Camera Placement
Use an elevated fixed view of the whole queue and exit path. Check lighting, scale, and occlusion on site.
Crowd Density Detection for Entry Queue Review
Crowd Density Detection brings a dense crowd accumulating at a gate or platform approach to an operator for review.
The Visible Condition
Describe What the Camera Can Show
The observable condition is a dense crowd accumulating at a gate or platform approach at a stadium entrance or transit approach. A frame can bring the scene to an operator. It cannot establish intent, cause, or the right response.
The São Paulo set moves from a dense turnstile band to a narrowing ramp and then a closed gate. Density is not uniform across each view. Stewards need to see where movement slows and whether people have a route out, rather than treating every queue as dangerous.
An authorized operator can enter a plain-language prompt such as “Alert when crowding builds at the stadium gate before kickoff.” StreamVLM™ evaluates sampled live frames from selected cameras against it. A match enters the IREX event flow.
Each detector has its own confidence threshold and alert cooldown. The team tests wording and settings on its cameras.
This prompt can be evaluated alongside the Crowd Management trained module. Compare their frame-rate needs and operational fit during a site-specific pilot.
Explore StreamVLM™Operational Fit
Plan the View and Review
Operator Decision
The reviewer should check flow and decide whether stewards should manage the queue. The prompt does not decide this automatically.
Likely False Matches
Check for an orderly scheduled queue or perspective that compresses spacing. Tune camera selection and alert settings during a pilot.
Illustrative Camera Frames
Look for Where the Flow Compresses
Synthetic frames illustrate possible matches. They are not real incidents, deployments, or accuracy evidence.
Turnstiles
Packed Turnstile Line
The band at the turnstiles is tightly packed while people farther back have more space.
Ramp
Compression on the Ramp
The queue moves loosely at the bottom but becomes dense where railings narrow near the gate.
Closed gate
Crowd at a Closed Gate
Supporters stand several deep against the gate and adjacent fence, with density falling away behind.
From Prompt to Action
How an Alert Becomes a Decision
- 01
Describe and Select
Use observable wording such as “Alert when crowding builds at the stadium gate before kickoff.” on cameras that show the complete relevant scene.
- 02
Review the Event
Open the match and surrounding footage. Compare with ordinary scenes such as an orderly scheduled queue or perspective that compresses spacing.
- 03
Apply the Site Procedure
Venue staff check movement, capacity, and on-site conditions. A frame alone cannot predict a crush.
Pilot Questions
Validate on Your Cameras
- Visibility
- Can the view consistently show a dense crowd accumulating at a gate or platform approach? Test representative lighting, weather, and occlusion.
- False Alerts
- Sample ordinary scenes, especially an orderly scheduled queue or perspective that compresses spacing, then tune prompt, threshold, and cooldown.
- Human Review
- Agree who checks a match and how to check flow and decide whether stewards should manage the queue. No universal accuracy figure is published for this prompt.
FAQ
What does crowd density detection report?
It reports a match to a described visible condition: a dense crowd accumulating at a gate or platform approach. An operator reviews footage before deciding what happened.
Can a match establish intent or liability?
No. A sampled frame cannot establish intent, authorization, responsibility, or cause. Staff check context and follow local procedure.
Can a single frame predict a crowd crush?
No. It shows visible density at that moment. Staff assess movement, capacity, gate status, and conditions on site.
How should we evaluate it?
Test representative cameras and ordinary scenes, including an orderly scheduled queue or perspective that compresses spacing. Agree on useful alerts and missed events. IREX does not publish a universal accuracy figure for this prompt.
Test Crowd Density Detection on Your Cameras
Choose representative views of a stadium entrance or transit approach. We can scope the prompt, alert settings, and review procedure for a pilot.