3D GAZE TRACKER

• US 20120147328A1
• Filed: 12/13/2010
• Published: 06/14/2012
• Est. Priority Date: 12/13/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Yahav, Giora
• Granted Patent: US 8,408,706 B2
• Time in Patent Office: Days
• US Class Current: 351/210
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06V 40/19 Sensors therefor
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/383 for tracking with gaze detection, i.e. detecting the lines of sight of the viewer's eyes

Abstract

An embodiment of the invention provides a gaze tracker for determining a gaze vector for a person, which comprises a 3D camera that and a picture camera that image the person and a controller that processes images acquired by the cameras to determine a gaze direction and origin for the gaze vector.

Claims

1. A gaze tracker for determining a gaze vector having a direction and origin for a person, the gaze tracker comprising:

a 3D camera that acquires a range image of a person located in a field of view (FOV) of the camera;

a picture camera that acquires a picture of the person in the FOV of the 3D camera; and

a controller that processes the range image and the picture to determine spatial coordinates for features of the person'"'"'s head and an eye of the person, and determines a gaze direction and origin for a gaze vector of the eye.

2. A gaze tracker according to claim 1, wherein the FOV extends to a distance from the gaze tracker equal to or greater than about 1 m.

3. A gaze tracker according to claim 1, wherein the FOV extends to a distance from the gaze tracker equal to or greater than about 2 m.

4. A gaze tracker according to claim 1, wherein the FOV extends to a distance from the gaze tracker equal to or greater than about 3 m.

5. A gaze tracker according to claim 1, wherein the FOV extends from a distance from the gaze tracker equal to about 0.3 m.

6. A gaze tracker according to claim 1 and comprising a light source that illuminates at least a portion of the FOV.

7. A gaze tracker according to claim 6 wherein the controller adjusts intensity of light provided by the light source responsive to a spatial coordinate determined by the controller.

8. A gaze tracker according to claim 6 wherein the controller adjusts direction of light provided by the light source responsive to a spatial coordinate determined by the controller.

9. A gaze tracker according to claim 1, wherein the features comprise at least one feature of the person'"'"'s eye for which spatial coordinates can be used to determine gaze direction of the eye.

10. A gaze tracker according to claim 9, wherein the at least one feature of the eye comprises at least one of the pupil, iris, sclera, and a Purkinje reflection.

11. A gaze tracker according to claim 1, wherein the features comprise at least one feature of the person'"'"'s head for which spatial coordinates can be used to determine orientation of the head.

12. A gaze tracker according to claim 11, wherein the at least one feature of the head comprises the forehead, an eye, the nose, lips chin, and an ear.

13. A gaze tracker according to claim 1, wherein the 3D camera comprises a stereoscopic camera.

14. A gaze tracker according to claim 1, wherein the 3D camera comprises a time of flight (TOF) 3D camera.

15. A gaze tracker according to claim 14, wherein the TOF 3D camera and the picture camera comprise different photosensors comprising pixels on which they image light to respectively acquire the range image and picture.

16. A gaze tracker according to claim 15, wherein pixels in the different photosensors have different sizes.

17. A gaze tracker according to claim 16, wherein pixels in the photosensor on which the 3D camera images light are larger than pixels in the photosensor on which the picture camera images light.

18. A gaze tracker according to claim 15 and comprising optics for adjusting magnification of imaging on the photosensors independently of each other.

19. A gaze tracker according to claim 18 wherein the controller adjusts magnification responsive to a spatial coordinate determined by the controller.

20. A method of determining a gaze direction of a person, the method comprising:

acquiring a range image of a person that provides distances to the person'"'"'s features;

acquiring a contrast image of the person; and

processing the range image and the contrast image to provide a gaze vector for the person that defines a direction along which the person is looking.