Moving object detection apparatus and method

• US 5,134,472 A
• Filed: 02/07/1990
• Issued: 07/28/1992
• Est. Priority Date: 02/08/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Abe, Shozo
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Hsia, Sherrie
• Application Number:
  US07/476,323
• Time in Patent Office: 902 Days
• Field of Search: 358/105, 358/108, 358/126, 358/106, 358/22 PIP, 382/22
• US Class Current: 348/700
• CPC Class Codes: H04N 7/188 Capturing isolated or intermittent images triggered by the occurrence of a predetermined event, e.g. an object reaching a predetermined position signal generation from motion picture films H04N5/253

Abstract

A moving object detecting apparatus is disclosed and includes a TV camera for generating an image signal in accordance with a scene including a moving object and a fixed object. A CPU takes the difference, between the image signals generated by the TV camera at different times to generate a subtracted image signal. CPU then sets a pointing window over the subtracted image corresponding to the subtracted image signal which includes an image corresponding to the moving object. A CPU analyzes signals generated by the TV camera, within the pointing window, and detects an image area corresponding to the moving object.

Claims

1. An apparatus for detecting a moving image corresponding to a moving object within a fixed field of view of a monitoring device, the apparatus comprising:

input means for generating signals corresponding to a scene, corresponding to said fixed field of view, and including the moving object, at first and second times;

subtraction means for subtracting the signal generated by said input means at said first time from the signal generated by said input means at said second time to generate a subtracted image signal;

localization means for setting an image area covering a portion of said subtracted image signal; and

detection means for detecting movement of said moving object based on the subtracted image signal only in the image area set by said localization means.

2. The apparatus of claim 1, wherein said input means comprises line input means for generating multilevel signals along each scanning line;

said detection means comprising comparing means for comparing the multilevel signals with a threshold; and

further comprising means for generating a detection signal in response to a result of the comparison made by said comparing means.

3. The apparatus of claim 1, wherein said localization means sets the image area to cover the moving image.

4. The apparatus of claim 1, wherein the dimension of the image area is fixed.

5. The apparatus of claim 2, wherein said comparing means compares the multilevel signals with one threshold selected from a plurality of thresholds corresponding to a particular line.

6. An apparatus for detecting a moving image corresponding to a moving object within the field of view of a monitoring device, the apparatus comprising:

input means for generating signals corresponding to a scene, including the moving object, at first and second times;

correction means for correcting the signals in accordance with the distance between the moving object and said input means;

subtraction means for subtracting the signal generated by said input means at said first time and corrected by said correction means from the signal generated by said input means at said second time and corrected by said correction means to generate a subtracted image signal;

localization means for setting an image area covering at least a portion of said subtracted image signal;

detection means for detecting movement of said moving object based on the subtracted image signal in the image area set by said localization means.

7. The apparatus of claim 6, further comprising:

means for generating at least two position signals corresponding to at least two positions of the moving object;

means for calculating a correcting coefficient based on said at least two position signals.

8. An apparatus for detecting a moving image corresponding to a moving object, the apparatus comprising:

input means for generating signals corresponding to a scene including the moving object, at first and second times;

subtraction means for subtracting the signals generated by said input means at the first time from the signals generated by said input means at the second time to generate a subtracted image signal;

boundary detection means for generating an edge signal corresponding to a boundary between the object and its background; and

neglection means for deleting the edge signal from the subtracted image signal.

9. The apparatus of claim 8, further comprising:

evaluation means for comparing the subtracted image signal with the edge signal;

generating means for generating an image signal if the substracted image signal corresponds to an image signal and the edge signal corresponds to a non-image signal at the same position; and

selection means for selecting one signal from each of said neglection means and said generating mean;

wherein said moving object is detected based on said signal from said neglection means and said generating means.

10. The apparatus of claim 8, wherein said neglection means deletes the edge signal and neighborhood signals corresponding to the neighborhood of the boundary from the subtracted image signals.

11. The apparatus of claim 8, further comprising:

division means for dividing the signals generated by said input means into a plurality of groups of signals;

evaluation means for comparing the subtracted image signal with the edge signal within each group of signals;

logic means for performing a arithmetic logic operation between the subtracted image signal and the edge signal; and

selection means for selecting one signal from each of said neglection means and said logic means;

wherein said moving object is detected based on said signals from said neglection means and said logic means.

