Face unlock requires Ice Cream Sandwich, if your device is running an older version of Android, you can search to see if there is an update available. If you already have an ICS device, you need to access the settings page by pressing the menu key on a home screen and tapping the ‘Settings’ button.
Scroll down the settings page and look for either ‘Lock screen’ or ‘Security’. Some devices have the lock screen function separately while others have it under Security.
The Lock screen page has all the options related to your screen; for instance, you can choose to lock the screen automatically after the screen turns off. On the same page lock for the Screen Lock option, which allows you to change the screen unlock methods.
The screen lock page should list all the available methods, including Password, Pattern, PIN and Face unlock. Tap the Face unlock option to proceed.
You will get a warning message next, asking you not to use face unlock while driving. Tap the next button to proceed.
The next screen will have useful information for you. It will inform you of the feature’s shortcomings such as the fact that it is less secure than pattern, pin or password locks. It also states that someone who looks similar to you can unlock your device. Tap the ‘Set it up’ button to proceed.
You will see tips on the next page, advising you to find a spot which is not too bright or too dim and holding the phone at eye level. Tap ‘Continue’.
Now you will see your camera view on the screen (using your front camera) and a dotted outline, where you need to place your face (in terms of the view finder). Once your face is within the outline, the dotted line will show progress and a confirmation message in the end. Tap ‘Continue’ again.
You can choose an alternate method to unlock your device in case your face is not recognized (due to a bug or improper lighting). This will ensure that you are not locked out of your device.
Now you can test the face unlock by holding the phone at eye level and trying to unlock it using your face.