System and method for capturing images of a target area on which information is recorded

• US 8,103,057 B2
• Filed: 02/22/2010
• Issued: 01/24/2012
• Est. Priority Date: 03/03/2003
• Status: Expired due to Term

• Current Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kroeker, Wallace, Ayinde, Olugbenga
• Primary Examiner(s): CHEN, WENPENG
• Application Number:
  US12/709,802
• Publication Number:
  US 20100149349A1
• Time in Patent Office: 701 Days
• Field of Search: 382/209, 382/103, 345/156
• US Class Current: 382/103
• 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: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60

Abstract

A system for capturing images of a target area on which information is recorded includes a boom assembly adapted to extend outwardly from a generally vertical surface. At least one digital camera is mounted on the boom assembly at a location spaced from the surface. The at least one digital camera is oriented so that the field of view thereof encompasses a target area on the surface. A controller is in communication with the at least one digital camera. The controller conditions the at least one digital camera to acquire an image of the target area. The image acquired by the at least one digital camera is conveyed to the controller and is processed to determine if an obstacle blocking the target area is in the captured image. If so, the captured image is not further processed and additional images are acquired until an image of the target area is captured without the obstacle therein.

Claims

1. A system for controlling image capture of a surface area on which information is recorded comprising:

at least one imaging device capturing an image of said surface area;

a moveable element located in a designated sub-region of said surface area and within the field of view of said at least one imaging device; and

a processor in communication with said at least one imaging device, said processor receiving image data from said at least one imaging device and processing said image data to determine if a visible change in a position of said moveable element within said sub-region has occurred.

2. A system according to claim 1 wherein said processor, upon determination of said visible change in position of said moveable element, processes said image data to detect the presence of one or more obstacles in the captured image and further processes said captured image if no obstacle is detected therein.

3. A system according to claim 2 wherein said processor conditions said at least one imaging device to capture another image of said surface area if an obstacle is detected.

4. A system according to claim 2 wherein during said further processing said processor displays said captured image.

5. A system according to claim 2 wherein during said further processing said processor posts said captured image to an Internet accessible site.

6. A system according to claim 2 wherein during said processing, upon determination of said visible change in position of said moveable element, said processor:

compares the captured image with a reference image and computes a difference image; and

examines the difference image to determine if the difference image has pixels with values suggestive of an obstacle.

7. A system according to claim 6 wherein during said examining, said processor counts the number of pixels having values suggestive of an obstacle and compares the number with a threshold value.

8. A system according to claim 7 wherein during said comparing a negative difference image is computed by said processor.

9. A system according to claim 8 wherein said negative difference image is computed by calculating, for corresponding pixels in said reference and captured images the pixel value:

(255−

|R_ij−

C_ij|)

where;

R_ij is the binary form of the pixel at the i^th row and j^th column in the reference image; and

C_ij is the binary form of the pixel at the i^th row and j^th column in the captured image.

10. A system according to claim 1 wherein said moveable element is slidable within said sub-region.

11. A system according to claim 10 wherein said surface area is a whiteboard on which information is recorded using a writing implement.

12. A system according to claim 10 wherein said moveable element is manually slidable within said sub-region.

13. A system according to claim 10 wherein said sub-region is adjacent a corner of said surface area.

14. A system according to claim 10 wherein said moveable element is slidable back and forth between two positions within said sub-region.

15. A system according to claim 14 wherein said moveable element is manually slidable between said two positions within said sub-region.

16. A system according to claim 15 wherein said sub-region is adjacent a corner of said surface area.

17. A camera-based system for controlling image capture of a surface area comprising:

a generally horizontally extending boom assembly, said boom assembly being positioned above a surface area on which information is recorded, a designated sub-region of said surface area further comprising an optical switch thereon;

at least one digital camera mounted on said boom assembly at a location spaced from the plane of said surface area, said at least one digital camera being oriented so that the field of view thereof encompasses said surface area including said optical switch; and

a processor in communication with said at least one digital camera, said processor receiving image data from said at least one digital camera and processing said image data to detect actuation of said optical switch within said sub-region, said processor conditioning said at least one digital camera to capture another image of said surface area when actuation of said optical switch is detected.

18. A camera-based system according to claim 17 wherein said boom assembly supports a plurality of digital cameras, each of said digital cameras having a field of view that encompasses a different section of said surface area, fields of view of adjacent digital cameras overlapping slightly, said processor stitching image data from said plurality of digital cameras to form said captured image.

19. A camera-based system according to claim 18 wherein said boom assembly supports a pair of digital cameras.

20. A camera-based system according to claim 17 wherein said processor processes said another captured image to detect the presence of an obstacle by:

comparing the another captured image with a reference image and computing a difference image; and

examining the difference image to determine if the difference image has pixels with values suggestive of an obstacle.

21. A camera-based system according to claim 20 wherein during said examining, said processor counts the number of pixels having values suggestive of an obstacle and compares the number with a threshold value.

22. A camera-based system according to claim 21 wherein during said comparing a negative difference image is computed by said processor.

