Documentation for Auto Intellect 5.5. Documentation for other versions of Intellect is available too.
To ensure the proper recognition of license plate numbers using the Auto-Intellect system, the angle between the camera axis and the direction of the vehicle movement is to be minimal.
The camera is to be installed on the optimal distance from the plate. If the camera is too far from the plate, the characters may not be large enough for recognizing them. In this case zoom-in until you reach the proper size. If the distance is too short it may happen that a part of the plate is over the camera's field of view.
For recognition it is necessary to make sure that frames with number plates fulfill the following characteristics:
- height of latin symbols is not less than 16 px, line-width is not less than 2px;
- height of non-latin symbols is not less than 20 px, line-width is not less than 2px;
- optimal character height is around 16-30 px;
- character size is not greater than 50 px in height;
- symbols should be sharp, not smeared, undistorted, not overexposed, evenly lighted;
- symbols should be visually differentiated;
- license plate number should be fully placed in the frame.
The following conditions may cause invalid results of LP recognition:
- low contrast;
- bad light conditions (shadow and strong light);
- high distortion;
- low spatial resolution;
- blurred image;