License Plate Recognition

License plate recognition (LPR), also called automatic license plate recognition (ALPR) or automatic number plate recognition (ANPR), is a computer vision technology that automatically reads vehicle license plates from camera video and converts them into searchable text.

How It Works

An LPR pipeline combines object detection and optical character recognition:

1. Plate detection. A neural network locates the plate region in each video frame.
2. Character segmentation. The plate image is cropped and normalized for reading.
3. Character recognition. A second model reads the alphanumeric string, often with region-specific models tuned for local plate formats and fonts.
4. Post-processing. The system applies checksum validation, multi-frame voting, and matches the plate against watchlists or allowlists.

Accurate systems read plates on vehicles moving up to 200 km/h at multiple cameras per site.

Why It Matters

License plate recognition turns every camera covering a road, gate, or parking lot into a structured data feed:

• Access control — barrier opens automatically for registered vehicles.
• Security — stolen or wanted vehicles are flagged the moment they enter a monitored area.
• Operations — truck dwell time in logistics yards, parking occupancy, toll enforcement.
• Revenue — paid parking and congestion charging without manual enforcement.

IncoreSoft's ALPR module supports plate formats from 100+ countries and integrates directly into Safe City deployments.

Use Cases

• Smart city traffic — red-light enforcement, lane monitoring, toll roads
• Law enforcement — stolen vehicle alerts, BOLO lists, forensic search
• Parking management — ticketless entry, occupancy analytics, billing
• Logistics and ports — truck identification, dwell time, yard management
• Corporate campuses — employee and visitor vehicle access control

Frequently Asked Questions

How accurate is license plate recognition?

Top engines read 95–99%+ of plates in controlled conditions. Accuracy drops with dirty plates, oblique angles, high beams, and heavy rain or snow. Proper camera placement and lens choice matter more than the AI model.

Does ALPR work at night?

Yes, when cameras have IR illumination or the ALPR engine is paired with infrared-sensitive lenses. Most dedicated ALPR cameras ship with built-in IR and shutter settings optimized for moving plates.

Can ALPR integrate with existing access control barriers?

Yes. IncoreSoft's ALPR exposes REST and relay outputs, so a confirmed match can trigger a gate, barrier, or bollard controller with no operator involvement.