Video frequency car position detector and its detecting method

The present invention belongs to the urban indoor parking spaces Detection Field, wherein: the image sensor built-in memory and a CPU control circuit for controlling the image capture by CCD camera image read by the image acquisition control circuit, were then analyzed after the gradation value of the difference of the whole image of the software to calculate the background image and the measured image by subtracting the average of the mean and variance state improved by the CPU, then the difference between the average obtained from two the difference in variance to strike, to have more information and set minimum thresholds of the car, to determine the occupancy of parking spaces. The present invention has the indoor and outdoor general, easy installation and maintenance, the advantages of high detection accuracy.