Systems and methods of eye tracking calibration

Patent metadata

Field	Value
Publication number	US-9693684-B2
Application number	US-201414180974-A
Country	US
Kind code	B2
Filing date	Feb 14, 2014
Priority date	Feb 14, 2013
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

Methods and systems to facilitate eye tracking control calibration are provided. One or more objects are displayed on a display of a device, where the one or more objects are associated with a function unrelated to a calculation of one or more calibration parameters. The one or more calibration parameters relate to a calibration of a calculation of gaze information of a user of the device, where the gaze information indicates where the user is looking. While the one or more objects are displayed, eye movement information associated with the user is determined, which indicates eye movement of one or more eye features associated with at least one eye of the user. The eye movement information is associated with a first object location of the one or more objects. The one or more calibration parameters are calculated based on the first object location being associated with the eye movement information.

First claim

What is claimed is:

1. A method comprising:
displaying a first moving object on a display of a computing device, the first moving object moving along a first path;
displaying a second moving object on the display of the computing device, the second moving object moving along a second path;
capturing images of at least one eye of a user while the first moving object and the second moving object are displayed;
while the first and second moving objects are displayed, determining, based on the images of the at least one eye captured while the first moving object and the second moving object are displayed, eye movement information associated with the user, the eye movement information indicating eye movement of one or more eye features associated with at least one eye of the user;
determining which of the first path and the second path matches the eye movement information;
associating the eye movement information with the matching path;
calculating one or more calibration parameters for the user based on a location of the matching path and the eye movement information, the one or more calibration parameters relating to a calculation of gaze information of a user of the computing device;
calculating gaze information based on the eye movement information and the one or more calibration parameters, the gaze information indicating information about where the user is looking;
in response to the associating of the eye movement information with the matching path:
changing the first path of the first moving object to a third path,
changing the second path of the second moving object to a fourth path, and
determining that the matching path corresponds to at least a portion of a login sequence of a user;

after the changing of the first path and the second path, determining second eye movement information indicating second eye movement of the one or more eye features associated with the at least one eye of the user;
determining which of the third path and the fourth path better matches the second eye movement of the one or more eye features associated with the at least one eye of the user;
associating the second eye movement information with the determined path;
determining that the determined path corresponds to a last portion in the login sequence of the user; and
based on the determination that the determined path corresponds to the last portion in the login sequence of the user, granting access to an account of the user.

2. The method of claim 1 , wherein the one or more calibration parameters comprise vertical offset or horizontal offset between optical and visual axes of the user.

3. The method of claim 1 , further comprising:
displaying a third object at a first location on the display;
displaying a fourth object at a second location on the display after the third object is displayed at the first location;
while the third object and the fourth object are displayed, determining the gaze information associated with the user;
associating the gaze information with the first location and the second location; and
adjusting the one or more calibration parameters based on the gaze information being associated with the first location and the second location.

4. The method of claim 1 , further comprising:
identifying a portion of the display of the computing device for which a calibration parameter of the one or more calibration parameters is inaccurate;
displaying the first moving object within the portion of the display; and
adjusting the one or more calibration parameters based on the first object movement being associated with the eye movement information.

5. The method of claim 4 , further comprising:
determining the gaze information based on the eye movement information and the one or more calibration parameters.

6. The method of claim 1 , wherein:
the determining of the eye movement information associated with the user includes:
determining a path of the eye movement over a plurality of frames; and
determining a velocity of the eye movement over a plurality of frames;
the first moving object moves along the first path at a first velocity;
the second moving object moves along the second path at a second velocity; and
the determining which of the first path and the second path matches the eye movement information includes:
measuring a similarity of the path of the eye movement to each of the first path and the second path; and
measuring a similarity of the velocity of the eye movement to each of the first velocity and the second velocity.

7. A non-transitory machine-readable storage medium storing instructions which, when executed by one or more processors, cause the one or more processors to perform operations comprising:
displaying a first moving object on a display of a computing device, the first moving object moving along a first path, displaying a second moving object on the display of the computing device, the second moving object moving along a second path;
capturing images of at least one eye of a user while the first moving object and the second moving object are displayed;
while the first and second moving objects are displayed, determining, based on the images of the at least one eye captured while the first moving object and the second moving object are displayed, eye movement information associated with the user, the eye movement information indicating eye movement of one or more eye features associated with at least one eye of the user;
determining which of the first path and the second path better matches the eye movement of the one or more eye features associated with the at least one eye of the user;
associating the eye movement information with the matching path;
calculating one or more calibration parameters for the user based on a location of the matching path and the eye movement information;
calculating gaze information based on the eye movement information and the one or more calibration parameters, the gaze information indicating information about where the user is looking;
in response to the associating of the eye movement information with the matching path:
changing the first path of the first moving object to a third path;
changing the second path of the second moving object to a fourth path; and
determining that the matching path corresponds to at least a portion of a login sequence of a user;

after the changing of the first path and the second path, determining second eye movement information indicating second eye movement of the one or more eye features associated with the at least one eye of the user;
determining which of the third path and the fourth path better matches the second eye movement of the one or more eye features associated with the at least one eye of the user;
associating the second eye movement information with the determined path;
determining that the determined path corresponds to a last portion in the login sequence of the user; and
based on the determination that the determined path corresponds to the last portion in the login sequence of the user, granting access to an account of the user.

8. The non-transitory machine-readable storage medium of claim 7 , wherein the instructions cause the one or more processors to perform further operations, comprising:
calculating the gaze information based on the eye movement information and the one or more calibration parameters.

9. The non-transitory machine-readable medium of claim 7 , wherein:
the determining of the eye movement information associated with the user includes:
determining a path of the eye movement over a plurality of frames; and
determining a velocity of the eye movement over a plurality of frames;

the first moving object moves along the first path at a firs

Assignees

• Facebook Inc

Inventors

• Lopez Javier San Agustin
• Hansen John Paulin
• Sztuk Sebastian
• Tall Martin Henrik

Classifications

• G06F1/1626 Primary

  with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs] · CPC title

• G06F3/013

  Eye tracking input arrangements (G06F3/015 takes precedence) · CPC title

• G06F3/038

  Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry · CPC title

• A61B3/113 Primary

  for determining or recording eye movement · CPC title

• G06F1/1632

  External expansion units, e.g. docking stations · CPC title