Study of System Construction for Automobile Traffic Detector using Video Camera

测量车辆宽度的方法有很多，S，但不停车就很难测量移动物体的长度。因此，需要一种非接触式的测量方法来测量车辆宽度。研究了利用便携式摄像机和PC机组成简单的系统结构，并探讨了利用傅里叶变换实现车辆宽度非接触测量的计算方法，认为图像上车辆的亮度与背景不同。通常的测量方法是统计车辆图像和背景图像之间的亮度差的像素数或边缘，但这种方法的精度不够高。我们将图像的空间频谱作为测量尺度，与车辆宽度相对应，并对亮度谱进行了频谱分析。然后，实现了车流中车辆宽度的测量。

There are many methods to measure the width of vehicles s, but it is difficult to measure the length of moving objects without stopping. So a noncontact measurement method is needed for the vehicle width measurement. This study deals with the simple system construction using a portable video camera and a personal computer, and surveys calculating method using Fourier Transformation to achieve noncontact measurement of vehicle width.We consider that the brightness of a vehicle on the image differs from background. The general measurement method is to count the pixels count or edge of difference in the brightness between a vehicle image and the background image, but the accuracy of this method is not high enough. We make a spatial frequency spectrum of the image for scale of measurement, which corresponds to vehicle width, and we reanalyze the frequency analysis of the brightness spectrum. Then, we achieved width measurement of vehicles in the traffic flow.