"The role of industrial cameras" What are the applications of industrial cameras in the transportation industry?

Vehicle identification in China is generally divided into three categories: large vehicles, small vehicles and locomotives. Industrial cameras can be used to binarize the license plate number image, identify and record the license plate number through feature matching, and through database comparison, each number can correspond to a certain vehicle type, which can be used to capture illegal vehicles, vehicle counting, vehicle type identification, origin and destination point investigation, travel time analysis, etc. License plate recognition technology can be roughly divided into three stages: pre-processing, which binarizes the image and removes noise; license plate positioning, which uses the connected component labeling method to find the connected components in the image and analyze them to determine the license plate position; character recognition, which after segmenting the characters, sets the size of the structural components according to the text size, and finally uses the morphological method to find the text features for comparison.

There are roughly four vehicle detection methods for industrial cameras. The principle of sample point detection is to select matrix-like sample points in a certain part of the lane. When a vehicle passes, the gray scale value of the sample point is different from the original road surface. If the statistical value of the subtraction between the two exceeds a certain threshold, it indicates the presence of the vehicle. Detection line detection is to lay out a virtual detection line composed of pixels in the direction of vertical or parallel traffic flow to facilitate the separation of the pixel depth of the road surface and the detection line. When a vehicle passes the detection line, the gray level value on the line is different from when no vehicle passes the road; if the difference in gray level value is greater than a certain threshold, it means that a vehicle has passed. These two detection methods are generally used in road sections where vehicles run alone. For complex road sections, how to lay out sample points or detection lines will become a difficulty. In addition to the two, full-screen detection is a vehicle detection method that uses the full screen for processing. This detection method can obtain more information, but the amount of data to be processed is also significantly increased. Nighttime vehicle detection is a detection method specifically designed for nighttime and darker illumination environments.

The recording of vehicle trajectories in continuous images is called tracking. Vehicle tracking methods under industrial camera applications mainly include pattern-based tracking, area-based tracking, and contour-based tracking.