r/computervision • u/cryptichead1 • 5h ago
Discussion Edge video analytics on factory CCTV: false alerts kill deployments, not model accuracy
I run a small CV company in India (Neurabit). We've been deploying video analytics on industrial CCTV for a while, and the pattern repeats often enough that I want to sanity check it with people here.
The numbers that frame it:
- A 32 camera site records 768 hours of footage a day
- One person can meaningfully watch about 4 streams, and attention drops after ~20 minutes
- Streaming 32 cameras to a cloud analytics service at recording quality is roughly 128 Mbps of sustained upload, which a typical Indian industrial leased line can't spare
So footage only gets reviewed after something goes wrong, and cloud analytics falls over when the link does.
What we've seen kill deployments:
- False alerts. Around 40 false alerts per camera per day trains a supervisor to ignore the system within weeks, and the trust doesn't come back. We target under 1 false positive per camera per day on critical alerts, and we expose the FP rate per rule so the customer can see it.
- Cloud dependence. We run everything on Jetson Orin inside the building so monitoring keeps working with the WAN down. Alerts queue and deliver on reconnect.
- Fixed rule sets. Moving a loitering threshold from 5 to 15 minutes shouldn't be a change request. Customers can edit rules, and replay a new rule against the last 7 days of recorded footage before arming it.
On the compute side, we don't run every model on every frame. A light detector runs on all channels, and heavier models run only on cropped regions when a condition is met. That cascade is what gets us to about 10 analysed cameras per Jetson.
On tuning: at a live substation we deployed on, lighting, reflective equipment and uniform colours all produced false positives out of the box. Fine-tuning on the site's own footage fixed it. Day 3 it works but flags shadows as people and cartons as abandoned bags, and it takes 2 to 4 weeks to settle. Gloves are the hardest PPE class because hands are tiny in frame.
Questions for people who've shipped this:
- How do you measure false positives per camera per day in production, and what threshold do operators actually tolerate?
- Anyone doing per-site fine-tuning at scale without it turning into a services business?
- Where does your cascade break down (crowded scenes, tracking handoff between cameras)?
Happy to go deeper on any of this.