Identity and Expression

(Part of the biometric product marketing expert series)

Whether you are a human or a non-person entity (NPE) with facial recognition capability, you rely on visual cues to positively identify or authenticate a person. Let’s face it; many people resemble each other, but specific facial expressions or emotions are not always shared by people who otherwise look alike.

But in one of those oddities that fill the biometric world, you can have TOO MUCH expression. Part 3 of International Civil Aviation Organization (ICAO) Document 9303, which governs machine readable travel documents, mandates that faces on travel documents must maintain a neutral expression without smiling. At the time (2003) it was believed that the facial recognition algorithms would work best if the subject were expressionless. I don’t know if that holds true today.

But once the smile is erased, any other removal of expression or emotion degrades identification capability significantly. For example, closing the eyes not only degrades facial recognition, but is obviously fatal to iris recognition.

And if you remove the landmarks upon which facial recognition depends, identification is impossible.

While expression or lack thereof does not invalidate the assumption of permanence of the biometric authentication factor, it does govern the ability of people and machines to perform identification or authentication.