Summary
License plate recognition (LPR) requires special camera settings that are different from normal monitoring. The proper settings according to the monitoring environment can help you get clear license plate images and improve LPR performance. This article describes how to set up cameras for LPR, specifically in indoor parking lots.
Setting up Cameras
NOTE: Once the setup for LRP is complete, the video becomes very dark and may not
be suitable for monitoring objects other than license plates.
To set up the camera:
- Log in to the camera.
Select Settings > Video & Audio > Camera setup > Image preset mode.
NOTE: For ease of use, there are different image presets for different
purposes; it is important to choose the one that best suits the situation
in the camera.In this case, select Number plates as the Image preset mode.
NOTE: Number plates mode is used to improve the ability to identify the
license plate of a car in daytime and at night. However, for specialized
environments like indoor parking lots, this is not enough.
Additional Settings for Gain and Iris
- Typically, indoor parking lots have low light levels, so the car automatically turns on its headlights. The camera also increases the gain to almost maximum to increase the brightness of the footage.
- When a vehicle is detected, the license plate is over-saturated by the sudden brightening of the environment by the headlights. To avoid this, adjust the camera's gain and iris values for LPR so that the image brightness does not change too much when the amount of ambient light changes.
- For the P AI camera, select P-Iris to Manual to fix it and optimize the values while looking at the license plate. AGC should be set to Low to minimize the change.
- For the X AI camera, select Iris to Manual to fix it and optimize the Iris F-No values while looking at the license plate. AGC should be set to Low to minimize the change. AGC decreases the Level(Max Gain) by no more than 30 dB to prevent saturation.