Display monitoring system for detecting and tracking an intruder in a monitor area

• US 5,243,418 A
• Filed: 11/27/1991
• Issued: 09/07/1993
• Est. Priority Date: 11/27/1990
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kuno, Yoshinori, Nakai, Hiroaki, Fukui, Kazuhiro
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US07/799,321
• Time in Patent Office: 650 Days
• Field of Search: 358/126, 358/125, 358/105, 358/108, 382/1
• US Class Current: 348/155
• 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 13/19691 Signalling events for better perception by user, e.g. indicating alarms by making display brighter, adding text, creating a sound
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A display monitoring system of the invention comprises an image pickup section for picking up an image including at least one of an object to be picked up and a background, a change detecting section for detecting an image changing area in the picked-up image, a tracking section for tracking the changing area, and a display monitoring system control section for controlling the tracking section, determining a tracking result, and performing predetermined processing. In addition, the system includes a display unit control section for outputting the data of the tracking area as data of a rectangular frame, and a display section for displaying the image picked up by the image pickup means together with the tracking area.

Claims

1. A display monitoring system comprising:

image pickup means for picking up an image including at least one of an object to be picked up and a background;

change detecting means for detecting an area in which a portion of the picked up changes,

said change detecting means including

reference image storage means for storing a background image, as a reference image, which corresponds to the background picked u by said image pickup means,

difference calculating means for obtaining differences between the reference image and the image including the object and the background, and outputting difference values,

binarizing means for binarizing difference values higher than a predetermined threshold value, and extracting the binarized values as a plurality of changing areas, and

labeling means for providing different labels for a plurality of blocks associated with each other as the changing areas, obtaining the area, position of center of gravity, and circumscribed rectangle of each of the blocks, and outputting measurement data;

tracking means for tracking the changing areas,

said tracking means including at least one tracking element having

tracking area setting means which moves upon movement of the block and sets a rectangular area including the rectangle as a tracking area, with the rectangle located in the center of the tracking area,

small moving direction detecting area setting means for setting a plurality of small areas in the tracking area, and

moving vector calculating means for calculating movement amounts of the changing areas in accordance with changes in parameter of each of the small areas; and

display monitoring system control means for controlling said tracking means, performing determination of a tracking result, and performing predetermined processing by using the output from said labeling means,

said display monitoring system control means including

tracking section control means for controlling said tracking means and

tracking result processing means for determining on the basis of the tracking result from said tracking means whether the changing areas originate from an intruding object, and performing predetermined processing.

2. A system according to claim 1, further comprising display unit control means for outputting data of the tracking area as data of a rectangular frame, and

display means for displaying the image picked up by said image pickup means together with the tracking area.

3. A system according to claim 1, wherein said change detecting means includes means for detecting the changing area on the basis of a difference between at least two images with respect to time.

4. A system according to claim 1, wherein said reference image storage means includes means for updating the reference image after the lapse of a predetermined period of time.

5. A system according to claim 1, wherein said tracking means includes a plurality of tracking elements, and said tracking result processing means includes

candidate extracting means for obtaining a virtual association strength between said tracking elements for tracking the changing areas, and extracting each of groups of said tracking elements whose association strengths are higher than a predetermined value as candidates for moving objects, and

result interpreting means for interpreting extraction results obtained by said candidate extracting means and forming moving paths of the moving object candidates.

6. A system according to claim 5, further comprising second display means for displaying interpretations of the tracking results by said result interpreting means.

7. A display monitoring system comprising:

image pickup means for picking up an image including at least one of an object to be picked up and a background;

change detecting means for detecting an area in which a portion of the picked-up image changes,

said change detecting means including

reference image storage means for storing a background image, as a reference image, which corresponds to the background picked up by said image pickup means,

difference calculating means for obtaining differences between the reference image and the image including the object and the background, and outputting difference values,

binarizing means for binarizing difference values higher than a predetermined threshold value, and extracting the binarized values as a plurality of changing areas, and

labeling means for providing different labels for a plurality of blocks associated with each other as the changing areas, obtaining the area, position of center of gravity, and circumscribed rectangle of each of the blocks, and outputting measurement data;

tracking means for tracking the changing areas,

said tracking means including at least one tracking element having

tracking area setting means which moves upon movement of the block and sets a rectangular area including the rectangle as a tracking area, with the rectangle located in the center of the tracking area,

small moving direction detecting area setting means for setting a plurality of small areas in the tracking area, and

moving vector calculating means for calculating movement amounts of the changing areas in accordance with changes in parameter of each of the small areas;

display monitoring system control means for controlling said tracking means, performing determination of a tracking result, and performing predetermined processing by using the output from said labeling means,

said display monitoring system control means including

tracking section control means for controlling said tracking means,

candidate extracting means for obtaining a virtual association strength between said tracking elements for tracking the changing areas, and extracting each of groups of said tracking elements whose association strengths are higher than a predetermined value as candidates for moving objects, and

result interpreting means for interpreting extraction results obtained by said candidate extracting means and forming moving paths of the moving object candidates;

display unit control means for outputting data of the tracking area as data of a rectangular frame;

first display means for displaying the image picked up by said image pickup means together with the tracking area; and

second display means for displaying an interpretation of the tracking result obtained by said result interpreting means.

8. A display monitoring system comprising:

change detecting means for detecting image changing areas in a picked-up image;

tracking means having at least two tracking elements for tracking the changing areas detected by said change detecting means;

candidate extracting means for obtaining a virtual association strength between said tracking elements for tracking the changing areas, and extracting each of groups of said tracking elements whose association strengths are higher than a predetermined value as candidates for moving objects; and

result interpreting means for interpreting extraction results obtained by said candidate extracting means and forming moving paths of the moving object candidates.

9. A system according to claim 8, wherein said candidate extracting means includes means for calculating a virtual association strength between said tracking elements by using an estimation function assuming a large value when moving paths of said tracking element are similar to each other.

10. A system according to claim 8, wherein said candidate extracting means includes means for extracting groups of said tracking elements, as moving object candidates, which have association strengths higher than a predetermined value at all time points when the changing areas are tracked by said tracking means.

11. A system according to claim 8, further comprising means for causing said candidate extracting means to form a candidate list, constituted by tracking element groups as moving object candidates, at each time point, and causing said result interpreting means to convert the candidate list string into a data string representing moving paths of moving objects.

12. A system according to claim 8, further comprising knowledge providing means for providing knowledge requested by said candidate extracting means and said result interpreting means.

13. A system according to claim 8, wherein said result interpreting means includes means for associating candidates for moving objects which can be determined to be identical from candidate extraction results obtained by said candidate extracting means at a plurality of consecutive time points.