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.