of her culture, Sharbat Gula was not allowed to meet other men. However, a female producer of National Geographic was allowed to initially meet with and take photographs of her. Finally, after a series of “negotiations” with her family, Steve McCurry was able to see Sharbat Gula. After asking some questions and comparing the world famous photograph to photographs just taken of her, Steve McCurry felt he had finally found the Afghan Girl-17 years later. However, various tests had to be conducted-in order to make sure that Sharbat Gula was truly the Afghan Girl.
Positively Identifying Sharbat Gula
Numerous tests were conducted to confirm the identity of Sharbat Gula. Two sophisticated tests were utilized: Facial recognition techniques developed by forensic examiners at the FBI, and iris recognition techniques developed by Dr. John Daugman and Iridian Technologies, Inc. The pictures taken in 1985 were compared to the pictures taken in 2002, in both tests. The facial recognition techniques confirmed her identity, however the ultimate test came down to iris recognition because of its reliability, as stated before in this article. However, the scientists at Iridian Technologies, Inc. had to overcome a number of obstacles. First, the pictures taken by National Geographic of Sharbat Gula were not taken by iris recognition cameras, rather they were taken with other types of cameras. As a result, the scientists had to eliminate the effects of the light reflections produced by these cameras, and also make various modifications to the image quality of these photographs. The pictures of Sharbat Gula were then eventually scanned into a digital format. Second, iris recognition works by examining scans from live subjects, not static photographs-another major obstacle. After making a series of adjustments to the iris recognition software, the scientists concluded that Sharbat Gula was positively the Afghan Girl- “The match of Sharbat Gula’s eyes to the eyes on the 1985 cover photo was irrefutable, as we achieved a 1 in 100 million probability of a false match. There is no doubt in my mind that National Geographic has found the girl in the cover photo.” (Ulf Cahn von Seelen, Director of Algorithms, Iridian Technologies, Inc. Note: This is a direct quote taken from the Biometric Digest, April 2002 publication).
It should be noted that iris recognition technology is also being utilized in Afghanistan to identify refugees seeking humanitarian aid.
Our next article will examine another real world application of biometric technology-how fingerprint recognition is used to reduce check fraud.
Note: IrisCode is a registered trademark of Iridian Technologies, Inc.
About the Author:
Ravi Das is the President of HTG Advance Systems, which is the security solutions division of HTG Solutions, based in Chicago, IL.
Please visit the website at www.htgadvancesystems.com. The author can be contacted biometrics@htgadvancesystems.co
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