Reliability of gaze tracking data for left and right eye

Patent metadata

Field	Value
Publication number	US-9940518-B1
Application number	US-201715700878-A
Country	US
Kind code	B1
Filing date	Sep 11, 2017
Priority date	Sep 11, 2017
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

Circuitry of a gaze/eye tracking system obtains one or more images of a left eye and one or more images a right eye, determines a gaze direction of the left eye based on at least one obtained image of the left eye, determines a gaze direction of the right eye based on at least one obtained image of the right eye, determines a first confidence value based on the one or more obtained images of the left eye, determines a second confidence value based on the one or more obtained images of the right eye, and determines a final gaze direction based at least in part on the first confidence value and the second confidence value. The first and second confidence values represent indications of the reliability of the determined gaze directions of the left eye and the right eye, respectively. Corresponding methods and computer-readable media are also provided.

First claim

What is claimed is:

1. An eye/gaze tracking system comprising circuitry, wherein the circuitry is configured to:
obtain one or more images of a left eye of a user and one or more images of right eye of the user;
determine a gaze direction of the left eye of the user based on at least one obtained image of the left eye;
determine a gaze direction of the right eye of the user based on at least one obtained image of the right eye;
determine a first confidence value based on the one or more obtained images of the left eye, the first confidence value representing an indication of a reliability of the determined gaze direction of the left eye;
determine a second confidence value based on the one or more obtained images of the right eye, the second confidence value representing an indication of a reliability of the determined gaze direction of the right eye; and
determine a final gaze direction based at least in part on the first confidence value and the second confidence value.

2. The eye/gaze tracking system of claim 1 , wherein determining the final gaze direction is further based on the determined gaze direction of the left eye and the determined gaze direction of the right eye.

3. The eye/gaze tracking system of claim 1 , wherein determining the final gaze direction is further based on a weighted combination of the determined gaze direction of the left eye and the determined gaze direction of the right eye.

4. The eye/gaze tracking system of claim 1 , wherein the circuitry is further configured to:
determine, based on the one or more obtained images of the left eye, one or more glint positions in a predetermined region of the left eye; and
determine, based on the one or more obtained images of the right eye, one or more glint positions in a predetermined region of the right eye.

5. The eye/gaze tracking system of claim 4 , wherein the predetermined region of the left or right eye includes at least one of:
a first region that extends from a cornea center to an edge of a spherical region of the cornea;
a second region that extends from the edge of the spherical region of the cornea to an edge of the cornea; or
a third region that is located outside of the edge of the cornea.

6. The eye/gaze tracking system of claim 5 , wherein the third region is located at a sclera.

7. The eye/gaze tracking system of claim 1 , wherein:
determining the first confidence value based on the one or more obtained images of the left eye comprises determining the first confidence value based on a distance between a cornea center of the left eye and one or more glints at the left eye; and
determining the second confidence value based on the one or more obtained images of the right eye comprises determining the second confidence value based on a distance between a cornea center of the right eye and one or more glints at the right eye.

8. The eye/gaze tracking system of claim 7 , wherein:
determining the first confidence value based on the one or more obtained images of the left eye further comprises:
associating glints located at a first region of the left eye with a higher reliability than a reliability associated with glints located at a second region of the left eye, wherein the first region of the left eye extends from a cornea center to an edge of a spherical region of the cornea, and wherein the second region of the left eye extends from the edge of the spherical region of the cornea to an edge of the cornea; and
associating glints located at the second region of the left eye with a higher reliability than a reliability associated with glints located in a third region of the left eye, wherein the third region of the left eye is located outside of the edge of the cornea; and

determining the second confidence value based on the one or more obtained images of the right eye further comprises:
associating glints located at a first region of the right eye with a higher reliability than a reliability associated with glints located in a second region of the right eye, wherein the first region of the right eye extends from a cornea center to an edge of a spherical region of the cornea, and wherein the second region of the right eye extends from the edge of the spherical region of the cornea to an edge of the cornea; and
associating glints located at the second region of the right eye with a higher reliability than a reliability associated with glints located in a third region of the right eye, wherein the third region of the right eye is located outside of the edge of the cornea.

9. The eye/gaze tracking system of claim 1 , wherein the circuitry is further configured to:
determine a pupil center of the left eye, a pupil center of the right eye, an eyeball center of the left eye, and an eyeball center of the right eye.

10. The eye/gaze tracking system of claim 5 , wherein the cornea center is a position at the spherical region of the cornea where a virtual line extending from the eyeball center through the pupil center intersects the spherical region of the cornea.

11. The eye/gaze tracking system of claim 1 , wherein:
determining the first confidence value based on the one or more obtained images of the left eye further comprises:
determining the first confidence value based on a contrast between a pupil and an iris of the left eye; and
associating a first level of said contrast with a lower reliability than a reliability associated with a second level of said contrast, wherein the first level of said contrast is lower than the second level of said contrast; and

determining the second confidence value based on the one or more obtained images of the right eye further comprises:
determining the second confidence value based on a contrast between a pupil and an iris of the right eye; and
associating a first level of said contrast with a lower reliability than a reliability associated with a second level of said contrast, wherein the first level of said contrast is lower than the second level of said contrast.

12. The eye/gaze tracking system of claim 1 , wherein:
determining the first confidence value based on the one or more obtained images of the left eye further comprises:
determining the first confidence value based on a first aggregation level of determined gaze positions of the left eye with respect to a predetermined position at a display apparatus, and

determining the second confidence value based on the one or more obtained images of the right eye further comprises:
determining the second confidence value based on a second aggregation level of determined gaze positions of the right eye with respect to a predetermined position on a display apparatus.

13. The eye/gaze tracking system of claim 1 , wherein:
determining the first confidence value based on the one or more obtained images of the left eye further comprises:
determining the first confidence value based on a first distance between a predetermined position at a display apparatus and an average of determined gaze positions of the left eye, and

determining the second confidence value based on the one or more obtained images of the right eye further comprises:
determining the second confidence value based on a second distance between a predetermined position at a display apparatus and an average of determined gaze positions of the right eye.

14. The eye/gaze tracking system of claim 1 , wherein the determination of the first confidence value or the second confidence value, respectively, is based on at least one of:
a glint intensity at the left eye or the right eye, respectively;
a shape of glints at the left eye or the right eye, respectively; or
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Assignees

• Tobii Ab

Inventors

• Klingström Andreas
• Kuldkepp Mattias
• Skogö Mårten

Classifications

• G06T2207/30201

  Face · CPC title

• G06T7/60

  Analysis of geometric attributes · CPC title

• G06T7/74

  involving reference images or patches · CPC title

• G06T7/13

  Edge detection · CPC title

• G06K9/2054

  Physics · mapped topic