The United States Patent and Trademark Office has published a patent filing by iPhone maker Apple that outlines a method of face recognition for taking an iOS device out of sleep mode.

With the new feature, to be incorporated in future version of iOS, users will be able to turn on their phone or devices automatically by utilising the camera to scan the user’s face.

The new method will recognise unique facial features as well as specific skin tones to recognise a face.

Though the software memorises the facial features of a user, the user may have to reset the scan after any form of facial change done due to surgery or sunburn.

The company is expected to utilise and customise the current face detection technology in the iPhone 4S for photography, to meet this unique requirement.

Designed to work in many situations, the new technology is called "low threshold face recognition" by Apple.

According to Google, however, the facial recognition technology is less secure than using a pin or other password to lock or unlock a device.