AUGMENTED REALITY LIGHTING WITH DYNAMIC GEOMETRY

• US 20150262412A1
• Filed: 01/09/2015
• Published: 09/17/2015
• Est. Priority Date: 03/17/2014
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gruber, Lukas, Schmalstieg, Dieter, Ventura, Jonathan Daniel
• Application Number:
  US14/593,949
• Publication Number:
  US 20150262412A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06T 15/50 Lighting effects
• CPC Class Codes: G06T 19/006 Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00

Abstract

Methods for determination of AR lighting with dynamic geometry are disclosed. A camera pose for a first image comprising a plurality of pixels may be determined, where each pixel in the first image comprises a depth value and a color value. The first image may correspond to a portion of a 3D model. A second image may be obtained by projecting the portion of the 3D model into a camera field of view based on the camera pose. A composite image comprising a plurality of composite pixels may be obtained based, in part, on the first image and the second image, where each composite pixel in a subset of the plurality of composite pixels is obtained, based, in part, on a corresponding absolute difference between a depth value of a corresponding pixel in the first image and a depth value of a corresponding pixel in the second image.

Claims

1. A method comprising, at a computing device:

determining a pose of a camera for a first image, wherein the first image comprises a plurality of pixels, wherein each pixel in the first image comprises a depth value and a color value, and wherein the first image corresponds to a portion of a 3D model of a scene;

obtaining a second image based on the camera pose by projecting the portion of the 3D model into a camera Field Of View (FOV) of the camera; and

obtaining a composite image comprising a plurality of composite pixels based, in part, on the first image and the second image, wherein each composite pixel in a subset of the plurality of composite pixels is obtained, based, at least in part, on a corresponding absolute difference between a depth value of a corresponding pixel in the first image and a depth value of a corresponding pixel in the second image.

2. The method of claim 1, wherein obtaining each composite pixel in the subset comprises:

selecting, as each composite pixel in the subset, the corresponding pixel in the first image when the corresponding absolute difference is greater than a threshold;

or

selecting, as each composite pixel in the subset, the corresponding pixel in the second image when the corresponding absolute difference is less than the threshold.

3. The method of claim 1, wherein obtaining each composite pixel in the subset comprises:

determining, for each composite pixel in the subset;

a first count of pixels in a neighborhood around the corresponding pixel in the first image, wherein a neighborhood pixel is included in the first count when a corresponding absolute difference between a color value of the neighborhood pixel and a color value of the corresponding pixel in the first image is below a first threshold, and

a second count of pixels in the neighborhood, wherein a neighborhood pixel is included in the second count when a corresponding absolute difference between a depth value of the neighborhood pixel and a depth value of the corresponding pixel in the second image is below a second threshold; and

selecting, as each composite pixel in the subset, the corresponding pixel in the second image, when the second count is greater than a fraction of the first count.

4. The method of claim 3, wherein the corresponding pixel in the second image is selected when the second count is more than half the first count.

5. The method of claim 3, wherein the neighborhood is a polygon shaped region with a specified pixel distance around the corresponding pixel in the first image.

6. The method of claim 3, further comprising, at the computing device:

obtaining, for each composite pixel in the subset, a corresponding depth value as a median of depth values of pixels in the neighborhood, when the second count is not greater than a fraction of the first count.

7. The method of claim 1, further comprising:

updating the 3D model by adding new information in the first image to the 3D model.

8. The method of claim 1, further comprising, at the computing device:

determining at least one shadow map based on the 3D model, the composite image, and a virtual model, in part, by resolving occlusions;

(i) between one or more real world objects and one or more virtual objects in the FOV of the camera, wherein the virtual model comprises virtual objects, and (ii) between two or more of the real world objects;

computing a global illumination based, in part, on color values of pixels in the first image and the at least one shadow map;

determining a light estimation based, in part, on the global illumination and color values of pixels in the first image; and

obtaining a shading based, in part, on the light estimation and the global illumination.

