Transformation between image and map coordinates
First Claim
1. A method of identifying map coordinates of a location within an image captured by a camera, the method comprising:
- obtaining, at a location server communicatively coupled to the camera, a first image captured by the camera;
selecting, at the location server, a single reference point appearing within the first image captured by the camera, the single reference point having known image coordinates and depicting a location with known two-dimensional map coordinates in an associated two-dimensional map;
computing, at the location server, at least one transformation parameter to transform two-dimensional camera coordinate locations for a camera frame of reference to two-dimensional map coordinate locations for the associated two-dimensional map, with the at least one transformation parameter including a rotation angle and a tilt angle of the camera relative to the single reference point, based on location data for the camera and the single reference point appearing within the image captured by the camera, with the location data expressed in terms of image coordinates and map coordinates and including a location and an elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point;
obtaining, at the location server, a second image captured by the camera;
detecting, within the second image, a target location to be tracked;
determining, at the location server, image coordinates of the target location; and
computing, at the location server, map coordinates of the target location based on the image coordinates of the target location and the at least one transformation parameter computed based on the location data for the camera and the single reference point appearing within the image captured by the camera, including the location and the elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point.
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Accused Products
Abstract
Systems and methods for transformations between image and map coordinates, such as those associated with a video surveillance system, are described herein. An example of a method described herein includes selecting a reference point within the image with known image coordinates and map coordinates, computing at least one transformation parameter with respect to a location and a height of the camera and the reference point, detecting a target location to be tracked within the image, determining image coordinates of the target location, and computing map coordinates of the target location based on the image coordinates of the target location and the at least one transformation parameter.
30 Citations
24 Claims
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1. A method of identifying map coordinates of a location within an image captured by a camera, the method comprising:
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obtaining, at a location server communicatively coupled to the camera, a first image captured by the camera; selecting, at the location server, a single reference point appearing within the first image captured by the camera, the single reference point having known image coordinates and depicting a location with known two-dimensional map coordinates in an associated two-dimensional map; computing, at the location server, at least one transformation parameter to transform two-dimensional camera coordinate locations for a camera frame of reference to two-dimensional map coordinate locations for the associated two-dimensional map, with the at least one transformation parameter including a rotation angle and a tilt angle of the camera relative to the single reference point, based on location data for the camera and the single reference point appearing within the image captured by the camera, with the location data expressed in terms of image coordinates and map coordinates and including a location and an elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point; obtaining, at the location server, a second image captured by the camera; detecting, within the second image, a target location to be tracked; determining, at the location server, image coordinates of the target location; and computing, at the location server, map coordinates of the target location based on the image coordinates of the target location and the at least one transformation parameter computed based on the location data for the camera and the single reference point appearing within the image captured by the camera, including the location and the elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A target coordinate translation system comprising:
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a camera configured to capture a first image and a second image, wherein the camera has a known location and elevation and a system of image coordinates is defined with respect to the first image and the second image; a calibration module communicatively coupled to the camera and configured to identify a single reference point appearing within the first image captured by the camera, the single reference point having known image coordinates and depicting a location with known two-dimensional map coordinates in an associated two-dimensional map, and to compute at least one transformation parameter to transform two-dimensional camera coordinate locations for a camera frame of reference to two-dimensional map coordinate locations for the associated two-dimensional map, the at least one transformation parameter including a rotation angle and a tilt angle of the camera relative to the single reference point, based on location data for the camera and the single reference point appearing within the image captured by the camera, with the location data expressed in terms of image coordinates and map coordinates and including the location and elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point; an object tracking module communicatively coupled to the camera and configured to select a target location within the second image and to identify image coordinates of the target location; and a coordinate transformation module communicatively coupled to the calibration module and the object tracking module and configured to compute map coordinates of the target location based on the image coordinates of the target location and the at least one transformation parameter computed based on the location data for the camera and the single reference point appearing within the image captured by the camera, including the location and the elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A system for identifying map coordinates corresponding to a location within a captured image, the system comprising:
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a camera configured to capture a first image and a second image, wherein the camera has a known location and elevation and a system of image coordinates is defined with respect to the first image and the second image; calibration means, communicatively coupled to the camera, for selecting a single reference point appearing within the first image captured by the camera, the single reference point having known image coordinates and depicting a location with known two-dimensional map coordinates in an associated two-dimensional map, and computing at least one transformation parameter to transform two-dimensional camera coordinate locations for a camera frame of reference to two-dimensional map coordinate locations for the associated two-dimensional map, with the at least one transformation parameter including a rotation angle and a tilt angle of the camera relative to the single reference point, based on location data for the camera and the single reference point appearing within the image captured by the camera, with the location data expressed in terms of image coordinates and map coordinates and including the location and elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point; tracking means, communicatively coupled to the camera, for detecting, within the second image, a target location and determining image coordinates of the target location; and mapping means, communicatively coupled to the calibration means and the tracking means, for computing map coordinates of the target location based on the image coordinates of the target location and the at least one transformation parameter computed based on the location data for the camera and the single reference point appearing within the image captured by the camera, including the location and the elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point. - View Dependent Claims (18, 19, 20, 21)
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22. A computer program product residing on a non-transitory processor-executable computer storage medium, the computer program product comprising processor-executable instructions configured to cause a processor to:
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identify information relating to a camera and a system of image coordinates relative to a first image and a second image captured by the camera; select a single reference point appearing within the first image captured by the camera, the single reference point having known image coordinates and depicting a location with known two-dimensional map coordinates in an associated two-dimensional map; compute at least one transformation parameter to transform two-dimensional camera coordinate locations for a camera frame of reference to two-dimensional map coordinate locations for the associated two-dimensional map, with the at least one transformation parameter including a rotation angle and a tilt angle of the camera relative to the single reference point, based on location data for the camera and the single reference point appearing within the image captured by the camera, with the location data expressed in terms of image coordinates and map coordinates and including location and elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point; detect, within the second image, a target location to be tracked; determine image coordinates of the target location; and compute map coordinates of the target location based on the image coordinates of the target location and the at least one transformation parameter computed based on the location data for the camera and the single reference point appearing within the image captured by the camera, including the location and the elevation of the camera in the map coordinates and the image coordinates and the known two-dimensional map coordinates of the single reference point. - View Dependent Claims (23, 24)
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Specification