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

• US 7,684,624 B2
• Filed: 03/03/2003
• Issued: 03/23/2010
• Est. Priority Date: 03/03/2003
• Status: Active Grant

• 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:
  US10/377,111
• Publication Number:
  US 20040175042A1
• Time in Patent Office: 2,577 Days
• Field of Search: 382/209, 345/156
• US Class Current: 382/209
• 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 capturing an image of a target area on which information is recorded comprising:

at least one imaging device capturing an image of said target area; 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 detect the presence of obstacles in the captured image, wherein during said processing said processor;

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

counts the number of pixels of the difference image having values suggestive of an obstacle and compares the number with a threshold value to detect the presence of an obstacle.

2. A system according to claim 1 wherein said processor 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 target area if an obstacle is detected.

4. A system according to claim 3 wherein said target area is a whiteboard on which information is recorded using a writing implement.

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

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

7. A camera-based system for capturing an image of a target area comprising:

a generally horizontally extending boom assembly, said boom assembly being positioned above a target area on which information is recorded;

at least one digital camera mounted on said boom assembly at a location spaced from the plane of said target area, said at least one digital camera being oriented so that the field of view thereof encompasses said target area; 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 the presence of an obstacle in the captured image, said processor conditioning said at least one digital camera to acquire another image of said target area if the presence of an obstacle in said captured image is detected, wherein during said processing, said processor;

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

counts the number of pixels of the difference image having values suggestive of an obstacle and compares the number with a threshold value to detect the presence of an obstacle in the captured image.

8. A camera-based system according to claim 7 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 target 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.

9. A camera-based system according to claim 8 wherein said boom assembly supports a pair of digital cameras.

10. A camera-based system according to claim 7 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.

11. A camera-based system according to claim 10 wherein said wall mount is releasably coupled to a wall plate secured to a wall surface.

12. A camera-based system according to claim 7 wherein 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 target area in the absence of an obstacle in the captured image.

13. A camera-based system according to claim 12 wherein said processor processes said high-resolution image to highlight writing on said target area.

14. A camera-based system according to claim 12 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.

15. A camera-based system according to claim 14 wherein said processor is a dedicated appliance.

16. A camera-based system according to claim 14 wherein said processor is a personal computer.

17. A camera-based system according to claim 7 wherein 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 target area in the absence of an obstacle in the captured image.

18. A camera-based system according to claim 17 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.

19. A camera-based system according to claim 18 wherein said processor is a dedicated appliance.

20. A camera-based system according to claim 18 wherein said processor is a personal computer.

21. A method of detecting the presence of an obstacle in front of a background surface on which information is to be recorded, in an image of said background surface captured by at least one imaging device, said method comprising the steps of:

receiving by a processor image data from the at least one imaging device;

comparing the image data with a reference image and computing a negative difference image by calculating, for corresponding pixels in said reference image and image data 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 image data; and

examining the negative difference image to determine if the negative difference image has pixels with values suggestive of an obstacle; and

conditioning said at least one digital camera to acquire another image if the presence of an obstacle in said captured image is detected.

22. The method of claim 21 wherein during said examining, the number of pixels having values suggestive of an obstacle is counted and compared with a threshold value.

23. A system for capturing an image of a target area on which information is recorded comprising:

at least one imaging device capturing an image of said target area; 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 detect the existence of an obstacle in the captured image, wherein during said processing said processor compares the captured image with a reference image to compute a negative difference image and examines the negative difference image to determine if pixels values thereof are suggestive of the existence of an obstacle, and 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 system according to claim 23 wherein said processor further processes said captured image if no obstacle is detected therein.

25. A system according to claim 24 wherein said processor conditions said at least one imaging device to capture another image of said target area if an obstacle is detected.

26. A system according to claim 25 wherein said target area is a whiteboard on which information is recorded using a writing implement.

27. A system according to claim 24 wherein during said further processing said processor displays said captured image.

28. A system according to claim 24 wherein during said further processing said processor posts said captured image to an Internet accessible site.

29. A camera-based system for capturing an image of a target area comprising:

a generally horizontally extending boom assembly, said boom assembly being positioned above a target area on which information is recorded;

at least one digital camera mounted on said boom assembly at a location spaced from the plane of said target area, said at least one digital camera being oriented so that the field of view thereof encompasses said target area; 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 the existence of an obstacle in the captured image, said processor conditioning said at least one digital camera to acquire another image of said target area if the existence of an obstacle in said captured image is detected, wherein during said processing, said processor compares the captured image with a reference image to compute a negative difference image and examines the negative difference image to determine if pixel values thereof are suggestive of the existence of an obstacle, and 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.

30. A camera-based system according to claim 29 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 target 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.

31. A camera-based system according to claim 30 wherein said boom assembly supports a pair of digital cameras.

32. A camera-based system according to claim 29 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.

33. A camera-based system according to claim 32 wherein said wall mount is releasably coupled to a wall plate secured to a wall surface.

34. A camera-based system according to claim 29 wherein said processor receives low resolution image data from said at least one digital camera and processes said low resolution image data to detect the existence of an obstacle in the captured image, said processor conditioning said at least one digital camera to acquire a high-resolution image of the target area in the absence of an obstacle in the captured image.

35. A camera-based system according to claim 34 wherein said processor processes said high-resolution image to highlight writing on said target area.

36. A camera-based system according to claim 34 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.

37. A camera-based system according to claim 36 wherein said processor is a dedicated appliance.

38. A camera-based system according to claim 36 wherein said processor is a personal computer.

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

40. A camera-based system according to claim 39 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.

41. A camera-based system according to claim 40 wherein said processor is a dedicated appliance.

42. A camera-based system according to claim 40 wherein said processor is a personal computer.

43. A method of detecting the presence of an obstacle in front of a background surface on which information is to be recorded, in an image of said background surface captured by at least one imaging device, said method comprising the steps of:

receiving by a processor image data from the at least one imaging device;

comparing the image data with a reference image and computing a negative difference image by calculating, for corresponding pixels in said reference image and image data 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 image data; and

examining the negative difference image to determine if the negative difference image has pixels with values suggestive of an obstacle; and

conditioning said at least one imaging device to acquire another image if the presence of an obstacle in said captured image is detected.

44. The method of claim 43 wherein during said examining, the number of pixels having values suggestive of an obstacle is counted and compared with a threshold value.