---
lang: en
title: "People counting with re-identification across entrances"
url: https://nabrio.com/use-cases/people-counting
canonical: https://nabrio.com/use-cases/people-counting
updated: 2026-10-27
publisher: Nabrio Co., Ltd. (nabrio.com)
---

# People counting with re-identification across entrances

Simple door counters double-count people who come back or use several entrances. Nara counts people crossing lines at each entrance and uses person re-identification (ReID) to recognise the same visitor across cameras and devices, giving unique visitor counts and entries and exits by hour.

- Sectors: [Retail](https://nabrio.com/industries/retail.md), [Buildings and security](https://nabrio.com/industries/buildings-security.md), [More sectors](https://nabrio.com/industries/more-sectors.md)
- What it takes: Ready to configure. Works with Nara’s built-in models. You set up the zones, rules and outputs.
- Products: [Nara](https://nabrio.com/nara.md)

## The problem

Simple door counters double-count people who return or use several entrances.

## How it works

- **Input:** Entrance cameras
- **Process:** People detection, tracking and line crossing; ReID links the same person across cameras and devices
- **Action:** Unique visitor counts and entries and exits by hour, on dashboards and over MQTT

Nara detects and tracks people at each entrance and counts them as they cross the line in or out. Person re-identification recognises the same visitor across cameras, and multi-device sync shares that identity between Nara devices, so a returning visitor is not counted twice. Results feed dashboards and are published over MQTT to other systems.

## Variations

### Malls and stores

Unique visitor counts, entries and exits by hour, across every entrance.

### Events

Attendance per event space, combined with zone traffic and demographics for organisers and sponsors.

### Pets and pet carts

Pets are detected and counted at entrances for pet-friendly programmes. Pet carts can be trained in Reva.

## What you need

- IP cameras at each entrance
- One or more Nara devices; several can be paired into one site
- Optional: an MQTT broker for other systems

## Nara building blocks

- Multi-camera input
- People detection
- Tracker with line counting
- Person re-identification (ReID)
- Multi-device sync
- Dashboard
- MQTT publish

AI models: [People detection](https://nabrio.com/nara/ai-models.md), [Object tracking and analytics](https://nabrio.com/nara/ai-models.md), [Person re-identification (ReID)](https://nabrio.com/nara/ai-models.md)

## What it improves

- Accurate footfall
- Peak-hour staffing
- Tenant, marketing and event decisions

## Where it runs

- [120+ cameras and 20+ AI capabilities in one mall system](https://nabrio.com/customers/shopping-mall-ai-vision.md) (A shopping mall in Bangkok)

## Frequently asked questions

### Does re-identification use faces?

No. Person re-identification recognises the same person across cameras from their overall appearance, without faces.

### Can it cover a whole building?

Yes. Several Nara devices can be paired into one site and share ReID data, so a visitor keeps the same ID across devices. Our shopping mall deployment runs 120+ cameras on 4 edge devices in sync.

## Related use cases

- [Heatmaps and dwell time](https://nabrio.com/use-cases/footfall-heatmaps-and-dwell-time.md)
- [Visitor demographics](https://nabrio.com/use-cases/visitor-demographics.md)
- [Queue monitoring](https://nabrio.com/use-cases/queue-monitoring.md)

Talk to us about people counting: sales@nabrio.com. [Download Nara](https://nabrio.com/download.md).