Estimation of vehicle velocity and traffic intensity using rectified images

This paper presents an automatic method to estimate vehicle velocity and determine the number of vehicles per lane using rectified images. This approach requires the knowledge of two lengths on the ground plane and can be applied to highway scenarios that possess fairly straight lanes in areas near the camera. A scale factor is determined, in order to ascertain vehicle velocity in the sought units. This scale factor associates distances traveled on the image plane with distances on the ground plane and can be obtained by identifying the period and location of the striped highway lanes on the rectified background image. Once the previously referred lines are located it is then possible to locate the highway lane boundaries and, therefore, determine the mean vehicle velocity of each lane.