23. A camera-based system according to claim 22 wherein said negative difference image is computed by calculating, for corresponding pixels in said reference and captured images the pixel value:

(255−

|R_ij−

C_ij|)

where;

R_ij is the binary form of the pixel at the i^th row and j^th column in the reference image; and

C_ij is the binary form of the pixel at the i^th row and j^th column in the captured image.

24. A camera-based system according to claim 20 wherein during processing of said another captured image, said processor receives low resolution image data from said at least one digital camera and processes said low resolution image data to detect the presence of an obstacle in the captured image, said processor conditioning said at least one digital camera to acquire a high-resolution image of the surface area in the absence of an obstacle in the captured image.

25. A camera-based system according to claim 24 wherein said processor processes said high-resolution image to highlight writing on said surface area.

26. A camera-based system according to claim 24 wherein said processor has Internet server capabilities and is coupled to a distributed computer network to allow said captured high-resolution image to be accessed by a user through an Internet browser.

27. A camera-based system according to claim 26 wherein said processor is a dedicated appliance.

28. A camera-based system according to claim 26 wherein said processor is a personal computer.

29. A camera-based system according to claim 20 wherein during processing of said another captured image, said processor receives high-resolution image data from said at least one digital camera and processes said high-resolution image data to detect the presence of an obstacle in the captured image, said processor further processing said high resolution image to highlight writing on said surface area in the absence of an obstacle in the captured image.

30. A camera-based system according to claim 29 wherein said processor has Internet server capabilities and is coupled to a distributed computer network to allow said captured high-resolution image to be accessed by a user through an Internet browser.

31. A camera-based system according to claim 30 wherein said processor is a dedicated appliance.

32. A camera-based system according to claim 30 wherein said processor is a personal computer.

33. A camera-based system according to claim 17 wherein said boom assembly includes a wall mount, a boom extending outwardly from said wall mount and a camera head on a distal end of said boom, said camera head supporting said at least one digital camera.

34. A camera-based system according to claim 33 wherein said wall mount is releasably coupled to a wall plate secured to a wall surface.

35. A camera-based system according to claim 17 wherein said optical switch is slidable within said sub-region.

36. A camera-based system according to claim 35 wherein said optical switch is manually slidable within said sub-region.

37. A camera-based system according to claim 35 where said sub-region is adjacent a corner of said surface area.

38. A method of detecting actuation of a switch element mounted on a designated sub-region of a background surface on which information is to be recorded, in a captured image of said background surface, said method comprising the steps of:

comparing the captured image with a previously captured image of said background surface; and

determining, based on the comparison, whether a visual change in the position of said switch element within said sub-region on said background surface has occurred.

39. The method of claim 38 wherein said determining comprises determining whether said switch element has been slid from one position to another position within said sub-region.

40. The method of claim 39 further comprising capturing another image of said background surface if said switch element has been slid from one position to another position within said sub-region and examining said another image to determine if pixels thereof have values suggestive of an obstacle.

41. The method according to claim 40 wherein during said examining the number of pixels having values suggestive of an obstacle is counted and compared with a threshold value.

42. A method of capturing and storing images of a background surface on which information is recorded, said method comprising the steps of:

capturing low resolution images of the background surface;

processing the low resolution images to determine if a switch element located on a designated sub-region of said background surface has been actuated within said sub-region; and

if the switch element has been actuated, further processing the low resolution images.

43. The method of claim 42 wherein during said processing, the low resolution images are processed to determine if said switch element has changed positions within said sub-region.

44. The method of claim 43 wherein during further processing, the low resolution images are processed to determine if an obstacle obscuring the background surface exits therein.

45. The method of claim 44 further comprising capturing high resolution images of said background surface if no obstacle is obscuring the background surface.

46. The method of claim 45 further comprising the step of displaying the captured high resolution images.

47. The method of claim 45 wherein during said processing for each captured low resolution image, if no obstacle is detected therein, the captured low resolution image is compared with a previously captured low resolution image to determine if a change in the recorded information has been made, and if a change in the recorded information has been made, storing said high resolution images.

48. The method of claim 45 further comprising the step of processing said high-resolution images to highlight information recorded on said background surface.

49. The method of claim 45 further comprising the step of posting the high-resolution images to an Internet accessible site.

50. A method of capturing and storing images of a background surface on which information is recorded, said method comprising the steps of:

capturing an image of the background surface;

processing the image to determine if a moveable switch located in a designated sub-region of said background surface has visibly changed positions within said sub-region; and

further processing the captured image if said moveable switch has visibly changed positions within said designated sub-region.

51. The method of claim 50 wherein said designated sub-region is adjacent a corner of said background surface.

52. The method of claim 51 wherein said visible change comprises movement of an element on said background surface from one position to another.

53. The method of claim 52 wherein said further processing comprises processing the captured image to determine if an obstacle obscuring the background surface exists therein and if not, highlighting information recorded on the background surface.

54. The method of claim 53 wherein images of the background surface are captured at intervals and wherein during the further processing, if no obstacle is detected in the captured image, the captured image is compared with a previously captured image to determine if a change in the recorded information has been made, and if a change in the recorded information has been made, further processing the image to highlight the recorded information.