Automatic monitoring and measuring vehicles by using image analysis

It is difficult to obtain stable roadway images when the camera shakes. In order to solve the problem, we present a two-point calibration method. Two symbol points in sequential frames are selected firstly, if the two points can be matched well in a sequence images, the sequential frames will be matched well. Then the frame difference method is used to segment moving vehicles. Since the moving vehicles signals are very weak, the signals are magnified by a dilation operation. Since the headmost moving vehicle is close to the backmost stationary vehicle on a roadway when traffic light is red, location of the backmost stationary vehicle can be determined by location of headmost moving vehicle. And the backmost stationary vehicle's computer image coordinate can be transformed to world coordinate by a camera model. As a result, the length of stationary vehicle queue can be calculated and estimated. And the ratio between stationary vehicle queue length and roadway length can be obtained. We can use the ratio to evaluate the congestion degree of the roadway.