Estimating Vehicle Velocity Using Rectified Images

In this paper we propose a technique to estimate vehicles velocity, using rectified images that represent a top view of the highway. To rectify image sequences captured by uncalibrated cameras, this method automatically estimates two vanishing points using lines from the image plane. This approach requires two known lengths on the ground plane and can be applied to highways that are fairly straight near the surveillance camera. Once the background image is rectified it is possible to locate the stripes and boundaries of the highway lanes. This process may also be used to count vehicles, estimate their velocities and the mean velocity associated to each of the previously identified highway lanes.