Reflector-based depth mapping of a scene

• US 9,204,121 B1
• Filed: 11/26/2012
• Issued: 12/01/2015
• Est. Priority Date: 11/26/2012
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Marason, Eric G., Coley, Christopher D., Weatherford, William Thomas
• Primary Examiner(s): Harold, Jefferey
• Assistant Examiner(s): DESIR, JEAN WICEL
• Application Number:
  US13/685,535
• Time in Patent Office: 1,100 Days
• Field of Search: 348/42, 348/36, 348/46, 348/51, 348/56, 348/49, 348/135, 345/419
• US Class Current: 1/1
• CPC Class Codes: G01B 11/2513 with several lines being projected in more than one direction, e.g. grids, patterns
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G06T 7/55 from multiple images
• CPC Class Codes: H04N 13/106 Processing image signals for multi-view video sequence encoding H04N19/597
• CPC Class Codes: H04N 13/271 wherein the generated image signals comprise depth maps or disparity maps
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 5/141 Beam current control means

Abstract

The depth of one or more objects within a scene may be determined utilizing system that includes a single light source, a reflector (e.g., an ellipsoidal reflector), a shutter mechanism associated with the light source, and a camera. More particularly, the light source may output light that is directed towards the scene (a first set of light beams) and towards the reflector (a second set of light beams) utilizing the shutter mechanism. The reflector may reflect the second set of light beams towards the scene. The camera may then capture a first image that corresponds to the first set of light beams and a second image that corresponds to the second set of light beams. The depth of a particular one of the objects within the scene may be determined based at least in part on the first image and the second image.

Claims

1. A system comprising:

a light source configured to output light beams within a physical space;

a shutter mechanism associated with the light source and configured to selectively cause;

a first set of the light beams from the light source to be directed towards the physical space and away from an ellipsoidal reflector, the first set of light beams illuminating the physical space at a first time; and

a second set of the light beams from the light source to be directed towards the ellipsoidal reflector and away from the physical space, the ellipsoidal reflector reflecting the second set of light beams towards the physical space such that the second set of light beams as reflected by the ellipsoidal reflector illuminates the physical space at a second time;

a camera configured to capture a first image of the physical space at the first time and a second image of the physical space at the second time; and

a depth determination module configured to generate a depth map of the physical space based at least in part on the first image and the second image, the depth map being used to determine a depth of an object within the physical space.

2. The system as recited in claim 1, wherein the depth of the object is determined based at least in part on a distance between a first focus and a second focus, the first focus being associated with the first set of light beams and being determined from the first image and the second focus being associated with the second set of light beams and being determined from the second image.

3. The system as recited in claim 2, wherein the first focus represents a first point corresponding to a location where the first set of light beams are emitted by the light source and the second focus represents a second point corresponding to where the second set of light beams converge in response to being reflected by the ellipsoidal reflector.

4. The system as recited in claim 2, wherein a first illumination of the physical space at the first time differs from a second illumination of the physical space at the second time based at least in part on the first focus and the second focus.

5. A method comprising:

outputting a first set of light beams towards a physical space;

capturing a first image of the physical space at a first time corresponding to when the first set of light beams are output towards the physical space or after the first set of light beams are output towards the physical space;

outputting a second set of light beams towards a reflector, the second set of light beams being redirected onto the physical space by the reflector;

capturing a second image of the physical space at a second time corresponding to when the second set of light beams are redirected onto the physical space by the reflector or after the second set of light beams are redirected onto the physical space by the reflector; and

determining a depth of an object within the physical space based at least in part on a comparison between the first image and the second image.

6. The method as recited in claim 5, wherein the first set of light beams and the second set of light beams are alternately or selectively output using a shutter mechanism associated with a light source.

7. The method as recited in claim 5, further comprising:

generating a depth map based at least in part on the first image and the second image;

and wherein the determining the depth of the object within the physical space comprises determining the depth of the object based at least in part on the depth map, the depth map providing information relating to spatial relationships between the object and other objects within the physical space.

