Apparatus and method for controlling a camera using a video compression algorithm

• US 7,248,286 B2
• Filed: 08/22/2002
• Issued: 07/24/2007
• Est. Priority Date: 10/29/2001
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cho, Jae-soo
• Primary Examiner(s): Ometz; David
• Assistant Examiner(s): Tran; Nhan T.
• Application Number:
  US10/225,154
• Publication Number:
  US 20030081130A1
• Time in Patent Office: 1,797 Days
• Field of Search: 348/208.14
• US Class Current: 348/208.14
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G01S 3/7865 using correlation of the live video image with a stored image
• CPC Class Codes: G06T 7/215 Motion-based segmentation
• CPC Class Codes: G08B 13/19602 Image analysis to detect motion of the intruder, e.g. by frame subtraction
• CPC Class Codes: G08B 13/19608 Tracking movement of a target, e.g. by detecting an object predefined as a target, using target direction and or velocity to predict its new position
• CPC Class Codes: G08B 13/19689 Remote control of cameras, e.g. remote orientation or image zooming control for a PTZ camera
• CPC Class Codes: H04N 23/695 Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects
• CPC Class Codes: H04N 5/145 Movement estimation for video coding H04N19/51
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A method for controlling a camera using an image compression algorithm. A motion region and a motionless region are determined with respect to an input image based on a motion vector of a macro block which is for the generation of compressed data from the input image. A center value and a size of a moving object is estimated from the motion region. According to the center value and the size of the moving object, the camera is controlled to track and photograph the moving object. Accordingly, a central processing unit of the moving object tracking system is relieved of substantial processing load, and the processing speed of the system is improved.

Claims

1. A method for controlling a camera using information related to an image compression process, comprising the steps of:

determining a motion region and a motionless region of an input image photographed by the camera based on a motion vector of a macro block for generating a compressed data of the input image;

estimating a center value and a size of a moving object from the motion region; and

controlling the camera so that the camera tracks and photographs the moving object based on the estimated center value and size.

2. The method of claim 1, wherein the step of determining the motion region and the motionless region of the input image comprises the steps of:

calculating a moving distance of the macro block; and

determining the motion region and the motionless region according to a comparison between the calculated moving distance of the macro block and a threshold.

3. The method of claim 2, wherein the moving distance is calculated as the greater of an absolute change in a first direction and an absolute change in a second direction.

4. The method of claim 3, wherein the first direction is horizontal and the second direction is vertical.

5. The method of claim 2, wherein the moving distance is calculated as the square root of the sum of the square of a change in a first direction and the square of a change in a second direction.

6. The method of claim 5, wherein the first direction is horizontal and the second direction is vertical.

7. The method of claim 1, wherein the size of the moving object determined as an area of a square that surrounds a boundary of the motion region.

8. The method of claim 1, further comprising the steps of:

setting an area within a square as a tracking window for tracking the moving object,

estimating a moving location of the moving object based on preceding frames within the square, and

moving the tracking window according to the estimated moving location.

9. The method of claim 8, wherein the camera controlling step controls so that a photographing direction of the camera is shifted based on the estimated tracking window when a center value of the tracking window exists outside of a preset entire area of the input image.

10. The method of claim 1, wherein the camera controlling step controls a pan/tilt of the camera according to the estimated center value of the moving object.

11. The method of claim 10, wherein the pan/tilt controlling of the camera is performed when the center value of the moving object exists outside of the preset entire area of the input image.

12. The method of claim 1, wherein the camera controlling step controls a zoom-in/zoom-out of the camera according the estimated size of the moving object.

13. The method of claim 12, wherein the controlling step is performed such that the zoom-in is performed when the moving object exists inside of the preset entire area of the input image, while the zoom-out is performed when the moving object exists outside of the preset entire area of the input image.

14. The method of claim 1, wherein the controlling step performed such that the estimation of the center value of the moving object and the estimation of the size of the moving object are performed on a time-divisional basis.

15. An apparatus for controlling a camera using information related to an image compression process, comprising:

a photographing unit;

an image compression processing unit adapted to determine a motion region and a motionless region of an input image photographed by the photographing unit based on a motion vector of a macro block of the input image for generating compressed data representing the input image, and further adapted to estimate a center value and a size of a moving object from the motion region; and

a photographing control unit adapted to control the photographing unit so that the photographing unit tracks and photographs the moving object based on the estimated center value and size.

16. The apparatus of claim 15, wherein the image compression processing unit is further adapted to calculate a moving distance of the macro block and determine the motion region and the motionless region according to a comparison between the calculated moving distance of the macro block and a threshold.

