My next strategy, when I have time to get back to it hopefully in a week or two, is to add a Nano running YOLO on a Nano to my system as a "verification" for persons detected with my current MobilenetSSD-v2 system. A single Coral TPU on an i7 miniPC is supporting 7 4K cameras and 8 1080p cameras with an aggregate frame rate of ~33 fps -- a bit over 2 fps per camera. The real limitation is the decoding of the 15 rtsp streams.
All my cameras are outdoor facing and my current "false positive" rate is less then one in 10 million frames (still not quite good enough), but I've gotten close as most of my false detections are from static objects that false detect as a person when the lighting is "just right". I filter them out by the bounding box coordinates. Specifically if the upper left and lower right coordinates match previously observed false detections to within a tolerance, I reject the detection and don't notify. Its been a couple of months since I've had to deal with a new false detection.
Since I upgraded to 4K camera I've also had to add a region of interest filter to make sure the lower right corner of the bounding box is on my property -- otherwise it regularly picks up people walking on the sidewalk across the street. A real detection, but also a real annoyance as these are normal activity of no interest to me.
So far the best use of my system has been the near instant notifications I get of the Mailman or Amazon making deliveries.
