Methods and Systems for Collaborative-Writing-Surface Image Formation

• US 20120062594A1
• Filed: 09/15/2010
• Published: 03/15/2012
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Campbell, Richard John
• Granted Patent: US 8,773,464 B2
• Time in Patent Office: Days
• US Class Current: 345/632
• CPC Class Codes: G06F 3/005 Input arrangements through a video camera
• 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
• CPC Class Codes: G06T 11/00 2D [Two Dimensional] image generation

Abstract

Aspects of the present invention relate to methods and systems for capturing, sharing and recording the information on a collaborative writing surface. According to a first aspect of the present invention, currently persistent collaborative-writing-surface content may be imaged during periods of occlusion by an occluder. According to a second aspect of the present invention, the occluder may be imaged as transparent allowing the visibility of the occluded currently persistent collaborative-writing-surface content. According to a third aspect of the present invention, the occluder may be imaged as a silhouette allowing visibility of the occluded currently persistent collaborative-writing-surface content.

Claims

1. A computer-implemented method for forming an image of a collaborative writing surface, said method comprising blending a prior result image with a current frame, wherein an occluded portion of said current frame is rendered based on a corresponding portion of said prior result image.

2. The method as described in claim 1 further comprising determining said occluded portion of said current frame.

3. The method as described in claim 2, wherein said determining said occluded portion of said current frame comprises tracking an occluder.

4. The method as described in claim 3, wherein said occluder is imaged as partially transparent in said image of said collaborative writing surface.

5. The method as described in claim 3, wherein said occluder is imaged as a silhouette in said image of said collaborative writing surface.

6. The method as described in claim 3, wherein said tracking comprises:

a) receiving a segmentation mask;

b) performing component filtering on said segmentation mask;

c) caching said filtered segmentation mask, thereby producing a filtered segmentation mask appearance over time;

d) estimating a global motion direction based on said appearance over time; and

e) determining a magnitude associated with said global motion direction.

7. The method as described in claim 1 further comprising:

a) determining an activity level associated with said collaborative writing surface; and

b) performing said blending only when said activity level indicates a change in the content on said collaborative writing surface.

8. The method as described in claim 1, wherein said current frame is a preprocessed version of a captured frame.

9. The method as described in claim 8, wherein said captured frame is corrected for perspective distortion and is cropped to a region-of-interest associated with said collaborative writing surface to form said current frame.

10. The method as described in claim 1, wherein said collaborative writing surface is a surface selected from the group consisting of flipchart, a whiteboard, a chalkboard and a piece of paper.

11. A collaboration system comprising:

a) a collaborative writing surface;

b) a capture device for acquiring a captured image corresponding of said collaborative writing surface; and

c) a virtual-transparency capture controller for forming an image of said collaborative writing surface, wherein said image is a blended version of a prior result image with a current frame related to said captured image, wherein an occluded portion of said current frame is rendered based on a corresponding portion of said prior result image.

12. The system as described in claim 11, wherein said collaborative writing surface is a surface selected from the group consisting of flipchart, a whiteboard, a chalkboard and a piece of paper.

13. The system as described in claim 11 further comprising an image rectifier for eliminating perspective distortion in said captured image to form said current frame.

14. The system as described in claim 11 further comprising an image demosaicer for demosaicing said captured image to form said current frame.

15. The system as described in claim 11, wherein said virtual-transparency capture controller comprises:

a) a foreground-object segmenter for identifying an occluder in said current frame; and

b) an occluder tracker for tracking said occluder.

16. The system as described in claim 15, wherein said occluder is imaged as partially transparent in said image of said collaborative writing surface.

17. The system as described in claim 15, wherein said occluder is imaged as a silhouette in said image of said collaborative writing surface.

18. The system as described in claim 15, wherein said occluder tracker comprises:

a) a segmentation-mask receiver for receiving a segmentation mask;

b) a component filter for performing component filtering on said segmentation mask;

c) a cache for caching said filtered segmentation mask, thereby producing a filtered segmentation mask appearance over time;

d) a motion estimator for estimating a global motion direction based on said appearance over time; and

e) a magnitude determiner for determining a magnitude associated with said global motion direction.

19. The system as described in claim 11, wherein said virtual-transparency capture control performs said blending only when an activity level indicates a change in the content on said collaborative writing surface.

20. The system as described in claim 11 further comprising an image enhancer for enhancing said image of said collaborative writing surface.