Automated camera handoff system for figure tracking in a multiple camera system

• US 6,359,647 B1
• Filed: 08/07/1998
• Issued: 03/19/2002
• Est. Priority Date: 08/07/1998
• Status: Expired due to Term

• Current Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Original Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Inventors: Murphy, Thomas, Sengupta, Soumitra, Lyons, Damian, Reese, Daniel
• Primary Examiner(s): Le, Vu
• Application Number:
  US09/131,243
• Time in Patent Office: 1,320 Days
• Field of Search: 348/143, 348/152, 348/153, 348/154, 348/159, 348/169, 382/103
• US Class Current: 348/154
• 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 13/19641 Multiple cameras having overlapping views on a single scene
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources
• 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

The invention provides for the automation of a multiple camera system based upon the location of a target object in a displayed camera image. The preferred system provides a nearly continuous display of a figure as the figure moves about throughout multiple cameras'"'"' potential fields of view. When the figure approaches the bounds of a selected camera'"'"'s field of view, the system determines which other camera'"'"'s potential field of view contains the figure, and adjusts that other camera'"'"'s actual field of view to contain the figure. When the figure is at the bounds of the selected camera'"'"'s field of view, the system automatically selects the other camera. The system also contains predictive location determination algorithms. By assessing the movement of the figure, the system selects and adjusts the next camera based upon the predicted subsequent location of the figure.

Claims

1. A camera handoff system comprising:

a location determinator that determines a location of a figure that is within an image from a first camera based on a location and an orientation of the first camera,

a field of view determinator that determines a field of view of a second camera based on a location and an orientation of the second camera, and

a controller, operably coupled to the location determinator and the field of view determinator, said controller selecting the second camera based at least partially upon whether the location of the figure is within the field of view of the second camera,

wherein the location determinator includes a predictor that determines a predicted location of the figure based on a one or more prior locations of the figure, the location of the figure being at least partially based on this predicted location.

2. The camera handoff system of claim 1, wherein the controller includes:

means for determining a target angle between the second camera and the location of the figure, and

means for orienting the second camera to said target angle.

3. The camera handoff system of claim 1, wherein the location determinator includes a figure tracking system.

4. The camera handoff system of claim 1, wherein the controller includes means for selecting and orienting the first camera in dependence upon an alarm signal from a sensor.

5. The camera handoff system of claim 1, wherein the selection of the second camera is also based on at least one of the following:

a proximity of a field of view of the first camera with the field of view of the second camera;

a likelihood of egress from the field of view of the first camera to the field of view of the second camera; and

obstructions between the field of view of the first camera and the field of view of the second camera.

6. The camera handoff system of claim 1, wherein the location determinator includes:

means for identifying an image location corresponding to the figure within the image from the first camera,

means for determining a line of sight between the first camera and the figure based on the image location, and

means for determining a distance between the first camera and the figure;

whereby the location of the figure corresponds to a point that is at the distance from the image location of the first camera along the line of sight.

7. The camera handoff system of claim 6, wherein the means for identifying the image location is a figure tracking system.

8. The camera handoff system of claim 7, wherein the controller includes means for selecting and orienting the first camera in dependence upon an alarm signal from a sensor.

9. The camera handoff system of claim 8, wherein the controller further includes:

means for determining a target angle between the second camera and the location of the figure, and

means for orienting the second camera to this target angle.

10. A security system for monitoring a secured area, comprising:

a plurality of cameras, each camera having a location and field of view within the secured area,

a monitor for viewing an image from a selected camera of the plurality of cameras, the selected camera having an orientation angle relative to the secured area,

means for identifying a portion of the image as a target, the portion of the image corresponding to an item within the selected camera'"'"'s field of view, the item having a location within the secured area, and the target having a location within the image,

means for determining the linear distance between the selected camera'"'"'s location and the item'"'"'s location,

means for determining the angular distance between the selected camera'"'"'s orientation and the item'"'"'s location, in dependence upon the location of the target within the image,

means for determining the item'"'"'s location in dependence upon the determined linear distance and angular distance, relative to the camera'"'"'s location,

means for selecting an other camera of the plurality of cameras in dependence upon the determined item'"'"'s location and the other camera'"'"'s field of view within the secured area.

11. The security system of claim 10, further including:

means for determining a target angle between the other camera and the location of the item, and

means for orienting the second camera to this target angle.

12. The camera handoff system of claim 10, wherein the means of identifying the portion of the image as the target includes a figure tracking system.

13. The camera handoff system of claim 10, further including means for selecting and orienting the selected camera in dependence upon an alarm signal from a sensor.

14. A method for selecting a second camera based on an image from a first camera, including the steps of:

identifying a target figure in the image from the first camera,

determining a target location of the target figure based on a location and an orientation of the first camera,

determining a field of view of the second camera based on a location and an orientation of the second camera,

selecting the second camera based upon whether the target location is within the field of view of the second camera,

identifying an image location corresponding to the target figure,

determining a line of sight between the first camera and the target figure based on the image location,

determining a distance between the first camera and the target figure, and

determining the target location as a point that is at the distance from the location of the first camera along the line of sight.

15. The method of claim 14, further including the steps of:

determining a target angle between the second camera and the target location, and

orienting the second camera to this target angle.

16. The method of claim 14, wherein the step of identifying the target figure includes the steps of:

identifying a portion of a first frame of the image as a target image,

determining characteristics of the target image, and

identifying the target figure as a portion of a second frame of the image that has the characteristics of the target image.

17. The method of claim 14, wherein the step of identifying the target figure includes the steps of:

identifying a portion of a first frame of the image as a target image,

determining characteristics of the target image, and

identifying the target figure as a portion of a second frame of the image that has the characteristics of the target image.

18. The method of claim 14, further including the steps of:

determining a target angle between the second camera and the location of the figure, and orienting the second camera to this target angle.