Image exposure using exclusion regions

• US 8,786,730 B2
• Filed: 08/18/2011
• Issued: 07/22/2014
• Est. Priority Date: 08/18/2011
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Tardif, John, Panchapagesan, Seshagiri
• Primary Examiner(s): LAM, HUNG H
• Application Number:
  US13/212,927
• Publication Number:
  US 20130044222A1
• Time in Patent Office: 1,069 Days
• Field of Search: 348/187, 348/229.1, 348/255, 348/208.12, 348/345, 348/362
• US Class Current: 348/229.1
• CPC Class Codes: H04N 17/002 for television cameras

Abstract

Calculating a gain setting for a primary image sensor includes receiving a test-matrix of pixels from a test image sensor, and receiving a first-frame matrix of pixels from a primary image sensor. A gain setting is calculated for the primary image sensor using the first-frame matrix of pixels except those pixels imaging one or more exclusion regions identified from the test matrix of pixels.

Claims

1. A method of calculating a gain setting for a primary image sensor, the method comprising:

receiving a test matrix of pixels from a test image sensor;

receiving a first-frame matrix of pixels from the primary image sensor; and

calculating a gain setting for the primary image sensor using the first-frame matrix of pixels except those pixels imaging one or more exclusion regions identified from the test matrix of pixels.

2. The method of claim 1, where calculating a gain setting includes constructing a histogram of the first-frame matrix of pixels except the pixels imaging the one or more exclusion regions.

3. The method of claim 1, further comprising applying the calculated gain setting to the primary sensor for subsequent matrices of pixels.

4. The method of claim 1, where each pixel in the first-frame matrix includes visible light information indicating an intensity of visible light observed at that pixel.

5. The method of claim 1, where each pixel in the test matrix includes infrared light information indicating an intensity of infrared light observed at that pixel.

6. The method of claim 5, further comprising finding a depth of an object observed at each pixel, wherein the exclusion regions include a subset of pixels that image an object not within a threshold tolerance of a reference depth.

7. The method of claim 5, further comprising finding a surface temperature of an object observed at each pixel, wherein the exclusion regions include a subset of pixels that image an object not within a threshold tolerance of a reference surface temperature.

8. The method of claim 5, further comprising comparing a first matrix of pixels indicating an intensity of infrared light observed at a pixel while infrared light is being projected to that pixel and a second matrix of pixels indicating an intensity of infrared light observed at that pixel while infrared light is not being projected to that pixel, wherein the exclusion regions include that pixel if the intensity of infrared light observed at that pixel while infrared light is being projected to that pixel is within a threshold tolerance of the intensity of infrared light observed at that pixel while infrared light is not being projected to that pixel.

9. A data-holding subsystem holding instructions executable by a logic subsystem to:

receive a test matrix of pixels from a test image sensor;

identify one or more exclusion regions imaged by a subset of the test matrix of pixels;

receive a first-frame matrix of pixels from the primary image sensor; and

calculate an exposure setting for the primary image sensor using the first-frame matrix of pixels except those pixels imaging the one or more exclusion regions.

10. The data-holding subsystem of claim 9, where the exposure setting is a gain setting.

11. The data-holding subsystem of claim 9, where calculating an exposure setting includes constructing a histogram of the first-frame matrix of pixels except the pixels imaging the one or more exclusion regions.

12. The data-holding subsystem of claim 9, where the calculated exposure setting is applied to the primary sensor for subsequent matrices of pixels.

13. The data-holding subsystem of claim 9, where each pixel in the first-frame matrix includes visible light information indicating an intensity of visible light observed at that pixel.

14. The data-holding subsystem of claim 9, where each pixel in the test matrix includes infrared light information indicating an intensity of infrared light observed at that pixel.

15. The data-holding subsystem of claim 14, further holding instructions executable by the logic subsystem to:

find a depth of an object observed at each pixel, wherein the exclusion regions include a subset of pixels that image an object not within a threshold tolerance of a reference depth.

16. The data-holding subsystem of claim 14, further holding instructions executable by the logic subsystem to:

find a surface temperature of an object observed at each pixel, wherein the exclusion regions include a subset of pixels that image an object not within a threshold tolerance of a reference surface temperature.

17. The data-holding subsystem of claim 14, further holding instructions executable by the logic subsystem to:

compare a first matrix of pixels indicating an intensity of infrared light observed at a pixel while infrared light is being projected to that pixel and a second matrix of pixels indicating an intensity of infrared light observed at that pixel while infrared light is not being projected to that pixel, wherein the exclusion regions include that pixel if the intensity of infrared light observed at that pixel while infrared light is being projected to that pixel is within a threshold tolerance of the intensity of infrared light observed at that pixel while infrared light is not being projected to that pixel.

18. A method of calculating a gain setting for a visible light image sensor, the method comprising:

receiving a test matrix of pixels from an infrared image sensor;

identifying one or more exclusion regions imaged by a subset of the test matrix of pixels;

receiving a first-frame matrix of visible light pixels from the visible light image sensor; and

calculating a gain setting for the visible light image sensor using the first-frame matrix of visible light pixels except those pixels imaging the one or more exclusion regions.

19. The method of claim 18, further comprising applying the calculated gain setting to the primary sensor for subsequent matrices of pixels.

20. The method of claim 18, where calculating a gain setting includes constructing a histogram of the first-frame matrix of pixels except the pixels imaging the one or more exclusion regions.