9. The method of claim 8, wherein the global illumination is computed using Screen Space Directional Occlusion (SSDO) approximations and the method further comprises:

projecting the SSDO approximations into Spherical Harmonics (SH).

10. The method of claim 8, further comprising, at the computing device:

rendering an Augmented Reality (AR) image based on the shading and the color values of pixels in the first image.

11. A device comprising:

a camera comprising a depth sensor to obtain a first image, comprising a plurality of pixels, wherein each pixel in the first image comprises a depth value and a color value, and wherein the first image corresponds to a portion of a 3D model of a scene; and

a processor coupled to the camera, wherein the processor is configured to;

determine a camera pose for the first image;

obtain a second image based on the camera pose by projecting the portion of the 3D model into a Field Of View (FOV) of the camera; and

obtain a composite image comprising a plurality of composite pixels based, in part, on the first image and the second image, wherein each composite pixel in a subset of the plurality of composite pixels, is obtained, based, at least in part, on a corresponding absolute difference between a depth value of a corresponding pixel in the first image and a depth value of a corresponding pixel in the second image.

12. The device of claim 11, wherein, to obtain each composite pixel in the subset, the processor is configured to:

select, as each composite pixel in the subset, the corresponding pixel in the first image when the corresponding absolute difference is greater than a threshold;

or

select, as each composite pixel in the subset, the corresponding pixel in the second image when the corresponding absolute difference is less than the threshold.

13. The device of claim 11, wherein to obtain each composite pixel in the subset, the processor is configured to:

determine, for each composite pixel in the subset;

a first count of pixels in a neighborhood around the corresponding pixel in the first image, wherein a neighborhood pixel is included in the first count when a corresponding absolute difference between a color value of the neighborhood pixel and a color value of the corresponding pixel in the first image is below a first threshold, and

a second count of pixels in the neighborhood, wherein a neighborhood pixel is included in the second count when a corresponding absolute difference between a depth value of the neighborhood pixel and a depth value of the corresponding pixel in the second image is below a second threshold; and

select, as each composite pixel in the subset, the corresponding pixel in the second image, when the second count is greater than a fraction of the first count.

14. The device of claim 13, wherein the processor is configured to select the corresponding pixel in the second image when the second count is more than half the first count.

15. The device of claim 13, wherein the neighborhood is a polygon with a specified pixel distance around the corresponding pixel in the first image.

16. The device of claim 13, wherein the processor is further configured to:

obtain, for each composite pixel in the subset, a corresponding depth value as a median of depth values of pixels in the neighborhood, when the second count is not greater than a fraction of the first count.

17. The device of claim 11, wherein the processor is further configured to:

update the 3D model by adding new information in the live image to the 3D model.

18. The device of claim 11, wherein the processor is further configured to:

determine at least one shadow map based on the 3D model, the composite image, and a virtual model, in part, by resolving occlusions;

(i) between one or more real world objects and one or more virtual objects in the FOV of the camera, wherein the virtual model comprises virtual objects, and (ii) between two or more of the real world objects;

compute global illumination based, in part, on color values of pixels in the first image and the at least one shadow map;

determine light estimation based, in part, on the global illumination and the color values of pixels in the first image; and

obtain a shading based, in part, on the light estimation and the global illumination.

19. The device of claim 18, wherein the processor computes the global illumination using Screen Space Directional Occlusion (SSDO) approximations and wherein the processor is further configured to:

project the SSDO approximations into Spherical Harmonics (SH).

20. The device of claim 18, wherein the processor is further configured to:

render an Augmented Reality (AR) image based on the shading and the color values of pixels in the first image.

