STOPPED OBJECT DETECTION

• US 20120162416A1
• Filed: 12/22/2010
• Published: 06/28/2012
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Pelco (Schneider Electric SE)
• Original Assignee: Pelco (Schneider Electric SE)
• Inventors: Aghdasi, Farzin, Su, Wei, Wang, Lei, Yang, Shu
• Granted Patent: US 9,154,747 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20081 Training; Learning
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 2207/30236 Traffic on road, railway or crossing
• CPC Class Codes: G06T 2207/30242 Counting objects in image
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: G06V 20/53 Recognition of crowd images, e.g. recognition of crowd congestion
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source
• CPC Class Codes: H04N 7/185 from a mobile camera, e.g. for remote control

Abstract

A video surveillance system includes: an input configured to receive indications of images each comprising a plurality of pixels; a memory; and a processing unit communicatively coupled to the input and the memory and configured to: analyze the indications of the images; compare the present image with a short-term background image stored in the memory; compare the present image with a long-term background image stored in the memory; provide an indication in response to an object in the present image being disposed in a first location in the present image, in a second location in, or absent from, the short-term background image, and in a third location in, or absent from, the long-term background image, where the first location is different from both the second location and the third location.

Claims

1. A video surveillance system comprising:

an input configured to receive indications of images each comprising a plurality of pixels;

a memory; and

a processing unit communicatively coupled to the input and the memory and configured to;

analyze the indications of the images;

compare the present image with a short-term background image stored in the memory;

compare the present image with a long-term background image stored in the memory;

provide an indication in response to an object in the present image being disposed in a first location in the present image, in a second location in, or absent from, the short-term background image, and in a third location in, or absent from, the long-term background image, wherein the first location is different from both the second location and the third location.

2. The system of claim 1 wherein the processing unit is further configured to:

update the short-team background image using the present image in response to lack of motion in images during a preceding short-term time threshold; and

update the long-term background image using the present image in response to lack of motion in images during a preceding long-term time threshold.

3. The system of claim 1 wherein the processing unit is configured to actuate an alarm in response to the indication only if the object is larger than a size threshold.

4. The system of claim 1 wherein the processing unit is configured to actuate an in response to the indication only if the object is within a size range.

6. The system of claim 1 wherein the system is a camera, the camera further comprising a video capture device configured to convert reflected light into the indications of the images, and wherein the input is communicatively coupled to the video capture device to receive the indications of the images from the video capture device.

7. The system of claim 1 further comprising a user interface communicatively coupled to the processing unit and configured to provide an alarm in response to the indication.

5. The system of 1 wherein the processing unit is configured to actuate an alarm in response to the indication only in response to the first location being different from each of the second location and the third location by at least a movement threshold.

8. A stopped object detection system comprising:

capturing means for capturing images of an area;

background means, communicatively coupled to the capturing means, for storing a short-term background image and a long-term background image;

motion detection means, communicatively coupled to the capturing means, for determining that an object is an in-motion object based on images captured by the capturing means; and

stopped object detection means, communicatively coupled to the motion detection means and the background means, for determining that a previously-moving object has stopped by comparing current-image information with the short-term background image and the long-term background image.

9. The system of claim 8 further comprising small-motion means, communicatively coupled to the motion detection means, for determining whether an amount of motion of the in-motion object is less than a threshold motion.

10. The system of claim 8 further comprising object size means, communicatively coupled to the motion detection means, for determining whether the in-motion object is of a size that is within a range of sizes of concern.

11. The system of claim 8 wherein the stopped object detection means are further for determining that the previously-moving object has stopped only if the previously-moving object is in a first location in the present image, in a second location in, or absent from, the short-term background image, and in a third location in, or absent from, the long-term background image, wherein the first location is different from both the second location and the third location.

12. The system of claim 11 wherein the stopped object detection means are further for determining whether the previously-moving object is within a zone of concern of the images.

13. The system of claim 12 wherein the stopped object detection means are further for triggering an alarm in response to the previously-moving object being stopped for longer than an alarm-triggering threshold within the zone of concern.

14. The system of claim 8 wherein the background means are further for updating the short-term background image with the previously-moving object.

15. The system of claim 14 wherein the background means are for updating the short-term background image with the previously-moving object after a threshold amount of time that depends upon a size of the previously-moving object.

16. A method for detecting a stopped object, the method comprising:

capturing images of an area using a camera;

producing a short-term background image and a long-term background image using the captured images;

determining that an object is an in-motion object based the captured images; and

producing a stopped-object indication in response to determining that a previously-moving object has stopped by comparing current-image information with the short-term background image and the long-term background image.

17. The method of claim 16 further comprising determining whether an amount of motion of the in-motion object is less than a threshold motion.

18. The method of claim 16 further comprising determining whether the in-motion object is of a size that is within a range of sizes of concern.

19. The method of claim 16 wherein determining that the previously-moving object has stopped comprises determining whether the previously-moving object is in a first location in the present image, in a second location in, or absent from, the short-term background image, and in a third location in, or absent from, the long-term background image, wherein the first location is different from both the second location and the third location.

20. The method of claim 19 further comprising determining whether the previously-moving object is within a zone of concern of the images.

21. The method of claim 20 further comprising actuating an alarm in response to the previously-moving object being stopped for longer than an alarm-triggering threshold within the zone of concern.

22. A computer program product residing on a non-transitory processor-readable medium and comprising instructions configured to cause a processor to:

produce a short-term background image and a long-term background image from images captured by a camera;

determine that an object is an in-motion object based on the captured images;

determine that a previously-moving object has stopped by comparing current-image information with the short-term background image and the long-term background image; and

produce a stopped-object indication in response to determining that the previously-moving object has stopped.

23. The computer program product of claim 22 further comprising instructions configured to cause the processor to determine whether an amount of motion of the in-motion object is less than a threshold motion.

24. The computer program product of claim 22 further comprising instructions configured to cause the processor to determine whether the in-motion object is of a size that is within a range of sizes of concern.

25. The computer program product of claim 22 wherein the instructions configured to cause the processor to determine that the previously-moving object has stopped comprise instructions configured to cause the processor to determine whether the previously-moving object is in a first location in the present image, in a second location in, or absent from, the short-term background image, and in a third location in, or absent from, the long-term background image, wherein the first location is different from both the second location and the third location.

26. The computer program product of claim 25 further comprising instructions configured to cause the processor to determine whether the previously-moving object is within a zone of concern of the images.

27. The computer program product of claim 26 further comprising instructions configured to cause the processor to actuate an alarm in response to the previously-moving object being stopped for longer than an alarm-triggering threshold within the zone of concern.