There are two methods used to assess faces. One is the "fiducial" method, shown below, which hunts for distinctive features in a face, often where the bone structure is most apparent. Measurements are taken at these nodal points to give a map of the face. These points make up a numerical code called the faceprint.This code is then compared to other codes in the database to see if there is a match.
Some measurements taken:
- Distance between the eyes: A-B
- Shape of the cheekbones: C-D-E
- Width of the nose: F-G
- Length of the jaw line: H-I-J
The other method looks for pixels that resemble a face, shown above. The face is then compared to an extensive database to reveal demographic information about that individual. This method is being used more and more in digital advertising.
Intel's anonymous video analytics can process millions of pixels per second as it searches for pixels that make up a human face. In the first tenth of a second, it analyses the faces for age and gender, logs the information and sends it across the Internet to an online application. Within the second that follows, the display can update itself to match its target audience, hawking, say, action-movie DVDs for a group of young males, or luxury vacations for an older female.