Facial recognition is a method of identifying an individual’s identity. It is a type of biometric security, it is extremely useful in law enforcement. Face recognition systems may use 3D or 2D software. Visible light and infrared are used in this process. The software starts by finding the eyes and repositioning the facial image to be front facing.
It works by taking a picture of a face. The software then reads the geometry of the face and determines the distance between the eyes, the depth of the eye sockets, the distance from forehead to chin, the shape of the cheekbones, and the contour of the lips, ears, and chin. These are key landmarks for identifying an individual’s face. These measurements are transformed into digital information. Your face’s analysis is essentially a maths formula. The answer to this is unique to you, just as your fingerprints are unique.
Humans are very unique individuals, even our underlying skeleton has unique features. The shape of the skull gives the basis for facial recognition. The skull can be divided into the neurocranium and viscerocranium. The neurocranium includes the superior bones of the skull, surrounding the brain and the viscerocranium refers to the bones that make up the jaw and lower face. Muscles are stretched across the bones of the face. Variation in facial appearance is due to the variations in the size and shape of an individual's facial bones and how the overlying muscles and skin are attached to them.
22 bones make up the adult skull. These bones are fused together, however at birth they are not. This is to allow the foetus to pass out of the birth canal and allows the brain to rapidly expand and grow.
The viscerocranium is composed of the maxilla, nasal, zygomatic, lacrimal, palatine, and inferior nasal concha. These bones give the face its shape.
There are many different face shapes and sizes. Most people's heads can be considered to be dolichocephalic, meaning they have a long and narrow head with a protruding nose, mesocephalic where the length of the head is proportionate to its width, or brachycephalic, where the head is short and wide with a short nose.
Variations are also influenced by sex. Men tend to have larger faces. Women's faces are flatter than men's this is due to men being more likely to have a protruding forehead, deep-set eyes, and less prominent cheekbones.
As well as face shape, the shape of eyes, lips, and ears are considered in facial recognition. These shapes can be due to ethnicity or in the instances of ears, genetic. Whether ear lobes are attached or not is due to genetics.
A wide variety of companies use facial recognition and have a large database. Apple use it for unlocking their newest phones, airports use it for confirming passport identification and national security keep a record of faces to help in identifying criminals.