Homography-based passive vehicle speed measuring
First Claim
1. An apparatus for passively measuring vehicle speed, comprising:
- at least one video camera for acquiring a plurality of images of a roadway upon which at least one moving vehicle travels upon, each of said plurality of images comprising a plurality of pixels;
a computer for processing pixel data associated with said plurality of pixels, said computer having code operable for processing said pixel data, wherein said processing said pixel data comprises;
performing background subtraction using an adaptive background subtraction model on said pixel data to identify a plurality of foreground pixels and to extract a plurality of blobs from said plurality of foreground pixels;
rectifying said plurality of blobs to form a plurality of rectified blobs using a homography matrix, said homography matrix obtained by comparing at least one known distance in said roadway with distances between said plurality of pixels and using a planar homography transform,identifying said moving vehicle from said plurality of rectified blobs, respective ones of said plurality of rectified blobs including vehicle data associated with said moving vehicle, andcomputing a speed of said moving vehicle from said vehicle data.
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Abstract
An apparatus for passively measuring vehicle speed includes at least one video camera for acquiring images of a roadway upon which at least one moving vehicle travels upon, each of the images comprising a plurality of pixels. A computer processes pixel data associated with the plurality of pixels, including using an adaptive background subtraction model to perform background subtraction on the pixel data to identify a plurality of foreground pixels, extracting a plurality of blobs from the foreground pixels, and rectifying the blobs to form a plurality of rectified blobs using a homography matrix. The homography matrix is obtained by comparing at least one known distance in the roadway with distances between the pixels. Using a planar homography transform, the moving vehicle is identified from the plurality of rectified blobs, wherein the respective ones of the plurality of rectified blobs include vehicle data associated with the moving vehicle. The speed of the moving vehicle is computed from the vehicle data.
44 Citations
16 Claims
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1. An apparatus for passively measuring vehicle speed, comprising:
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at least one video camera for acquiring a plurality of images of a roadway upon which at least one moving vehicle travels upon, each of said plurality of images comprising a plurality of pixels; a computer for processing pixel data associated with said plurality of pixels, said computer having code operable for processing said pixel data, wherein said processing said pixel data comprises; performing background subtraction using an adaptive background subtraction model on said pixel data to identify a plurality of foreground pixels and to extract a plurality of blobs from said plurality of foreground pixels; rectifying said plurality of blobs to form a plurality of rectified blobs using a homography matrix, said homography matrix obtained by comparing at least one known distance in said roadway with distances between said plurality of pixels and using a planar homography transform, identifying said moving vehicle from said plurality of rectified blobs, respective ones of said plurality of rectified blobs including vehicle data associated with said moving vehicle, and computing a speed of said moving vehicle from said vehicle data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for passively measuring vehicle speed, comprising:
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acquiring a plurality of images of a roadway upon which at least one moving vehicle travels upon, each of said images comprising a plurality of pixels; processing pixel data associated with said plurality of pixels, said computer having code operable for processing said pixel data, said processing comprising; performing background subtraction using an adaptive background subtraction model on said pixel data to identify a plurality of foreground pixels and to extract a plurality of blobs from said plurality of foreground pixels; rectifying said plurality of blobs to form a plurality of rectified blobs using a homography matrix, said homography matrix obtained by comparing at least one known distance in said roadway with distances between said plurality of pixels and using a planar homography transform, identifying at least said moving vehicle from said plurality of rectified blobs, respective ones of said plurality of rectified blobs including vehicle data associated with said moving vehicle, and computing a speed of said moving vehicle from said vehicle data. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification