Container Recognition
(Shipping Containers & Cargo)
Straight facts
This page explains how to deploy computer vision that reliably reads ISO 6346 container IDs, detects seals/placards/damage, and integrates with your yard/terminal systems—without hype.
📦 What it does
Detect a container on a truck/rail/yard stack → locate the ID zone → OCR the container number and size/type code → validate with ISO-6346 check digit → emit events (gate-in/out, tally, alerts) with images and confidence.
📋 Standards & fields we capture
🔢 ISO 6346 Container Number
Owner(3 letters) + Category(1 letter: U/J/Z) + Serial(6 digits) + Check digit(1)
We always validate the check digit to cut false reads
📐 Size/Type (4 chars)
e.g., 45G1 (40' HC GP)
BIC owner code lookup (optional)
🔒 Seal Presence & Number
Alphanumeric, length varies
⚠️ Hazard Placards & UN Numbers
IMDG/ADR icons + 4-digit UN code
🌡️ Reefer Panel Readouts
Setpoint, supply/return temps (when visible)
💥 Damage Cues
Dents/holes/rust/door misalignment (heuristic + ML)
🎯 Use cases
🚪 Gate-in/Gate-out OCR
Pair with ANPR/LPR and chassis ID
📊 Yard Tally & Inventory
Stack counts, location confirmation
🚂 Rail Portals & Quay Cranes
Side/top views
🏭 Warehouse Docks & Cross-docking
Check against ASN/booking
🛡️ Safety & Compliance
Hazard placard presence, seal check, door-open state
🏗️ System architecture (practical)
1. Trigger/Track
Loop/radar/LPR/vision tracker
2. Container Detector
Finds ID/placard/seal ROIs (multi-frame)
3. OCR
Robust fonts, grime, skew, reflections
4. Validation
ISO-6346 check digit + size/type grammar
5. Augment
ANPR, chassis ID, trailer USDOT
6. Events & APIs
JSON/REST/MQTT/CSV; optional EDI
7. Store
Cropped ROIs + full frames, retention policy
📷 Camera & optics that actually work
📐 Angles
- • Keep horizontal/vertical view angles ≤ 25–30°
- • Roll ≤ 5°
🎯 Pixel Density (OCR)
- • Character height ≥ 30–40 px
- • Prefer 50+ px for reliable reads
- • Seals/UN numbers often need more
⚡ Shutter
- • 1/1000–1/4000 s for moving trucks
- • Lock shutter and manage exposure via gain/IR
🎬 Frame Rate
- • 25–60 fps
- • Multi-frame voting improves read rate
💡 Illumination
- • Narrow-beam 850 nm IR (or white strobe)
- • Aimed at the ID area
- • WDR helps back-light
📹 Hardware
- • Global shutter preferred at high speed
- • Motorized varifocal (12–50 mm)
- • Use polarizer when glare is severe
🎥 Multi-camera Layout
Front (ANPR), side (container ID), rear/door (seal & door state), wide overview
📊 Performance metrics you should demand
📸 Capture Rate
Containers with a readable ID in frames
👁️ Read Rate
Correct IDs among captured, with/without check-digit validation
⚠️ UN Placard Detection
& seal-presence rate, seal OCR accuracy
⚡ Latency
Trigger → event, throughput (lanes/site), dropped frames
📈 Confidence Histograms
& threshold curves for tuning
⚠️ Common failure modes (and fixes)
💡 Headlight glare / retro-reflective washout
Fix: Strobe + shorter exposure + polarizer; aim IR narrowly
📐 Oblique views / occlusion by ladders/locks
Fix: Reposition camera; ensure one-side coverage where ID sits
🏭 Dirty/rusted panels / repaint
Fix: Enhance ROI; raise pixel density; use multi-frame voting and "unreadable" state
🔤 Font/spacing variations
Fix: Train with regional datasets; keep validators strict (check digit, grammar)
🚗 Fast drive-through
Fix: Pre-trigger (loop/radar), track across frames, aggregate votes
🔒 Data & privacy
💾 Storage Strategy
Store cropped ROIs + minimal full frames; configurable retention (e.g., 30–90 days)
🔐 Security Measures
Hash the container ID in indexes; encrypt in transit/at rest; role-based access
📋 ANPR Integration
When paired with ANPR, treat plate images as personal data (signage, access logs, purpose limitation)
🔗 Integration
📡 APIs
REST/MQTT/CSV webhooks with images, crops, confidence, timing
🏭 Systems
TOS/YMS/WMS/ERP; optional EDI exports (e.g., CODECO-like gate events, COARRI-style confirmations)
📊 Dashboards
Live lanes, read/capture rates, confidence histograms, device health
🚩 Red flags
❌ "Reads every container at any angle"
Without pixel-density or lighting plans
❌ No check-digit validation
Or owner/type grammar
❌ Single camera expected
To cover overview + ID + plate + seal
❌ No sample videos or lane-level KPIs
From pilots
🔗 GaugeSnap integration
🧠 Edge Vision Stack
Tuned for container ID + ISO-6346 check-digit validation, UN placard detection, seal presence/OCR, and reefer panel OCR (when visible)
🔗 ANPR Pairing
Truck plate ↔ container ID ↔ chassis, multi-frame voting, confidence scoring
🎯 Local & Special Cases
Fine-tune on regional fonts, repaint styles, or operator-specific seal formats
🔒 APIs & Privacy
REST/MQTT/CSV/EDI, hashed IDs, configurable retention, PDPA-ready logs
🚀 How to start (low-risk)
Send 30–60 s test videos per lane/view (day & night) showing the container side with the ID area, plus your target speeds/angles/distances. We'll return:
1. Camera/illumination/shutter plan
And pixel-density check
2. Baseline read-rate estimate
With check-digit validation and multi-frame voting
3. Integration outline
Events, APIs, retention/privacy