Using facial data for device authentication or subject identification

A mobile device having a processor and memory, the mobile device being configured to perform operations comprising:

• receiving an indication of a request by a user to unlock the mobile device from a locked state;
• capturing one or more images of the face of the user as the face of the user is illuminated by a light source;
• extracting facial components of the user from the one or more captured images;
• determining whether the user is an authorized user based at least in part on a comparison of the facial components of the user extracted from the one or more captured images to facial components of the authorized user from at least one of two or more authentication images of the authorized user stored on the mobile device;
• unlocking the mobile device if the user is determined to be the authorized user;
• and
• maintaining the locked state of the mobile device if the user is determined not to be the authorized user,
• wherein the capturing includes prompting the user to make a randomly selected facial expression or head motion, and
• wherein the two or more authentication images include at least one authentication image of the user making the facial expression or head motion that is randomly selected.

One or more computer-readable storage or memory devices storing computer-executable instructions which when executed by a computer cause the computer to perform authentication operations comprising:

• receiving an indication of a request by a user to unlock a computing device in a locked state;
• capturing one or more images of the face of the user as the face of the user is illuminated by a light source;
• extracting facial components of the user from the one or more captured images;
• determining whether the user is an authorized user based at least in part on a comparison of the facial components of the user extracted from the one or more captured images to facial components of the authorized user from two or more authentication images of the authorized user stored on the mobile device, wherein the two or more authentication images are taken under substantially different lighting intensities, at least one image of the user being taken in a low-lighting situation;
• unlocking the mobile device if the user is determined to be the authorized user;
• and
• maintaining the locked state of the mobile device if the user is determined not to be the authorized user,
• wherein the capturing comprises capturing a plurality of consecutive frames of the user as the user is making a head movement, and
• wherein the method further comprises performing a detection technique using the plurality of consecutive frames to determine that the face of the user is a real face and not a two-dimensional representation of the face of the user.

A method, comprising:

• receiving an indication of a request by a user to unlock a mobile device in a locked state;
• capturing one or more images of the face of the user as the face of the user is illuminated by a light source, wherein the capturing is facilitated through an image capture screen of the mobile device in which a first portion of the image capture screen is dedicated to providing the light source that illuminates the face of the user and a second portion of the image capture screen displays an image currently being received by a camera of the mobile device;
• extracting facial components of the user from the one or more captured images;
• determining whether the user is an authorized user based at least in part on a comparison of the facial components of the user extracted from the one or more captured images to one or more facial components of the authorized user obtained respectively from one or more authentication images of the authorized user stored on the mobile device;
• unlocking the mobile device if the user is determined to be the authorized user;
• and
• maintaining the locked state of the mobile device if the user is determined not to be the authorized user.