Here you can find the answer: Face recognition
Every face has numerous, distinguishable landmarks, the different peaks and valleys that make up facial features. FaceIt defines these landmarks as nodal points. Each human face has approximately 80 nodal points. Some of these measured by the software are:
* Distance between the eyes
* Width of the nose
* Depth of the eye sockets
* The shape of the cheekbones
* The length of the jaw line
These nodal points are measured creating a numerical code, called a faceprint, representing the face in the database.
