Homography-based passive vehicle speed measuring

  • US 8,238,610 B2
  • Filed: 12/18/2009
  • Issued: 08/07/2012
  • Est. Priority Date: 12/18/2008
  • Status: Active Grant
  • ×
    • Pin Icon | RPX Insight
    • Pin
First Claim
Patent Images

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.

View all claims

    Thank you for your feedback