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The image received from video cameras must be sharp, contrast and readable for the correct recognition of carriages and containers license plates.

Requirements for the video camera characteristics:

1. Use video cameras with high resolution (

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1. 720p is recommended)

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1. .
2. Frame rate is not less than 24

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1. FPS.
2. The container

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1. 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 container number.

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1. It should be possible to set a fixed exposure value (shutter) on a video camera of 1/2000 s

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1. or less

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1. .
2. High sensitivity of video cameras (0

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1. .01 lx and more).

The optical axis of video camera must

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be perpendicular to the plane of the license plate.

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To simplify the setting, it is recommended to use the varifocal lenses. The focal length variation range should be selected in each case of the system installation.

Image requirements:

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1. The position of a carriage or a container in the frame

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1. should be strictly horizontal

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1. .
2. Size of the license plate characters in the image must be from 20 to 40 pixels, i.e. from 4% of the image height

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1. .

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1. The geometric distortion by optics ("barrels" and "pincushions") should be reduced.

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When configuring video cameras, it is also required

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:

1. Focus camera exactly

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1. on the container or carriage license plate and disable the auto focus

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1. .
2. It is recommended to disable all

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1. video camera

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1. smart features. For

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1. example, the contrast enhancement mode

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1. .

The

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diagram of mounting video camera for providing the exact recognition of carriage license plates is shown in the following figure.

In the above image, you can see a sample application can be seen for the ACCR purposes. In many cases the container codes are damaged, therefore we suggest to capture capturing multiple images from different sides of the container and handle process them together as an image sequence. Three container cameras are recommended to reach To get the most precise reading results, it is recommended to use three container cameras. To provide the optimal conditions for taking an image, use two external white LED illuminator devices. With the help of an additional ANPR camera, the a truck, carrying the a container, can be identified.

To reduce consumption of the computer resources, use external triggering to capture images only if the container code and the license plate are in a good position.
The inductive loop (other triggering possibilities: laser sensor, microwave sensor, magnetic sensor or infrared barrier) serves as a sensor, which indicates the arrival of the vehicle.
As the vehicle stops at the “STOP” sign, all cameras identify the container code and the license plate of the truck.

The reference image received from the correctly mounted and setup video camera is shown in the following figure.

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