METHOD AND APPARATUS FOR CAMERA PROJECTOR SYSTEM FOR ENABLING AN INTERACTIVE SURFACE

• US 20120176341A1
• Filed: 01/11/2012
• Published: 07/12/2012
• Est. Priority Date: 01/11/2011
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Dedeoglu, Goksel, Capps, Marshall Charles
• Application Number:
  US13/348,320
• Publication Number:
  US 20120176341A1
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

A method and apparatus for enabling an interactive surface. The method includes determining pixels of a depth image relating to an object at least one of touching or in close proximity to a related surface, differentiating between a small and a larger cluster of pixels, determining smaller cluster of pixels to be a level1 blob and the larger cluster of pixels to be a level2 blob and declaring the level1 blob an object touching the surface, and computing the coordinates of the level1 blob and repeating the process to enable the interactive surface.

Claims

1. A method of a digital processor for enabling an interactive surface, comprising:

determining pixels of a depth image relating to an object at least one of touching or in close proximity to a related surface;

differentiating between a small and a larger cluster of pixels;

determining smaller cluster of pixels to be a level1 blob and larger cluster of pixels to be a level2 blob and declaring the level1 blob an object touching the surface; and

computing the coordinates of the level1 blob and repeating the process to enable the interactive surface.

2. The method of claim 1, wherein computing the coordinates comprises computing centroid (x,y) of the pixels of the level1 blob.

3. The method of claim 1, wherein the step of determining smaller cluster of pixels to be a level1 blob comprises a step for determining pixels with a depth that is within the [d1, d2] depth interval, wherein d1 is marginally above the projection surface depth d0.

4. The method of claim 1 further comprising at least one of:

applying morphological operations to clean up the spurious pixels and to fill in holes; and

eliminating level1 blobs not connecting to a level 2 blob;

eliminating level1 blobs larger than their related level2 blob; and

utilizing intensity images for at least one of building and maintaining an appearance-based model of the scene, wherein deviating from the modeled value beyond a threshold the method determines the pixel to be a foreground pixel and re-labeling the level1 blobs overlapping with the same foreground blob and eliminates generating multiple level1 blobs from the same touch of an object;

eliminating a level1 blob when the depth range of the level1 blob is larger than a threshold; and

utilizing hidden projection patterns for depth sensing, wherein the structured light is at least one of a structured light, stereo vision, and unstructured light.

5. The method of claim 1, wherein the step of differentiating between a small and a larger cluster of pixels comprises applying a logical AND operation between level1 and level2 binary blob bitmasks to find out overlapping pixels.

6. The method of claim 1, wherein the step of determining larger cluster of pixels to be a level2 blob comprises a step for determining the pixels having depth within a threshold depth interval.

7. An interactive surface, comprising:

means for determining pixels of a depth image relating to an object at least one of touching or in close proximity to a related surface;

means for differentiating between a small and a larger cluster of pixels;

means for determining smaller cluster of pixels to be a level1 blob and the larger cluster of pixels to be a level2 blob and means for declaring the level1 blob an object touching the surface; and

means for computing the coordinates of the level1 blob and repeating the process to enable the interactive surface.

9. The interactive surface claim 7, wherein the means for determining smaller cluster of pixels to be a level1 blob comprises a means for determining pixels with a depth that is within the [d1, d2] depth interval, wherein d1 is marginally above the projection surface depth.

10. The interactive surface claim 7 further comprising at least one of:

means for applying morphological operations to clean up the spurious pixels and to fill in holes; and

means for eliminating level1 blobs not connecting to a level 2 blob;

means for eliminating level1 blobs larger than their related level2 blob; and

means for utilizing intensity images for at least one of building and means for maintaining an appearance-based model of the scene, wherein deviating from the modeled value beyond a threshold the method determines the pixel to be a foreground pixel and re-labeling the level1 blobs overlapping with the same foreground blob and eliminates generating multiple level1 blobs from the same touch of an object;

means for eliminating a level1 blob when the depth range of the level1 blob is larger than a threshold; and

means for utilizing hidden projection patterns for depth sensing, wherein the structured light is at least one of a structured light, stereo vision, and unstructured light.

11. The interactive surface claim 7, wherein the means for differentiating between a small and a larger cluster of pixels comprises means for applying a logical AND operation between level1 and level2 binary blob bitmasks to find out overlapping pixels.

12. The interactive surface claim 7, wherein the means for determining larger cluster of pixels to be a level2 blob comprises a means for determining the pixels having depth within a threshold depth interval.

8. The interactive surface 7, wherein the means for computing the coordinates comprises means for computing centroid (x,y) of the pixels of the level1 blob.

13. A non-transitory computer readable medium comprising computer instructions, when executed perform a method for enabling an interactive surface, the method comprising:

determining pixels of a depth image relating to an object at least one of touching or in close proximity to a related surface;

differentiating between a small and a larger cluster of pixels;

determining smaller cluster of pixels to be a level1 blob and the larger cluster of pixels to be a level2 blob and declaring the level1 blob an object touching the surface; and

computing the coordinates of the level1 blob and repeating the process to enable the interactive surface.

14. The non-transitory computer readable medium of claim 13, wherein computing the coordinates comprises computing centroid (x,y) of the pixels of the level1 blob.

15. The non-transitory computer readable medium of claim 13, wherein the step for determining smaller cluster of pixels to be a level1 blob comprises a step for determining pixels with a depth that is within the [d1, d2] depth interval, wherein d1 is marginally above the projection surface depth d0.

16. The non-transitory computer readable medium of claim 13 further comprising at least one of:

applying morphological operations to clean up the spurious pixels and to fill in holes; and

eliminating level1 blobs not connecting to a level 2 blob;

eliminating level1 blobs larger than their related level2 blob; and

utilizing intensity images for at least one of building and maintaining an appearance-based model of the scene, wherein deviating from the modeled value beyond a threshold the method determines the pixel to be a foreground pixel and re-labeling the level1 blobs overlapping with the same foreground blob and eliminates generating multiple level1 blobs from the same touch of an object;

eliminating a level1 blob when the depth range of the level1 blob is larger than a threshold; and

utilizing hidden projection patterns for depth sensing, wherein the structured light is at least one of a structured light, stereo vision, and unstructured light.

17. The non-transitory computer readable medium of claim 13, wherein the step of differentiating between a small and a larger cluster of pixels comprises applying a logical AND operation between level1 and level2 binary blob bitmasks to find out overlapping pixels.

18. The non-transitory computer readable medium of claim 13, wherein the step of determining larger cluster of pixels to be a level2 blob comprises a step for determining the pixels having depth within a threshold depth interval.