Multi-frame depth image information identification

A handheld device for authenticating a user to the handheld device, the system comprising:

• a processor;
• a depth camera;
• and
• computer storage media having computer-executable instructions embodied thereon, that when executed by the processor, cause the handheld device to perform a method, the method comprising:
• (1) capturing, with the depth camera, a series of images of at least a portion of a head of the user;
• (2) identifying a first attribute within the series of images;
• (3) determining the user is an authorized user of the device based, at least in part, on the first attribute;
• and
• (4) providing a first functionality of the device to the user in response to determining the user is an authorized user.

One or more computer storage media having computer-executable instructions embodied thereon, that when executed by a computing system having a processor and memory, cause the computing system to perform a method of authenticating a user of a device, the method comprising:

• capturing an image sequence of a user with a camera coupled with a device, wherein each image of the image sequence is comprised of depth information;
• identifying, with the processor, a first facial gesture in three dimensional space captured in the image sequence;
• identifying, with the processor, a second facial gesture captured in three dimensional space in the image sequence;
• determining the first facial gesture corresponds with a first authorizing gesture;
• and
• determining, with the processor, the user is an authorized user of the device.