Apple has filed a patent, which describes the application of face detection function for user authentication of mobile devices.
The principle of operation are based on comparison with the previously obtained image stored in memory with the image coming from the camera. Recognition feature examines the degree of similarity of the most features characteristic , such as eye and contours of mouth. The result of comparison is used to select a user profile and access to the device.
The principle is similar to the development Android Face Unlock.