17. The apparatus of claim 16, wherein the image compression processing unit is further adapted to calculate the moving distance as the greater of an absolute change in a first direction and an absolute change in a second direction.

18. The apparatus of claim 17, wherein the first direction is horizontal and the second direction is vertical.

19. The apparatus of claim 16, wherein the image compression processing unit is further adapted to calculate the moving distance as the square root of the sum of the square of a change in a first direction and the square of a change in a second direction.

20. The apparatus of claim 19, wherein the first direction is horizontal and the second direction is vertical.

21. The apparatus of claim 15, wherein the image compression processing unit is adapted to determine the size of the moving object as an area of a square that surrounds a boundary of the motion region.

22. The apparatus of claim 21, wherein the image compression processing unit is further adapted to set the area within the square as a tracking window for tracking the moving object, estimate a moving location of the moving object based on preceding frames within the square, and move the tracking window according to the estimated moving location.

23. The apparatus of claim 22, wherein the photographing control unit is adapted to control a direction of the photographing unit based on the estimated tracking window when a center value of the tracking window exists outside of a preset entire area of the input image.

24. The apparatus of claim 15, wherein the photographing control unit is adapted to control a pan/tilt of the photographing unit according to the estimated center value of the moving object.

25. The apparatus of claim 24, wherein the photographing control unit is further adapted to control the pan/tilt of the photographing unit when the center value of the moving object exists outside of a preset entire area of the input image.

26. The apparatus of claim 15, wherein the photographing control unit is adapted to control a zoom-in/zoom-out of the photographing unit according the estimated size of the moving object.

27. The apparatus of claim 26, wherein the photographing control unit is further adapted to control the photographing unit to zoom-in when the moving object exists inside of the preset entire area of the input image, and to zoom-out when the moving object exists outside of the preset entire area of the input image.

28. A computer readable medium having instructions stored thereon for controlling a camera using information related to an image compression process when the instructions are executed by a computer, comprising:

a first set of instructions, adapted to determine a motion region and a motionless region of an input image photographed by the camera based on a motion vector of a macro block for generating a compressed data of the input image;

a second set of instructions, adapted to estimate a center value and a size of a moving object from the motion region; and

a third set of instructions, adapted to control the camera so that the camera tracks and photographs the moving object based on the estimated center value and size.

29. The computer readable medium having instructions of claim 28, wherein the first set of instructions further comprises:

a fourth set of instructions, adapted to calculate a moving distance of the macro block; and

a fifth set of instructions, adapted to determine the motion region and the motionless region according to a comparison between the calculated moving distance of the macro block and a threshold.

30. The computer readable medium having instructions of claim 29, wherein the fourth set of instructions is adapted to calculate the moving distance as the greater of an absolute change in a first direction and an absolute change in a second direction.

31. The computer readable medium having instructions of claim 30, wherein the first direction is horizontal and the second direction is vertical.

32. The computer readable medium having instructions of claim 29, wherein the fourth set of instructions is adapted to calculate the moving distance as the square root of the sum of the square of a change in a first direction and the square of a change in a second direction.

33. The computer readable medium having instructions of claim 32, wherein the first direction is horizontal and the second direction is vertical.

34. The computer readable medium having instructions of claim 28, wherein the second set of instructions is adapted to estimate the size of the moving object as an area of a square that surrounds a boundary of the motion region.

35. The computer readable medium having instructions of claim 28, further comprising:

a sixth set of instructions, adapted to set an area within a square as a tracking window for tracking the moving object;

a seventh set of instructions, adapted to estimate a moving location of the moving object based on preceding frames within the square; and

an eighth set of instructions, adapted to move the tracking window according to the estimated moving location.

36. The computer readable medium having instructions of claim 35, wherein the third set of instructions is further adapted to control the camera to shift a photographing direction of the camera based on the estimated tracking window when a center value of the tracking window exists outside of a preset entire area of the input image.

37. The computer readable medium having instructions of claim 28, wherein the third set of instructions is adapted to control a pan/tilt of the camera according to the estimated center value of the moving object.

38. The computer readable medium having instructions of claim 37, wherein the third set of instructions is adapted to control the camera pan/tilt when the center value of the moving object exists outside of the preset entire area of the input image.

39. The computer readable medium having instructions of claim 28, wherein the third set of instructions is adapted to control the zoom of the camera according the estimated size of the moving object.

40. The computer readable medium having instructions of claim 39, wherein the third set of instructions is adapted to control the camera to zoom-in when the moving object exists inside of the preset entire area of the input image, and to zoom-out when the moving object exists outside of the preset entire area of the input image.