SOS & Help Gesture Detection: Emergency Hand-Raise Alert
Someone in trouble cannot always reach a phone or a panic button. A swimmer cramping mid-pool, a lone worker pinned in a yard at night, a customer collapsed in a vestibule with people passing on the other side of the glass – the universal signal in all of these is a raised arm waving for help, and on a wall of monitors it is invisible. SOS gesture detection turns that signal into an alert on the cameras already in place.
SOS gesture detection watches monitored zones for the raised-arm, repeated-wave pattern that people use to call for help, and raises an alarm with the clip attached the moment it fires. It is a posture-and-motion rule built on the same person-tracking stack as the rest of the library, and it runs on the edge appliance beside your existing cameras.
What the Rule Looks For
The rule builds on object detection and tracks each person’s upper-body pose over time. It fires on a sustained pattern: one or both arms raised above the head with a repeated waving motion, held long enough that an accident – stretching, hailing a taxi, fixing a hat – falls below the threshold. Duration, repetition count, and zone context are the three knobs, and each monitored zone carries its own settings.
Zone context is what makes the rule practical. A wave at a building entrance during business hours is life as usual; the same pattern inside a monitored pool after hours, or from an area where nobody should be waving at the camera at all, is a signal. Holding the pattern for the configured seconds is what separates a call for help from everything else, which is the core logic used throughout video analytics for turning raw motion into meaning.
How It Controls False Alarms
False alarms are managed in three layers. First, the sustained-pattern requirement filters casual movement – a greeting wave lasts one or two seconds; the rule asks for more. Second, activation is scheduled per zone, so enforcement only runs where and when a help signal is plausible. Third, every alert carries the clip, so an operator confirms in two seconds of footage before escalating. Sites that run the rule in review mode for the first week can retune the threshold from the recorded pattern distribution instead of guessing.
Camera health matters too: a rule that watches for gestures is only as good as its view, which is why sites pair it with camera displacement detection to catch a bumped or re-aimed camera before it silently blinds the safety net.
Linked Response When It Fires
The alert is the trigger for a chain you define: siren or strobe at the location, PA talk-down so the person knows help is coming, guard dispatch, or a message to a duty phone. What the person did right before the gesture often tells you how severe it is. A help wave that follows an alert from fall detection suggests someone fell and is conscious; one that follows loitering detection in a restricted area suggests a confrontation. The background on the fall side is in what fall detection actually measures, and group context comes from crowd gathering detection.
Where Sites Use It
Swimming pools are the clearest case: distress at the surface is exactly the raised-wave pattern, and poolside cameras cover it without wearables. Residential communities apply it to courtyards and gym rooms, and pair it with the resident-side view in elderly fall detection for older residents. Lone-worker sites – yards, workshops, fuel depots – use it where a worker may be out of earshot. Perimeter and after-hours zones combine it with intrusion detection: an intruder who signals for help is a different escalation than one who runs. Where someone walked away leaving a hazard behind, abandoned object detection covers the residue they left.
See how it runs on a real site in school security system.
Frequently Asked Questions
Will ordinary waving set it off?
No. The rule requires a sustained, repeated above-the-head pattern held for the configured duration. A greeting wave, a taxi hail, or adjusting a helmet does not persist long enough to fire. If a specific zone produces borderline cases, its duration threshold can be raised independently.
Can we define a custom gesture?
The library includes the standard help-gesture pattern. Custom gestures – a specific two-arm signal for industrial sites, for example – are possible as development work, which is quoted per scope rather than as a dated commitment. Where the gesture already exists in the library, the first demo takes about 7 days.
Does it work at night or in low light?
Yes, within the limits of the camera’s own image. The rule runs on the video stream, so a camera with adequate IR or lighting produces reliable results, and one that cannot see arms at night cannot protect that zone. We check each candidate camera angle during evaluation and flag any that fall short before deployment, not after the first missed signal.
How is it different from fall detection?
They are complementary, not competing. Fall detection answers “has someone collapsed”; SOS gesture detection answers “is someone upright but asking for help”. A person pinned under equipment, trapped behind a gate, or unable to move but not fallen is exactly the case the gesture rule catches that the fall rule does not. Sites that protect people usually run both.
Next Step
Send us the zones where a help signal must never be missed and a screenshot of each camera view. From the 198+ algorithm library this is configuration, not development – the first demo takes about 7 days where the detection already exists in the library. Start with a Starter Kit at USD 999, or tell us your scenario for a custom build quoted per site.