Using facial data for device authentication or subject identification

Patent metadata

Field	Value
Publication number	US-9652663-B2
Application number	US-201514791055-A
Country	US
Kind code	B2
Filing date	Jul 2, 2015
Priority date	Jul 12, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

Exemplary methods, apparatus, and systems are disclosed for authenticating a user to computing device. In one exemplary embodiment, an indication of a request by a user to unlock a mobile device in a locked state is received. One or more images of the face of the user are captured. Facial components of the user from the one or more captured images are extracted. A determination is made as to whether the user is an authorized user or a non-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 one or more authentication images of the authorized stored on the mobile device. If the user is determined to be the authorized user, the mobile device unlocked; otherwise, the mobile device is maintained in its locked state.

First claim

We claim:

1. 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.

2. The mobile device of claim 1 , further comprising, in an enrollment phase in which the two or more authentication images are created, capturing a series of images of the user making different facial expressions or head motions, the user being prompted to make each different facial expression or head motion during the enrollment phase.

3. The mobile device of claim 1 , wherein the capturing comprises capturing two or more images of the face of the user in succession, and
wherein the determining comprises determining whether the user is the authorized user based at least in part on a comparison of the facial components of the user extracted from the two or more captured images to the facial components of the authorized user from the two or more authentication images stored on the mobile device.

4. The mobile device of claim 1 , wherein the capturing comprises capturing a plurality of consecutive frames of the user as the user is making a head movement, and
wherein the operations further comprise 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.

5. The mobile device of claim 4 , wherein the detection technique determines whether the face of the user is a real face and not a two-dimensional representation of the face of the user by, in part, estimating an affine transform between the consecutive frames.

6. The mobile device of claim 4 , wherein the detection technique determines whether the face of the user is a real face and not a two-dimensional representation of the face of the user by a process comprising:
detecting the face of the user in the consecutive frames;
tracking one or more feature points on the detected face over the consecutive frames;
estimating affine transforms between respective ones of the consecutive frames;
measuring residuals between the affine transform estimates; and
determining whether the face is real or fake based on the residuals.

7. 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 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,
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,
the method further comprising pre-processing the one or more captured images to compensate for lighting conditions in which the one or more images are captured, wherein the pre-processing comprises downsampling the one or more images of the face of the user to a lower resolution, and wherein the extracting and determining are performed using the downsampled one or more images.

8. The mobile device of claim 7 , wherein the detection technique determines whether the face of the user is a real face and not a two-dimensional representation of the face of the user by, in part, estimating an affine transform between the consecutive frames.

9. The mobile device of claim 7 , wherein the detection technique determines whether the face of the user is a real face and not a two-dimensional representation of the face of the user by a process comprising:
detecting the face of the user in the consecutive frames;
tracking one or more feature points on the detected face over the consecutive frames;
estimating affine transforms between respective ones of the consecutive frames;
measuring residuals between the affine transform estimates; and
determining whether the face is real or fake based on the residuals.

10. The mobile device of claim 7 , wherein the comparison is performed by generating feature descriptors representative of the facial components of the user in the one or more captured images, and determining a difference between the feature descriptors of the user in the one or more captured images and respective facial descriptors of the authorized user generated from the two or more authentication images.

11. The mobile device of claim 7 , wherein the comparison is performed by generating a graph-based representation of the facial components of the user in the one or more captured images, and determining a difference between the graph-based representation of the facial components of the user and respective graph-based representations of the authorized user generated from the two or more authentication images,
the graph-based representation of the facial components of the user being indicative of appearances and relative geometric relationships of the facial components of the user.

12. The mobile device of claim 7 , wherein the determining comprises:
if the facial components of the user extracted from the one or more captured images match the facial components of the authorized user from the two or more authentication images, generating an indication that the user is authorized; and
if the facial components of the user extracted from the one or more captured images do not match the facial components of the authorized user from the two or more authentication images, causing a secondary authentication method to be performed on the mobile device.

13. 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 f

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Lau James Kai Yu
• Kaheel Ayman
• El-Saban Motaz
• Shawky Mohamed
• Gonzalez Monica
• El Baz Ahmed
• Deif Tamer
• Aly Alaa Abdel-Hakim

Classifications

• G06F21/32 Primary

  using biometric data, e.g. fingerprints, iris scans or voiceprints · CPC title

• G06V40/168

  Feature extraction; Face representation · CPC title

• H04N23/74

  by influencing the scene brightness using illuminating means · CPC title

• G06V10/422

  for representing the structure of the pattern or shape of an object therefor · CPC title

• G06F21/31

  User authentication · CPC title