Face biometrics

Principles of face biometrics

The dimensions, proportions and physical attributes of a person's face are unique.

How does face biometrics work

Biometric facial recognition systems will measure and analyze the overall structure, shape and porportions of the face: Distance between the eyes, nose, mouth, and jaw edges; upper outlines of the eye sockets, the sides of the mouth, the location of the nose and eyes, the area surrounding the cheekbones.

At enrolment, several pictures are taken of the user's face, with slightly different angles and facial expressions, to allow for more accurate matching. For verification and identification, the user stands in front of the camera for a few seconds, and the scan is compared with the template previously recorded.

To prevent an image / photo of the face or a mask from being used, face biometric systems will require the user to smile, blink, or nod their head. Also, facial thermography can be used to record the heat of the face (which won't be affected by a mask).

The main facial recognition methods are: feature analysis, neural network, eigenfaces, and automatic face processing.

Benefits of face biometric systems

• Not intrusive, can be done from a distance, even without the user being aware of it (for instance when scanning the entrance to a bank or a high security area).

Weaknesses of face biometric systems

• Face biometric systems are more suited for authentication than for identification purposes, as it is easy to change the proportion of one's face by wearing a mask, a nose extension, etc.
• User perceptions / civil liberty: Most people are incomfortable with having their picture taken.

Applications of face biometrics

Access to restricted areas and buildings, banks, embassies, military sites, airports, law enforcement.