Grant Evans beams a smile as he ponders the potential of his company's 3-D face-recognition technology.
The upbeat chief executive of A4Vision sees huge sales of cameras, hardware and software on the horizon as the Sunnyvale start-up joins the global push to boost security since the Sept. 11 terror attacks.
Face scanning has emerged as one of the hottest "biometric" methods for identifying people. The goal is to use unique body parts -- such as fingerprints, irises or face or hand patterns -- to help identity someone as friend or suspected foe.
"What I say is, `It's tough to leave home without your face,' " Evans said.
Evans and others selling face-scanning gear say their systems are merely computers that mimic the natural way for humans to recognize one another -- by faces.
Reality, though, is more complex and controversial.
Privacy advocates fear a day when police could monitor someone almost constantly through a network of security cameras.
The potential applications are many: A soldier gazes into a camera mounted to a door to a restricted building on a base. The computer searches through a database of those allowed to enter, and clicks open the door once the familiar face is found. Or, travelers at a border crossing line up to look into the camera to prove they are the person listed on their passport.
Organizations from the U.S. Department of Defense to the airport in Lyon, France, are testing or using new 3-D face-recognition technology. But older 2-D face-recognition technology, sold by biometric leaders like Identix of Minnesota, is still the norm. Current international technology standards -- key to lucrative deals for passports or other government programs -- support 2-D systems.
Vendors of 3-D face systems such as A4Vision or rival Geometrix of San Jose must wade through a multinational thicket of laws, regulations and technology standards before potentially lucrative customers, such as government visa programs, can make 3-D technology mainstream.
They must also prove their technology is truly more accurate than less expensive 2-D systems, especially for wide-area surveillance in public places such as airports and casinos.
Don't expect concrete answers for now. Although 3-D would appear to offer some advantages, large-scale testing isn't complete.
"It's so new," said David Fisch, a consultant for the Independent Biometric Group, an independent New York research organization. "It gives you more data points, adding depth, and therefore you should have higher accuracy."
With A4Vision's 3-D system, it takes up to eight seconds to enroll a person into a database of faces. First, the subject's face is covered by an infrared light pattern that shows the face's geometry, which is captured on streaming video.
That face pattern is then plugged into an algorithm to generate a 3-D "mesh" created from measurements smaller than a millimeter.
A biometric template -- based on bone structures that don't change with aging -- is then created from the image and is stored in the database. After enrollment, the face of a person approaching the custom 3-D camera is matched with the image stored in the database.
Companies that make 2-D face-recognition systems think their approach is still superior.
The 2-D face technology has an advantage over 3-D because it is cheaper and easier to set up, said Joseph Atick, president and CEO of Identix. The company's software analyzes the distances between features such as the nose, mouth and the size of the eyes. Identix also has a new "skin biometric," in which it uses an algorithm to study the skin of the face, looking for differences between skin textures.
Atick sees wide applications for 2-D face technology, namely for scanning databases with millions of images such as government visa programs or state driver's licenses. In September, the U.S. State Department selected Identix to provide technology for its visa-processing program -- a deal worth $2.2 million in its first 12 months.
A4Vision's Evans countered that 3-D systems are not as dependent on ideal light, camera angles or factors such as facial hair. He added that the more expensive 3-D makes sense as customers upgrade their hardware to include more sophisticated security cameras.
Both Identix and A4Vision claim their systems are accurate enough to distinguish between identical twins.
But both have their shortcomings. Something as simple as a toothy smile -- considered "an extreme facial expression" -- can throw off either kind of recognition system.
The entire face-scanning industry is still reeling from the black eye of several failed test programs in recent years.
In one trial in 2002, a 2-D face-recognition system at Boston's Logan International Airport -- where two planes used in the Sept. 11 attacks departed -- failed to identify 39 percent of volunteers who had their images stored in the experiment's database.
"They were failures," said Atick, whose 2-D company was involved in the Logan trial. "Actually, they were good lessons for the industry, and the industry has since learned from those."
Results are improving. A U.S. government test of face systems released in 2003 found that 2-D systems correctly identified 90 percent of people who had their images stored in the database in "controlled indoor" settings, according to the Face Recognition Vendor Test of 2002. The study also found that 1 percent of the matches made were "false positives" -- the computer identified the person being scanned as a different person stored in the database.
The 2005 test is looking at 3-D scanning, but results are not yet available.
Fisch said face-scanning is still not as accurate as fingerprinting or iris scans. "Both the 2-D and 3-D need to prove they have high accuracy before they are going to have widespread deployment," he said.
But face-scanning companies say their systems are easy to use on large crowds at airports and border crossings because they don't require cooperation from the user, such as touching a fingerprint reader. They add that many people don't want to give their fingerprints because that method is associated with being a criminal.
Cameras are everywhere in modern society -- a fact that delights some and scares others.
The American Civil Liberties Union says the widespread use of face scanning could bring Big Brother-like government surveillance, where a person could be tracked by ubiquitous cameras posted in airports, shopping malls and other public areas.
"It's going to result in people being asked to account for their whereabouts all the time," Barry Steinhardt, director of the Technology and Liberty Program at the ACLU, said of the technology.
He added that law enforcement potentially could follow a person from the airport, to the shopping mall, to other public places where cameras are mounted. He sees potential abuse: "Why is that black man in the white neighborhood?"
Those selling face-scanning gear downplay those fears.
Miami International Airport has about 2,000 cameras providing security, said Jonathan Forrester, director of marketing for AWT, a Georgia-bases system integrator for security systems that sells Geometrix's face-scanning equipment.
He added that an "average citizen" in New York City may be captured by as many as 75 security cameras over the course of a day. Such systems, Forrester said, could protect people from identify theft or could help nab criminals or terrorists.
Added Atick of Identix: "The ACLU has taken the stance that the technology is bad. Society has a right to determine where it's needed. We have cops, but we don't deploy them in the bedroom."
Evans sees the technology becoming more widely accepted. A4Vision -- which still collects around 65 percent of its revenue from test programs, not actual deployments -- is backing a proposed international standard for 3-D technology. It's a process that he said should take no more than two years.
In the meantime, he knows what customers want: "Speed is everything with this. Accuracy is everything with this."