System and Method for Camera Control in a Surveillance System

• US 20120212611A1
• Filed: 04/27/2012
• Published: 08/23/2012
• Est. Priority Date: 11/15/2010
• Status: Active Grant

• Current Assignee: Intergraph Technologies Company
• Original Assignee: Intergraph Technologies Company
• Inventors: Estes, Andrew D., Frederick, Johnny E.
• Granted Patent: US 8,624,709 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G08B 13/19641 Multiple cameras having overlapping views on a single scene
• CPC Class Codes: G08B 13/1968 Interfaces for setting up or customising the system
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A method and a system for calibrating a camera in a surveillance system. The method and system use a mathematical rotation between a first coordinate system and a second coordinate system in order to calibrate a camera with a map of an area. In some embodiments, the calibration can be used to control the camera and/or to display a view cone on the map.

Claims

1. A computer-implemented method for calibrating at least one camera, the system including at least one camera, the method comprising:

displaying a video feed from the at least one camera, the at least one camera having an orientation characterized by pan, zoom, and tilt coordinates;

displaying a map of an area, the map being characterized by geospatial coordinates;

allowing a user to select at least three pairs of points using at least one input device, a first point of the pair being selected in the map and a second point of the pair being selected from the video feed, the first point and the second point corresponding to the same geographic location;

converting, in a computer process, the at least three points selected in the map from geospatial coordinates into Cartesian coordinates defined by a first coordinate system;

converting, in a computer process, the at least three points selected in the video feed from pan, zoom, and tilt coordinates into Cartesian coordinates defined by a second coordinate system; and

determining, in a computer process, a mathematical rotation between the first coordinate system and the second coordinate system based upon the Cartesian coordinates for the at least three pairs of points.

2. A method according to claim 1, wherein the mathematical rotation is a matrix.

3. A method according to claim 1, further comprising:

displaying the location of the at least one camera on the map.

4. A method according to claim 1, wherein the geospatial coordinates are latitude, longitude, and altitude coordinates.

5. A method according to claim 1, wherein the input device is at least one of a mouse, a cursor, a crosshair, a touch screen, and a keyboard.

6. A method according to claim 1, further comprising:

allowing the user to select at least one point in the map using the at least one input device;

converting, in a computer process, the geospatial coordinates for the selected point into Cartesian coordinates defined by the first coordinate system;

applying, in a computer process, the rotation to the Cartesian coordinates for the selected point to determine Cartesian coordinates defined by the second coordinate system;

converting, in a computer process, the Cartesian coordinates defined by the second coordinate system into pan and tilt coordinates for the selected point; and

providing orientation instructions to the at least one camera based upon the pan and tilt coordinates for the selected point.

7. A method according to claim 1, further comprising:

receiving coordinates from a sensor for at least one target;

if the coordinates for the at least one target are not Cartesian coordinates defined by the first coordinate system, converting, in a computer process, the coordinates into Cartesian coordinates defined by the first coordinate system;

applying, in a computer process, the rotation to the Cartesian coordinates defined by the first Cartesian coordinate system to determine Cartesian coordinates defined by the second Cartesian coordinate system;

converting, in a computer process, the Cartesian coordinates defined by the second Cartesian coordinate system into pan and tilt coordinates; and

providing orientation instructions to the at least one camera based upon the pan and tilt coordinates.

8. A method according to claim 7, further comprising:

displaying the location of the at least one sensor on the map.

9. A method according to claim 7, further comprising:

displaying the location of the at least one target on the map.

10. A method according to claim 1, wherein the video feed has upper left, upper right, lower left, and lower right corners, and the method further comprising:

determining, in a computer process, effective pan and tilt angles for at least the lower left and lower right corners of the video feed based upon the pan, zoom, and tilt coordinates for the camera orientation;

converting, in a computer process, the effective pan and tilt angles for at least the lower left and lower right corners of the video feed into Cartesian coordinate defined by the second coordinate system;

applying, in a computer process, the rotation to the Cartesian coordinates defined by the second coordinate system to determine Cartesian coordinates defined by the first coordinate system for at least the lower left and lower right corners of the video feed;

determining, in a computer process, a view cone using the Cartesian coordinates defined by the first coordinate system for at least the lower left and lower right corners of the video feed;

determining, in a computer process, the view cone based upon the upper left and upper right corners of the video feed; and

displaying the view cone on the map.

11. A method according to claim 10, wherein, when the tilt coordinate for the camera is below the horizon, determining the view cone based upon the upper left and upper right corners of the video feed comprises:

determining, in a computer process, effective pan for the upper left and upper right corners of the video feed based upon the pan, zoom, and tilt coordinates for the camera orientation; and

converting, in a computer process, the effective pan and tilt angles for the upper left and upper right corners of the video feed into Cartesian coordinates defined by the second coordinate system;

applying, in a computer process, the mathematical rotation to the Cartesian coordinates to determine Cartesian coordinates defined by the first coordinate system for the upper left and upper right corners of the video feed; and

determining, in a computer process, the view cone based upon the Cartesian coordinates, defined by the first coordinate system, for the upper left, upper right, lower left and lower right corners.

