The installation of a license plate camera is crucial for the accuracy of license plate recognition. To achieve the best image quality and improve recognition success rates, multiple factors must be considered, such as image perspective, pixel resolution, and ambient lighting. This article will introduce important guidelines for installing license plate cameras.
📌 Table of Contents
■ Image Resolution and License Plate Pixel Requirements
■ Angle Adjustment
■ Ambient Lighting
■ Installation Location and Protective Measures
■ Network and Power Configuration
■ Conclusion
Image Resolution and License Plate Pixel Requirements
The horizontal width of a license plate image should be at least 80 pixels to ensure the camera can clearly capture plate details. High-resolution images improve recognition accuracy and prevent misidentification caused by blurry images.
Angle Adjustment
The camera’s installation angle affects image quality, so the viewing angle range must be controlled:
- Vertical Angle: The relative angle between the camera and the road surface should not exceed 30 degrees to ensure the license plate image is not too tilted to be recognized.
- Horizontal Angle: The relative angle between the camera’s shooting angle and the license plate should be kept within 30 degrees to avoid image distortion that could affect recognition results.
- License Plate Tilt: The tilt of the license plate relative to the horizontal line of the image should be maintained within ±7 degrees so the camera can accurately detect the characters on the plate.
Ambient Lighting
Insufficient light reduces image quality and affects the accuracy of license plate recognition, so you should choose an installation location with sufficient light. In addition:
- Use supplementary lights or infrared auxiliary lighting to improve night recognition.
- Avoid pointing the camera toward strong light sources to prevent glare that can impact license plate recognition.
- Consider using cameras with HDR (High Dynamic Range) technology to handle high-contrast environments, such as parking lots with strong light and shadows.
Installation Location and Protective Measures
To ensure the camera operates stably, choose a suitable installation location and provide protection:
- Installation Height: The installation height of the camera can be calculated using the Pythagorean theorem to determine the optimal height, tilt, and distance from the vehicle for the best license plate recognition. For a simpler calculation of the minimum distance (D) between the camera and the vehicle, you can use the formula: D=1.7∗H, where H is the installation height of the camera. For example, if the camera’s installation height is 3 meters, the minimum distance for effective license plate recognition is approximately 5.1 meters for the best viewing angle.
- Mounting Bracket: Use a shock-resistant and waterproof bracket to ensure stable camera operation.
- Dust and Water Protection: Choose a camera with an IP66 or higher protection rating to withstand harsh weather conditions.
Network and Power Configuration
- Use a stable network architecture, such as a TCP/IP network, to ensure real-time transmission of image data.
- Use an Uninterruptible Power Supply (UPS) to prevent sudden power outages from affecting license plate recognition functions.
Conclusion
Proper license plate camera installation not only enhances recognition effectiveness but also ensures long-term system stability. Following the installation guidelines above, including reasonable camera placement, angle adjustment, and lighting conditions—will effectively improve vehicle management efficiency, reduce recognition errors, and optimize the overall performance of intelligent traffic monitoring systems.