21. A device comprising:

imaging means a comprising a depth sensing means, the imaging means to obtain a live first image, comprising a plurality of pixels, wherein each pixel in the first image comprises a depth value and a color value, and wherein the first image corresponds to a portion of a 3D model of a scene; and

processing means coupled to the imaging means, wherein the processing means comprises;

means for determining an imaging means pose for the first image;

means for obtaining a second image based on the imaging means pose by projecting the portion of the 3D model into a Field Of View (FOV) of the imaging means; and

means for obtaining a composite image comprising a plurality of composite pixels based, in part, on the first image and the second image, wherein each composite pixel in a subset of the plurality of composite pixels, is obtained, based, at least in part, on a corresponding absolute difference between a depth value of a corresponding pixel in the first image and a depth value of a corresponding pixel in the second image.

22. The device of claim 21, wherein, means for obtaining each composite pixel in the subset comprises:

means for selecting, as each composite pixel in the subset, the corresponding pixel in the first image when the corresponding absolute difference is greater than a threshold;

or

means for selecting, as each composite pixel in the subset, the corresponding pixel in the second image when the corresponding absolute difference is less than the threshold.

23. The device of claim 21, wherein means for obtaining each composite pixel in the subset comprises:

means for determining, for each composite pixel in the subset;

a first count of pixels in a neighborhood around the corresponding pixel in the first image, wherein a neighborhood pixel is included in the first count when a corresponding absolute difference between a color value of the neighborhood pixel and a color value of the corresponding pixel in the first image is below a first threshold, and

a second count of pixels in the neighborhood, wherein a neighborhood pixel is included in the second count when a corresponding absolute difference between a depth value of the neighborhood pixel and a depth value of a corresponding pixel in the second image is below a second threshold; and

means for selecting, as each composite pixel in the subset, the corresponding pixel in the second image, when the second count is greater than a fraction of the first count.

24. The device of claim 23, wherein the means for selecting selects the corresponding pixel in the second image when the second count is more than half the first count.

25. The device of claim 23, further comprising:

means for obtaining, for each composite pixel in the subset, a corresponding depth value as a median of depth values of pixels in the neighborhood, when the second count is not greater than a fraction of the first count.

26. An article comprising:

a non-transitory computer readable medium comprising instructions that are executable by a processor to;

determine a camera pose for a live first image, wherein the first image comprises a plurality of pixels, wherein each pixel in the first image comprises a depth value and a color value, and wherein the first image corresponds to a portion of a 3D model of a scene;

obtain a second image based on the camera pose by projecting the portion of the 3D model into a Field Of View (FOV) of the camera; and

obtain a composite image comprising a plurality of composite pixels based, in part, on the first image and the second image, wherein each composite pixel in a subset of the plurality of composite pixels, is obtained, based, at least in part, on a corresponding absolute difference between a depth value of a corresponding pixel in the first image and a depth value of a corresponding pixel in the second image.

27. The article of claim 26, wherein the instructions are further executable by the processor to:

select, as each composite pixel in the subset, the corresponding pixel in the first image when the corresponding absolute difference is greater than a threshold;

or

select, as each composite pixel in the subset, the corresponding pixel in the second image when the corresponding absolute difference is less than the threshold.

28. The article of claim 26, wherein the instructions are further executable by the processor to:

determine, for each composite pixel in the subset;

a first count of pixels in a neighborhood around the corresponding pixel in the first image, wherein a neighborhood pixel is included in the first count when a corresponding absolute difference between a color value of the neighborhood pixel and a color value of the corresponding pixel in the first image is below a first threshold, and

a second count of pixels in the neighborhood, wherein a neighborhood pixel is included in the second count when a corresponding absolute difference between a depth value of the neighborhood pixel and a depth value of the corresponding pixel in the second image is below a second threshold; and

select, as each composite pixel in the subset, a corresponding pixel in the second image, when the second count is greater than a fraction of the first count.

29. The article of claim 28, wherein the corresponding pixel in the second image is selected when the second count is more than half the first count.

30. The article of claim 28, wherein the instructions are further executable by the processor to:

obtain, for each composite pixel in the subset, a corresponding depth value as a median of depth values of pixels in the neighborhood of the corresponding pixel in the first image, when the second count is not greater than a fraction of the first count.