Method for displaying gaze point data based on an eye-tracking unit

• US 10,635,900 B2
• Filed: 10/02/2017
• Issued: 04/28/2020
• Est. Priority Date: 01/26/2009
• Status: Active Grant

• Current Assignee: Tobii Technology AB
• Original Assignee: Tobii Technology AB
• Inventors: Strombom, Johan, Skogo, Marten, Nystedt, Per, Gustafsson, Simon, Elvesjo, John Mikael Holtz, Blixt, Peter
• Primary Examiner(s): Habib, Irfan
• Application Number:
  US15/722,971
• Publication Number:
  US 20180232575A1
• Time in Patent Office: 939 Days
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: G06V 40/19 Sensors therefor
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A method of presenting gaze-point data of a subject detected by an eye-tracking unit includes presenting a test scene picture acquired by a camera unit, and displaying shapes on the test scene picture. The shapes represent momentary gaze points of the subject.

Claims

1. A method of determining gaze points of users relative to an image of a physical space comprising:

capturing an image of a physical space;

detecting an infrared signal source located within the physical space;

determining a direction to the infrared signal source from a first user by determining an angle between an optical axis of said receiver and a line of sight between said receiver and said IR signal source;

determining a gaze direction of the first user based on information extracted from images of an eye of the person including location of a reflection on a cornea of the eye from light pulses, emitted from an IR-light-emitting device, and position of a pupil of the eye, wherein said images are acquired by a detector that is non-coaxial with the IR-light-emitting device gathered by a first eye tracking device; and

determining a gaze point of the first user in the image based on the gaze direction of the first user, the image of the physical space, and the direction to the infrared signal source from the first user.

2. The method of claim 1, further comprising:

superimposing a visual element onto the image indicating the gaze point of the first user.

3. The method of claim 2, further comprising:

determining a direction to the infrared signal source from a second user;

determining a gaze direction of the second user based on data gathered by a second eye tracking device;

determining a gaze point of the second user in the image based on the gaze direction and the direction to the infrared signal source from the second user; and

superimposing a second visual element onto the image indicating a gaze point of a second user.

4. The method of claim 1, wherein determining the gaze point of the first user comprises:

correlating the gaze direction and a location of the infrared signal source.

5. The method of claim 4, wherein correlating the gaze direction and the location of the infrared signal source comprises:

transforming the gaze direction of the first user from a reference frame of the first eye tracking device to a reference frame of the image of the physical space.

6. The method of claim 1, wherein determining the gaze point further comprises:

calibrating the gaze direction based at least in part on personal calibration data.

7. The method of claim 6, wherein the personal calibration data is selected from the group consisting of:

horizontal and vertical angles between visual and optical axes of an eye;

radius of corneal curvature; and

distance between a center of a pupil and a center of corneal curvature.

8. A system for presenting gaze points of users comprising:

a first eye tracking device;

a scene camera;

an infrared signal source located within a physical space; and

one or more processors configured to;

capture an image of the physical space with the scene camera;

detect the infrared signal source;

determine a direction to the infrared signal source from a first user by determining an angle between an optical axis of said receiver and a line of sight between said receiver and said IR signal source;

determine a gaze direction of the first user using the first eye tracking device based on information extracted from images of an eye of the person including location of a reflection on a cornea of the eye from light pulses, emitted from an IR-light-emitting device, and position of a pupil of the eye, wherein said images are acquired by a detector that is non-coaxial with the IR-light-emitting device; and

determine a gaze point of the first user in the image based on the gaze direction of the first user, the image, and the direction to the infrared signal source from the first user.

9. The system of claim 8, wherein the one or more processors are further configured to:

superimpose a visual element indicating the gaze point of the first user onto the image.

10. The system of claim 9, further comprising:

a second eye tracking device; and

one or more additional processors configured to;

detect the infrared signal source;

determine a direction to the infrared signal source from a second user;

determine a gaze direction of the second user using the second eye tracking device;

determine a gaze point of the second user in the image based on the gaze direction of the second user, the image, and the direction to the infrared signal source from the second user; and

superimpose a second visual element onto the image indicating a gaze point of the second user.

11. The system of claim 8, wherein the one or more processors determining the gaze point of the first user further comprises:

correlating the gaze direction and a location of the infrared signal source.

12. The system of claim 11, wherein correlating the gaze direction and the location of the infrared signal source comprises:

transforming the gaze direction of the first user from a reference frame of the first eye tracking device to a reference frame of the image of the physical space.

13. The system of claim 8, wherein determining a gaze point of the first user is further based on:

a location of a physical element in the image.

14. The system of claim 8, wherein the one or more processors are further configured to:

calibrate the gaze direction based at least in part on personal calibration data.

15. A non-transitory computer-readable medium having instructions stored thereon executable by a computing device to cause the computing device to perform operations comprising:

capturing an image of a physical space;

detecting an infrared signal source located within the physical space;

determining a direction from a first user to the infrared signal source by determining an angle between an optical axis of said receiver and a line of sight between said receiver and said IR signal source;

determining a gaze direction of the first user based on information extracted from images of an eye of the person including location of a reflection on a cornea of the eye from light pulses, emitted from an IR-light-emitting device, and position of a pupil of the eye, wherein said images are acquired by a detector that is non-coaxial with the IR-light-emitting device gathered by a first eye tracking device; and

determining a gaze point of the first user in the image based on the gaze direction of the first user, the image of the physical space, and the direction from the first user to the infrared signal source.

16. The non-transitory computer-readable medium of claim 15, wherein the instructions further comprise:

correlating the infrared signal source with an element in the image.

17. The non-transitory computer-readable medium of claim 15, wherein the instructions further comprise:

outputting the image with a visual element indicating the gaze point of the first user superimposed onto the image.

18. The non-transitory computer-readable medium of claim 17, wherein the instructions further comprise:

determining a direction from a second user to the infrared signal source;

determining a gaze direction of the second user based on data gathered by a second eye tracking device;

determining a gaze point of the second user in the image based on the gaze direction of the second user, the image of the physical space, and the direction from the second user to the infrared signal source; and

superimposing a second element onto the image indicating a gaze point of a second user.

19. The non-transitory computer-readable medium of claim 15, wherein the instructions further comprise:

determining a location of a physical element in the image; and

wherein determining the gaze point of the first user in the image is further based on the location of the physical element in the image.

20. The non-transitory computer-readable medium of claim 15, wherein the instructions further comprise:

relating a location of the infrared signal source with a reference frame of a camera used to capture the image of the physical space using hardware calibration data.