Thanks to the U.S. Department of Homeland Security
, digital fingerprinting is already in place for international travelers coming to the United States. The Department’s United States Visitor and Immigrant Status Indicator Technology (US-VISIT) program uses biometrics, in this case fingerprints, to verify the identities of non-U.S. citizens entering the country. The current technology can capture up to four fingerprints at a time, making the biometric verification process more accurate and efficient. However, it still requires physical contact with a scanner.
Under a program managed by the Department’s Science and Technology Directorate (S&T), the future of fingerprinting—new 3D light technology—is here. Following the 9/11 terrorist attacks, the U.S. government recognized the need for a better way to establish and verify the identities of those who might try to do the country harm. In 2004, the Department of Justice’s National Institute of Justice (NIJ)
sought advanced concepts under a program called Fast Rolled Fingerprint Capture. S&T and the University of Kentucky answered the call.
The goal: a machine that could capture all 10 fingerprints in high resolution in less than 10 seconds, without a human operator. This next generation technology ruled out procedures with inkpads or touch screens which distort a finger’s actual shape. The fingerprints of about one in 20 people (roughly 5% of the population) are too worn or damaged to be captured using contact ink-rolled fingerprinting, according to the University of Kentucky, and the ink-rolled technique takes five to 10 minutes per person.
“What we wanted was great quality as efficiently as possible,” said Michael A. Matthews, a program manager in S&T’s Infrastructure and Geophysical Division.
S&T awarded a grant to the University of Kentucky’s Center for Visualization and Virtual Environments
, which had refined a technique called structured light illumination. In this technique, a pattern of dots or stripes is projected onto a curved or irregular surface. By calculating how the pattern warps over a curve, scientists can calculate an object’s exact shape.
Using topological algorithms, software captures all of a finger’s tiny ridges recorded from three cameras and combines them into a single three-dimensional image. The 3D image is then “flattened” into a 2D virtual fingerprint that’s more precise than an ink-rolled print.
“We believe that these prints will eventually become the gold standard,” said Professor Laurence Hassebrook, the University of Kentucky’s principal investigator. Indeed, by capturing prints with depth information in 256 shades of grey, the structured-light fingerprinter will produce a higher quality of print. One of the benefits of this quality will be the ability to match prints with far greater accuracy. The software knows what a fingerprint should look like. Like PhotoShop, it can automatically align the image.
The University of Kentucky’s project goal is to project a single, continuous composite pattern and to use more cameras to capture an entire hand at once, complete with the equivalent of rolled fingerprints. Because of the enormous technical challenge of this goal, a mature version of the technology remains a few years away.
There are many potential applications for this technology. The USA Patriot Act requires fingerprinting for all Hazardous Materials Driver’s Licenses, and many states are currently passing laws to require fingerprinting for everyone applying for a driver’s license.
While the University of Kentucky project continues to work on a scanner technology that can image the whole hand at once, FlashScan3D has continued development of the structured light 3D scanning technology and has developed a two-step fingerprint reader that images four fingers, then the thumb. The FlashScan3D effort was funded by the Homeland Security Advanced Research Projects Agency (HSARPA) and S&T’s Human Factors and Behavioral Sciences Division.