SELF CALIBRATION OF EXTRINSIC CAMERA PARAMETERS FOR A VEHICLE CAMERA
First Claim
1. A method for calibrating a camera that is moving relative to the ground, said method comprising:
- identifying at least two feature points in at least two camera images;
determining a camera translation and rotation between camera coordinates for different positions of the camera at a first position of the camera;
defining a ground plane in camera coordinates;
determining a height of the camera above the ground; and
identifying a rotation of the camera in vehicle coordinates.
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Abstract
A system and method for calibrating a camera on a vehicle as the vehicle is being driven. The method includes identifying at least two feature points in at least two camera images from a vehicle that has moved between taking the images. The method then determines a camera translation direction between two camera positions. Following this, the method determines a ground plane in camera coordinates based on the corresponding feature points from the images and the camera translation direction. The method then determines a height of the camera above the ground and a rotation of the camera in vehicle coordinates.
132 Citations
20 Claims
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1. A method for calibrating a camera that is moving relative to the ground, said method comprising:
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identifying at least two feature points in at least two camera images; determining a camera translation and rotation between camera coordinates for different positions of the camera at a first position of the camera; defining a ground plane in camera coordinates; determining a height of the camera above the ground; and identifying a rotation of the camera in vehicle coordinates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for calibrating a camera on a vehicle that is moving relative to the ground, said method comprising:
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identifying at least two feature points in at least two camera images; determining a camera translation and rotation between camera coordinates for different positions of the camera at a first position of the camera, wherein determining a camera translation and rotation includes identifying a location point of the camera in the at least two images relative to a normalized image plane, identifying a three-dimensional space using the camera location point for the two images of the camera and one of the feature points and determining a camera translation direction between the two images using the three-dimensional space; defining a ground plane in camera coordinates based on the at least two feature points and the camera translation direction, wherein defining the ground plane includes using the translation direction, the two points on the ground to determine a mean for the points on the ground, a dominant variation direction of the ground points and a ground norm direction; eliminating feature points that are not on the ground plane; determining a height of the camera above the ground by calculating an inner product between the mean of the featured points and the norm of the ground plane where the height of the camera is used to eliminate feature points that are not on the ground; and identifying a rotation of the camera in vehicle coordinates using a pitch down of the camera and a yaw of the camera. - View Dependent Claims (16, 17, 18, 19)
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20. A method for calibrating a camera on a vehicle that is moving relative to the ground, said method comprising:
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identifying at least two feature points in at least two camera images; determining a camera translation and rotation between camera coordinates for different positions of the camera at a first position of the camera, wherein determining a camera translation and rotation includes identifying a location point of the camera in the at least two images relative to a normalized image plane, identifying a three-dimensional space using the camera location point for the two images of the camera and one of the feature points and determining a camera translation direction between the two images using the three-dimensional space; defining a ground plane in camera coordinates based on the at least two feature points and the camera translation direction; determining a height of the camera above the ground by calculating an inner product between the mean of the featured points and the norm of the ground plane; and identifying a rotation of the camera in vehicle coordinates.
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Specification