12. A method for detecting a moving image corresponding to a moving device within a fixed field of view of a monitoring device, comprising the steps:

generating signals corresponding to a scene corresponding to said fixed field of view, and including the moving object, at first and second times;

subtracting the signal generated by said generating step at the first time from the signal generated by said generating step at the second time to generate a subtracted image signal;

setting an image area covering a portion of the subtracted image signal;

detecting movement of the moving object based on the subtracted image signal only in the image area set by said setting step.

13. The method of claim 12, wherein said generating step comprises the step of generating multilevel signals along each scanning line;

said detecting step comprises the step of comparing the multi-level signals with a threshold; and

further comprising the step of generating a detection signal in response to a result of the comparison made by said comparing step.

14. The step of claim 12, wherein the dimension of the image area is fixed.

15. The step of claim 13, wherein said comparing step includes the step of comparing the multi-level signals with one threshold selected from a plurality of thresholds corresponding to a particular line.

16. A method of detecting a moving image corresponding to a moving object within the field of view of a monitoring device, comprising the steps:

generating signals corresponding to a scene, including the moving object, at first and second times;

correcting the signals in accordance with the distance between the moving object and said monitoring device;

subtracting the signal generated by said generating step at the first time and corrected by said correcting step from the signal generated by said generating step at the second time and corrected by said correcting step to generate a subtracted image signal;

setting an image area covering at least a portion of the subtracted image signal; and

detecting movement of the moving object based on the subtracted image signal in the image area set by said setting step.

17. The method of claim 16, further comprising the steps of:

generating at least two position signals corresponding to at least two positions of the moving object; and

calculating a correcting coefficient based on at least two positions data.

18. A method for detecting a moving image corresponding to a moving object, the method comprising the steps of:

generating a signal corresponding to a scene, including the moving object, at first and second times;

subtracting the signals generated by said generating step at the first time from the signals generated by the generating step at the second time to generate a subtracted image signal;

generating an edge signal corresponding to a boundary between an object including the moving object and a background;

deleting the edge signal from the subtracted image signal; and

detecting movement of the object based on the subtracted image signal deleted by said deleting step.

19. The method of claim 18, further comprising the steps of:

comparing the subtracted image signal with the edge signal;

generating an image signal if the subtracted image signal and the edge signal corresponds to a non-image signal at the same position; and

selecting one signal from each of said deleting step and said generating step;

wherein said moving object in detected based on the signal from said deleting step and/or said image signal generating step.

20. The method of claim 18, wherein said deleting step comprises the step of deleting the edge signal and neighborhood signals corresponding to the neighborhood of the boundary from the subtracted image signals.

21. An apparatus for detecting a moving image corresponding to a moving object within the field of view of a monitoring device, the apparatus comprising:

input means for generating signals corresponding to a scene, including the moving object, at first and second times;

correction means for correcting the signals in accordance with the distance between the moving object and said input means;

subtraction means for subtracting the signal generated by said input means at said first time and corrected by said correction means from the signal generated by said input means at said second time and corrected by said correction means to generate a subtracted image signal; and

detection means for detecting movement of said moving object in an image area within said field of view, based on the subtracted image signal.

22. The apparatus of claim 21, wherein said input means comprises line input means for generating multilevel signals along each of a plurality of scanning lines, and said detection means comprising comparing means for comparing the multilevel signals with a threshold and generating means for generating a detection signal in response to the comparison made by said comparing means.

23. The apparatus of claim 21, further including localization means for setting the image area to cover the moving image.

24. The apparatus of claim 21, wherein the dimension of the image area is fixed.

25. The apparatus of claim 22, wherein said comparing means compares the multilevel signals with one threshold selected from a plurality of thresholds, each corresponding to a particular line.

26. A method of detecting a moving image corresponding to a moving object within the field of view of a monitoring device, comprising the steps:

generating signals corresponding to a scene, including the moving object, at first and second times;

correcting the signals in accordance with the distance between the moving object and said monitoring device;

subtracting the signal generated by said generating step at said first time and corrected by said correcting step from the signal generated by said generating step at said second time and corrected by said correcting step to generate a subtracted image signal; and

detecting movement of said moving object in an image area within said field of view, based on the subtracted image signal.

27. The method of claim 26, wherein said generating step comprises the step of generating multilevel signals along each of a plurality of scanning lines, and said detecting step comprises the step of comparing the multilevel signals with a threshold and generating a detection signal in response to the comparison made by said comparing step.

28. The method of claim 26, wherein the dimension of the image area is fixed.

29. The method of claim 27, wherein said comparing step includes the step of comparing the multilevel signals with one threshold selected form a plurality of thresholds, each corresponding to a particular line.