Differentiating real faces from representations

Patent metadata

Field	Value
Publication number	US-9524421-B2
Application number	US-201314100704-A
Country	US
Kind code	B2
Filing date	Dec 9, 2013
Priority date	Dec 9, 2013
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

Facial recognition can be used to determine whether or not a user has access privileges to a device such as a smartphone. It may be possible to spoof an authenticated user's image using a picture of the user. Implementations disclosed herein utilize time of flight and/or reflectivity measurements of an authenticated user to compare to such values obtained for an image of an object. If the time of flight distance and/or reflectivity distance for the object match a measured distance, then the person (i.e., object) may be granted access to the device.

First claim

The invention claimed is:

1. A method, comprising:
emitting light from a device toward an object;
capturing an image of the object using a sensor, comprising receiving the light by the sensor;
identifying at least two landmarks within the image of the object;
determining a number of pixels in the image disposed between the at least two landmarks;
determining a measured distance between the device and the object based on the number of pixels;
determining a reflectivity distance between the device and the object based on an amount of light received by the sensor;
determining a time of flight distance between the device and the object;
comparing the time of flight distance, the reflectivity distance, and the measured distance;
determining whether the object is authorized to operate the device based on the comparison of the time of flight distance, the reflectivity distance, and the measured distance; and
providing an access level to the device based on the determination of whether the object is authorized to operate the device.

2. The method of claim 1 , wherein the access level to the device comprises a locked state if the object is determined to be unauthorized to operate the device.

3. The method of claim 1 , wherein the light is emitted for a predetermined interval.

4. The method of claim 1 , further comprising:
obtaining a profile for a first face of a user authorized to operate the device; and
generating a profile for the object.

5. The method of claim 4 , wherein the determination of whether the object is authorized to operate the device is further based on a comparison of the profile for the first face and the profile for the object.

6. The method of claim 5 , wherein the level of access provided to the device is further based on the comparison of the profile for the first face and the profile for the object.

7. The method of claim 1 , wherein the determination of the time of flight distance is based on a time interval from when the light was emitted from the device and when the sensor received the light.

8. A device, comprising:
an image capture device comprising at least one light emission module and at least one sensor;
wherein the at least one light emission module is configured to emit light from the device toward an object;
wherein the at least one sensor is configured to capture an image of the object by receiving at least a portion of the light emitted by the light emission module; and

a processor configured to:
determine a reflectivity distance between the device and the object based on an amount of light received by a sensor;
determine a time of flight distance between the device and the object;
identify at least two landmarks within an image of the object;
determine a number of pixels in the image disposed between the at least two landmarks;
determine a measured distance between the device and the object based on the number of pixels;
compare the reflectivity distance, the time of flight distance, and the measured distance;
determine whether the object is authorized to operate the device based on the comparison of the reflectivity distance, the time of flight distance, and the measured distance; and
provide an access level to the device based on the determination of whether the object is authorized to operate the device.

9. The device of claim 8 , wherein the access level to the device comprises a locked state if the object is determined to be unauthorized to operate the device.

10. The device of claim 8 , wherein the light is emitted for a predetermined interval.

11. The device of claim 8 , the processor further configured to:
obtain, by the device, a profile for a first face of a user authorized to operate the device; and
generate a profile for the object.

12. The device of claim 11 , wherein the determination of whether the object is authorized to operate the device is further based on a comparison of the profile for the first face and the profile for the object.

13. The device of claim 12 , wherein the level of access provided to the device is further based on the comparison of the profile for the first face and the profile for the object.

14. A method, comprising:
emitting, by a device, light toward a plurality of locations on an object;
capturing, by the device, the light reflected from the plurality of locations on the object;
determining, by the device, a first time of flight from when the light was emitted from the device, reflected from a first location of the plurality of locations, and captured by the device;
determining, by the device, a second time of flight from when the light was emitted from the device, reflected from a second location of the plurality of locations, and captured by the device;
comparing, by the device, the first time of flight to a first corresponding time of flight associated with a profile of an authorized user of the device;
comparing, by the device, the second time of flight to a second corresponding time of flight associated with the profile of the authorized user of the device;
determining, by the device, a level of access to the device based on the comparison of the first time of flight to the first corresponding time of flight and the comparison of the second time of flight to the second corresponding time of flight; and
providing, by the device, the level of access to the device.

Assignees

• Google Inc

Inventors

• Ross Steven James
• Williams Brian Patrick
• Schneiderman Henry Will
• Nechyba Michael Christian

Classifications

• G06K9/00288 Primary

  Physics · mapped topic

• G06F21/32 Primary

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

• G06K9/00268

  Physics · mapped topic

• G06V40/168

  Feature extraction; Face representation · CPC title

• G06V40/172 Primary

  Classification, e.g. identification · CPC title