How ANPR / LPR Technology Works

From infrared illumination to edge-AI character recognition — a complete plate read delivered in under 50 milliseconds, with no server required.

ANPR and LPR — Two Names, One Technology

Automatic Number Plate Recognition (ANPR) and License Plate Recognition (LPR) describe the same core technology. The name simply differs by region.

ANPR — Automatic Number Plate Recognition

The standard term used across the UK, Europe, Australia, and Asia. Refers to automated camera systems that read vehicle registration plates in real time and compare them against databases.

LPR — License Plate Recognition

The equivalent term used predominantly in North America. Identical technology and capabilities — the terminology reflects regional naming conventions for vehicle registration plates.

CatchSystems ANPR cameras support all major international plate formats — European, North American, and beyond.

Plate Read in Under 50 Milliseconds

Five distinct processes happen inside every CatchCAM camera each time a vehicle passes — so fast the driver never knows it happened.

01

Infrared Illumination

The camera emits infrared (IR) light — invisible to the human eye — that illuminates the retroreflective coating on the licence plate. This produces a consistently high-contrast image regardless of ambient lighting, day or night, without blinding drivers.

02

High-Speed Image Capture

A 2-megapixel sensor captures one or more frames of the passing vehicle. An optical IR filter removes ambient light noise, ensuring the plate characters are sharp and legible even at speeds up to 300 km/h.

03

Plate Localisation

The on-board AI model scans each captured frame and identifies the exact position and boundaries of the licence plate within the image — isolating it from the surrounding vehicle, road, and environment for character recognition.

04

Character Recognition

A deep-learning OCR model reads each character on the plate with 99% accuracy. The model automatically identifies the country format and plate layout — supporting all major international plate styles without manual configuration.

05

Real-Time Data Output

The recognised plate text, timestamp, GPS coordinates, camera ID, and confidence level are instantly transmitted to CatchKen or CatchKen Web for hitlist matching and logging — all before the vehicle has cleared the camera field of view.

On-Board AI — No Server Required

Traditional ANPR systems stream video to a central server for processing. This creates network latency, high bandwidth costs, and a single point of failure — unacceptable for law enforcement operations that must be reliable in the field.

CatchSystems CatchCAM cameras run the full AI recognition pipeline directly inside the camera hardware. The result is instant output, reduced bandwidth requirements, and a system that continues working even when the network doesn't.

See our cameras

Real-Time Results

No round-trip to a server. Results are available the instant the plate is captured — sub-50ms from frame to output.

Works Offline

No network required. Mobile patrol vehicles operate in areas with no coverage and still capture every plate — data syncs when connectivity returns.

Reduced Data Exposure

Video never leaves the camera. Only the resulting plate text is transmitted — significantly reducing data minimisation obligations under GDPR.

Lower Infrastructure Cost

No video processing servers to licence or maintain. Each camera is self-contained — scale the deployment without adding central processing capacity.

Visible and Invisible Infrared Illumination

Licence plates use retroreflective material that returns light directly to its source. IR illumination exploits this to produce consistently high-contrast plate images in any ambient light — bright sun, total darkness, rain, or fog.

Visible IR (Near-Infrared)

Produces a faint red glow visible at close range. Delivers maximum illumination intensity for high-speed capture — the preferred choice for open patrol use where camera visibility is not a concern. Used in the CatchCAM 2MP.

Invisible IR (850 nm / 940 nm)

Emits no visible light whatsoever. Required for covert operations where the camera must remain undetected — used in the CatchCAM Modular for undercover patrol vehicles and fixed covert surveillance positions.

Industry-Leading Accuracy

Independently validated performance figures, engineered for the most demanding real-world law enforcement conditions.

98% Capture Rate
99% Character Accuracy
300 km/h Max Speed
1–35m Reading Distance

Open Standards, Maximum Integration

CatchSystems cameras are built to open standards so they integrate seamlessly into any existing or future law enforcement infrastructure.

ONVIF Profile M

The open industry standard for IP-based physical security products. ONVIF Profile M certification ensures CatchCAM cameras integrate out-of-the-box with any ONVIF-compliant VMS, NVR, or third-party ANPR platform.

UTMC Protocol

The UK/EU Urban Traffic Management and Control standard. Native UTMC support provides instant compatibility with national traffic management infrastructure and police back-office systems across Europe.

ISO 9001 Certified

CatchSystems holds KIWA ISO 9001 certification — the international standard for quality management systems — guaranteeing consistent product quality and reliable processes at every stage of design, manufacturing, and support.

GDPR-Aware Design

On-board AI processing means sensitive video never leaves the camera. Only plate text data is transmitted — significantly reducing data minimisation obligations under GDPR and equivalent data protection legislation.

See the technology in action

Explore our product range to see how this technology is packaged, or book a live demonstration with our team.