< p> 　　 principle of license plate recognition system < / a > < p> License plate recognition PTZ camera captures license plates through light suppression and shielding, electronic shutter adjustment, wide dynamic functions, etc < p> Strong light shielding: Based on the low illumination color camera, the brightest part of the image is blocked through the function of the software. In traffic monitoring, the strong light of headlights can be blocked, so as to capture the license plate clearly. However, the biggest disadvantage of the camera is that the software can not distinguish clearly, and the brightest part of the image is not clearly defined. It is possible to block the license plate number, and can not deal with the capture of high-speed moving objects. At present, domestic cameras do more in strong light shielding, and the effects are different from each other. < p> Adjustable electronic shutter: for capturing objects moving at high speed (the vehicle speed on the highway is generally more than 70km / h), clear capturing can be realized by reducing the speed of the electronic shutter, which is generally adjusted manually. However, the biggest problem with this method is that the illumination is different during the day and at night. Two shutter speeds must be set to adapt to the monitoring during the day and at night. < p> Wide dynamic function: This is the best way to solve the impact of lights on capture. Wide dynamic was first proposed by Panasonic. When the background light is too bright, the ordinary camera can not solve the problem of light and dark image display. < p> As the most important means to determine the identity of vehicles in the field of intelligent transportation, license plate recognition technology has played a great role in realizing the intelligent management of traffic. License plate recognition technology has penetrated into all kinds of work.

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