Vehicle speed and vehicle queue length detection method based on machine vision

The invention relates to a vehicle speed and vehicle queue length detection method based on machine vision. The method is applied to a city crossroad. The method is characterized in that a detection area is arranged between a stop line of the city crossroad and a pedestrian crosswalk, and whether a vehicle exists is judged in the detection area; if the vehicle exists, the vehicle speed is calculated; when the vehicle speed on a lane is detected to be less than 2km/h, a queue length detection program is started; a plurality of movable virtual loops which are called telescopic windows for short are arranged along the corresponding lane, and when the sum of the number of nonzero pixels of the telescopic windows is detected to be larger than a certain threshold value and the difference of the number of the nonzero pixels in the telescopic windows and the number of all nonzero pixels in a previous time window is smaller than the certain threshold value, the lengths of the telescopic windows are correspondingly increased; finally, pixel values are changed into a practical length value through camera calibration.