8. The method as recited in claim 5, wherein the determining the depth of the object within the physical space is based at least in part on a distance between a first focus and a second focus, and wherein:

the first focus is associated with the first set of light beams and is determined from the first image, the first focus representing a first point corresponding to where the first set of light beams are emitted by a light source; and

the second focus is associated with the second set of light beams and is determined from the second image, the second focus representing a second point corresponding to where the second set of light beams converge in response to being redirected towards the physical space by the reflector.

9. The method as recited in claim 8, wherein the physical space is illuminated by the first set of light beams at the first time, wherein the physical space is illuminated by the second set of light beams at the second time, and further comprising:

determining a ratio of a first illumination level of the physical space associated with the first image and a second illumination level of the physical space associated with the second image; and

determining the depth of the object within the physical space based at least in part on the ratio.

10. The method as recited in claim 5, wherein the second set of light beams are redirected towards the physical space by an ellipsoidal reflector that is associated with a light source that outputs the first set of light beams and the second set of light beams.

11. A method comprising:

outputting a first set of light beams and a second set of light beams within a physical space, the second set of light beams being redirected towards the physical space by an ellipsoidal reflector;

determining a distance between a first focus and a second focus, the first focus corresponding to the first set of light beams and the second focus corresponding to the second set of light beams; and

determining a depth of an object within the physical space based at least in part on the distance.

12. The method as recited in claim 11, further comprising:

outputting, by a light source, the first set of light beams and the second set of light beams; and

directing, by a shutter mechanism associated with the light source, the first set of light beams towards the physical space and the second set of light beams towards the ellipsoidal reflector.

13. The method as recited in claim 11, further comprising causing, by a shutter mechanism, the first set of light beams and the second set of light beams to illuminate the physical space from two coaxial points corresponding to the first focus and the second focus.

14. The method as recited in claim 11, further comprising:

capturing a first image of the physical space as illuminated by the first set of light beams;

capturing a second image of the physical space as illuminated by the second set of light beams; and

determining the depth of the object based at least in part on the first image and the second image.

15. The method as recited in claim 14, wherein the depth of the object within the physical space is based at least in part on a ratio of the distance between the first focus and the second focus and an illumination associated with each of the first image and the second image.

16. The method as recited in claim 14, further comprising:

generating a depth map of the physical space based at least in part on the first image and the second image; and

determining the depth of the object based at least in part on the depth map.

17. A system comprising:

a light source configured to output light beams within a physical space;

a shutter mechanism associated with the light source and configured to cause the light source to alternatively output a first set of the light beams that are directed towards the physical space and a second set of the light beams that are directed towards an ellipsoidal reflector, the ellipsoidal reflector reflecting the second set of light beams towards the physical space;

a camera configured to capture a first image of the physical space at a first time that corresponds to when the first set of light beams are output or after the first set of light beams are output and a second image of the physical space at a second time that corresponds to when the second set of light beams are reflected by the ellipsoidal reflector or after the second set of light beams are reflected by the ellipsoidal reflector; and

a depth determination module configured to determine a depth of an object within the physical space based at least in part on the first image and the second image.

18. The system as recited in claim 17, wherein the light source is a single light source, and wherein the depth of the object within the physical space is determined without moving the light source.

19. The system as recited in claim 17, wherein the depth of the object within the physical space is determined based at least in part on a first focus associated with the first set of light beams and a second focus associated with the second set of light beams.

20. The system as recited in claim 19, wherein the physical space is illuminated by the first set of light beams at the first focus and by the second set of light beams at the second focus.

21. The system as recited in claim 17, wherein a type of the camera corresponds to a type of light output by the light source.

22. The system as recited in claim 17, wherein the camera is synchronized with the shutter mechanism so that the camera captures the first image when the physical space is illuminated by the first set of light beams and captures the second image when the physical space is illuminated by the second set of light beams.