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To ensure the correct recognition of the carriage license plates, follow the requirements listed below.

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1. It is recommended to use the resolution of no more than 800x600, because using a resolution of more than 800x600 does not lead to the recognition quality improvement;
2. use black-and-white video cameras of high quallity quality because such cameras provides better quality of image at low light conditions;
3. the frames arrival rate should be not less than 24 fps;
4. The carriage motion speed must meet the camera operation speed. For a better recognition, it is necessary and it is enough to have 1-2 frames of a carriage number.
5. it should be possible to set a fixed exposure value (shutter) on video camera of 1/2000 s or less;
6. the video cameras should have high sensitivity (0,01 lx or more).

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1. The distance between the video camera and the carriage should be at least 1,5 meters (depends on the focal length of the camera lens), the optimal distance is 5-7 meters;

   Info
   title Note
   To simplify the setting, it is recommended to use the variofocal varifocal lenses. The focal length variation range should be selected in each case of the system installation. If you use the camera with an integrated lens with a focal length of 2.8 mm or less, then there may be strong geometric distortions on the image. As a result, the recognition quality may go down. To avoid this, it is necessary to use special removable lenses with an aspherical lens, which eliminate these distortions.

   
   

2. the cameras height for reading the side number is 3–3,5 meters, the cameras height for reading the chassis number is 1,5 meters;
3. the width of the carriage plate number in the image should be about 30-35% of the total image width, in most cases this means the width of the camera control zone is 3-5 meters;
4. the optical axis of video camera should be perpendicularly to plane of carriage plate;
5. the position of the carriage in the frame should be strictly horizontal;

6. the infrared sensor and the video camera should be located in the same vertical plane.

   Info
   title Note
   If the analog video camera is used, then to prevent the video signal fading on the transmission line, it is necessary that the distance from the video camera to the digitizing device does not exceed 30 meters.

   
   

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