Datasheet
rev. 00025 · June 2026

Metrici LPR engine

Distributed license-plate recognition (LPR) engine

Features
Architecture
Distributed detection and recognition, free-flow or triggered
Recognition rate
More than 99.5%, using an appropriate infrared light source and camera positioning
Recognition speed
Less than 100 ms/plate at 200 pixels length
Plate number deviation
Up to ±30 degrees in any direction
Number of recognized plates in each frame
Unlimited
Trigger type
Over UDP from a Barix Barionet 50 LAN controller, from the Metrici LPR web interface, or from another Metrici engine (LPR, PPD, QR, etc.)
Chained trigger
Yes, to another Metrici engine (LPR, PPD, QR, etc.)
Companion stream
Yes
Vehicle tracking
Yes — direction of movement is determined by analyzing successive image frames
Detection window
Yes, user definable
Single plate mode
Yes
Number of barriers/gates controlled
Up to two for each connected camera, driven independently depending on the recognized plate number
GPS coordinates
Yes, if a GPS dongle is connected
Weight
Yes — the weighing scale should be connected to a Barix Barionet 50 equipped with special Metrici firmware
Speed
Yes, by using a Metrici Observer Radar
Data type for each recognized plate
Plate number, country code, recognition probability, moving direction of the car, first seen, last seen, location name, camera name, GPS latitude, GPS longitude, car picture, plate number picture, companion picture, weight, speed
Parallel processing
Adaptive multithreading, up to 8 threads for each connected camera
GPU acceleration
Yes — Intel, AMD or Nvidia supported
Data push
POST method over HTTP; two events generated: check_action and reporting
Plate number syntax check
Yes, for more than 57 countries, more than one at the same time
Supported countries
Albania, Argentina, Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Bahrain, Chile, Colombia, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Great Britain, Greece, Hong Kong, Hungary, India, Israel, Ireland, Italy, Jordan, Kuwait, Latvia, Lithuania, Luxembourg, Macedonia, Moldavia, Monaco, Montenegro, Netherlands, Norway, Peru, Philippines, Poland, Portugal, Qatar, Romania, Russia, Saudi Arabia, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Tanzania, Turkey, Ukraine, Zanzibar
System requirements
OS
Ubuntu 24.04 LTS MATE, Linux CentOS 7 (64-bit)
CPU
Intel i5, i7, i9 or Xeon; AMD Ryzen, Threadripper or Epyc
GPU
Intel, AMD or Nvidia; mandatory for more than 2 cameras/server
System memory
512 MB for each connected camera, but no less than 4 GB/server
GPU memory
At least 256 MB available for each connected camera
Storage
Up to 512 KB for each plate number stored in the buffer, depending on the camera resolution and image compression
Cameras/server
Up to 256 connected cameras on each server; unlimited number of servers
Camera type
IP; MJPEG, MxPEG, H.264 and H.265 video stream; HTTP or RTSP/RTP transport protocols
Supported camera producers
ACTi, Arecont, Avigilon, Axis, Bosch, Dahua, Diviotec, Hikvision, Mobotix, Novus, Pelco, Samsung, Sony, Uniview, Vivotek