12. A method according to claim 11, wherein the view cone is a polygon and the Cartesian coordinates, defined by the first coordinate system, for the upper left, upper right, lower left and lower right corners are the vertices of the polygon.

13. A method according to claim 10, wherein, when the tilt coordinate for the camera is above the horizon, determining the view cone based upon the upper left and upper right corners of the video feed comprises:

determining, in a computer process, effective tilt angles for the upper left and upper right corners of the video feed based upon the pan, zoom, and tilt coordinates for the camera.

determining, in a computer process, coordinates, defined by the first coordinate system, for the upper left and upper right corners of the video feed based upon a resolvable distance of the camera; and

determining, in a computer process, the view cone based upon the Cartesian coordinates, defined by the first coordinate system, for the upper left, upper right, lower left and lower right corners.

14. A method according to claim 13, wherein the view cone is a polygon and the Cartesian coordinates, defined by the first coordinate system, for the upper left, upper right, lower left and lower right corners are the vertices of the polygon.

15. Apparatus comprising at least one non-transitory computer readable medium encoded with instructions which when loaded on at least one computer, establish processes for calibrating at least one camera orientation characterized by pan, zoom, and tilt coordinates, the processes including:

allowing a user to select at least three pairs of points using at least one input device, a first point of the pair being selected in a map characterized by geospatial coordinates and a second point of the pair being selected from a video feed from the at least one camera, the first point and the second point corresponding to the same geographic location;

converting the at least three points selected in the map from geospatial coordinates into Cartesian coordinates defined by a first coordinate system;

converting the at least three points selected in the video feed from pan, zoom, and tilt coordinates into Cartesian coordinates defined by a second coordinate system; and

determining a mathematical rotation between the first coordinate system and the second coordinate system based upon the Cartesian coordinates for the at least three pairs of points.

16. An apparatus according to claim 15, wherein the instructions establish processes further including:

converting the geospatial coordinates for the selected point into Cartesian coordinates defined by the first coordinate system;

applying the rotation to the Cartesian coordinates for the selected point to determine Cartesian coordinates defined by the second coordinate system;

converting the Cartesian coordinates defined by the second coordinate system into pan and tilt coordinates for the selected point; and

providing orientation instructions to the at least one camera based upon the pan and tilt coordinates for the selected point.

17. An apparatus according to claim 15, wherein the instructions establish processes further including:

receiving coordinates from a sensor for at least one target;

if the coordinates for the at least one target are not Cartesian coordinates defined by the first coordinate system, converting the coordinates into Cartesian coordinates defined by the first coordinate system;

applying the rotation to the Cartesian coordinates defined by the first Cartesian coordinate system to determine Cartesian coordinates defined by the second Cartesian coordinate system;

converting the Cartesian coordinates defined by the second Cartesian coordinate system into pan and tilt coordinates; and

providing orientation instructions to the at least one camera based upon the pan and tilt coordinates.

18. An apparatus according to claim 15, wherein the instructions establish processes further including:

determining effective pan and tilt angles for at least the lower left and lower right corners of the video feed based upon the pan, zoom, and tilt coordinates for the camera orientation;

converting the effective pan and tilt angles for at least the lower left and lower right corners of the video feed into Cartesian coordinate defined by the second coordinate system;

applying the rotation to the Cartesian coordinates defined by the second coordinate system to determine Cartesian coordinates defined by the first coordinate system for at least the lower left and lower right corners of the video feed;

determining a view cone using the Cartesian coordinates defined by the first coordinate system for at least the lower left and lower right corners of the video feed;

determining the view cone based upon the upper left and upper right corners of the video feed; and

displaying the view cone on the map.

19. A calibrated system for controlling at least one camera, the system comprising:

a processor; and

a memory storing instructions executable by the processor to perform processes that include;

displaying a map of an area;

determining Cartesian coordinates for a point of interest, the Cartesian coordinates defined by a first coordinate system characterizing the map;

applying a mathematical rotation to the Cartesian coordinates for the point of interest to determine Cartesian coordinates defined by a second coordinate system, the second coordinate system characterizing a video feed from the at least one camera and the mathematical rotation providing a conversion between the first coordinate system and the second coordinate system;

converting the Cartesian coordinates defined by the second coordinate system into at least pan and tilt coordinates for the point of interest;

providing orientation instructions to the at least one camera based upon at least the pan and tilt coordinates for the point of interest; and

displaying the video feed from the at least one camera.

20. A system according to claim 19, wherein the processes further include:

allowing the user to select the point of interest in the map using at least one input device.

21. A system according to claim 19, wherein the point of interest is received from a sensor.