To ensure the recognition of the state license plates using the RIDR IntelliVision software module, it is necessary to install and configure the video cameras in such a way that the following requirements are met:

Camera specifications
  • Minimum video resolution 640*480, recommended resolution 720p or 1080p
  • Minimum frame rate 15 fps, recommended frame rate 25-30 fps
  • Autofocus, zoom is desired (for making small adjustments after setting up the recognizer)
  • Auto white balance/auto gain
  • IR for night mode with good contrast of license plate images
  • HDR/WDR
Video image
  • The video image should be clear, contrasting, without distortion, not blurry
  • License plate size should be 15-70% of the total image size
  • License plate should have no more than two rows of characters
Camera positioning
  • The video camera should be located at 0.6-2.4 meters above the ground
  • The angle between the bottom line of the license plate and the horizon line should be between 0 and 20 degrees
Vehicle speed
  • Slow to moderate (8-40 km/h)


The current recognition algorithm of the state license plates only works with the alphanumeric characters A-Z and 0-9. For countries that have their own letters on the license plate, they can be displayed as *.


Examples of correct and incorrect video images are given in Appendix 11. Examples of correct and incorrect video images for the LPR IntelliVision software module.


It is also recommended to see the manufacturer's specification.