Facial recognition

One of the oldest and most basic examples of a characteristic that is used for recognition is the face. Since the beginning of civilization, humans have used faces to identify known (familiar) and unknown (unfamiliar) individuals.

Face recognition is a nonintrusive method, and facial images are probably the most common biometric characteristic used by humans to make a personal recognition. The applications of facial recognition range from a static, controlled “mug-shot” verification to a dynamic, uncontrolled face identification in a cluttered background (airport). The most popular approaches to face recognition are based on either:

  • the location and shape of facial attributes such as the eyes, eyebrows, nose, lips and chin, and their spatial relationships, or
  • the overall (global) analysis of the face image that represents a face as a weighted combination of a number of canonical faces.

While the verification performance of the face recognition systems that are commercially available is reasonable, they impose a number of restrictions on how the facial images are obtained, sometimes requiring a fixed and simple background or special illumination. These systems also have difficulty in recognizing a face from images captured from two drastically different views and under different illumination conditions. It is questionable whether the face itself, without any contextual information, is a sufficient basis for recognizing a person from a large number of identities with an extremely high level of confidence. In order for a facial recognition system to work well in practice, it should automatically:

  • detect whether a face is present in the acquired image;
  • locate the face if there is one; and
  • recognize the face from a general viewpoint (from any pose).

Facial recognition can be used not just to identify an individual, but also to unearth other personal data associated with an individual (photos featuring the individual, blog posts, social networking profiles, digital behaviour, travel patterns) all through facial features alone, and it is likely that data obtained during biometric enrolment may be used in ways for which the enrolled individual has not consented.

Countries using biometrics include Australia, Brazil, Canada, Cyprus, Greece, China, Gambia, Germany, India, Iraq, Israel, Italy, Malaysia, Netherlands, New Zealand, Nigeria, Norway, Pakistan, South Africa, Saudi Arabia, Tanzania, Ukraine, United Arab Emirates, United Kingdom, United States and Venezuela.