Motion Capture missing footage seen in Motion Events

nagar
nagar
in SecuritySpy

Using SecuritySpy for the glamorous task of determining which of four dogs is peeing in the house at night. Last night I was mystified that the Motion Capture movies completely missed the event despite a camera having a clear view of the scene of the crime and the dogs' motion being across the field of view of the camera.

I also have Continuous Capture enabled and using the Motion Events filter on the server Mac I was able to quickly see the crime take place. My question is why the crime triggered a Motion Event but not Motion Capture.

Pre-capture was set to two seconds and post-capture set to ten seconds. The crime occurred within ten seconds of the previous motion. I'm wondering if somehow this is the problem, though to me that would be unexpected behavior. I tried reducing the post-capture to four seconds (triggering a warning from SecuritySpy) and will see if that helps.

Perhaps the algorithm for Motion Event detection is different than the algorithm for Motion Capture triggering? In this case at least the Motion Event detection worked far better.

As an aside some years back my security company had advised always using continuous capture for security cameras since motion capture often misses what you need to see. I can see what he meant.


Thanks, Bill

Comments

  • Ben
    Ben

    Hi Bill,

    The fact that the motion event is present in the Continuous Capture (CC) file means that SecuritySpy correctly detected motion for this event (/crime!). Are you sure that this event is not in any of the Motion Capture (MC) recordings - perhaps at the tail end of one that started a bit beforehand? If not, one explanation for this could be if you have enabled AI object detection for the MC trigger, as this is an extra step beyond pure motion detection that determines whether a file gets recorded or not. For example, if the Animal detector is enabled, it could be the case that motion was detected (hence the presence of the motion event in the CC file), but an animal wasn't identified (hence the lack of an MC file), perhaps due to low light or an odd angle that prevented the AI from detecting an animal.

    I would not recommend reducing the post-capture time - this will make it more likely to miss events, not less likely. The fact that the event happened soon after a previous recording would not alone prevent it from triggering the next recording.

    SecuritySpy's algorithms are highly accurate, but no algorithm is perfect. There is always a tradeoff between minimising false positives (erroneous recording/notifications) and minimising false negatives (missed events). Yes, CC recording is the only way to fully ensure that everything interesting is recorded, at the expense of much higher storage requirements of course!

    This may not help in your specific case, but we have some general advice in the manual here: Achieving Effective Motion Detection.

  • nagar
    nagar

    Thanks, Ben. Your support is awesome.

    I am certain this criminal event was not present in any of the motion captures since I carefully reviewed the continuous capture footage for the entire relevant period.

    You may have identified the reason: I had indeed enabled the AI detection of vehicles, people, and animals. I assumed that would simply categorize motion events and did not realize it could prevent motion capture if the motion trigger does not fit one of the selected categories. Reviewing the manual just now I see that you explained that clearly but I missed it.

    This criminal activity took place at night, with grainy, noisy black and white IR night vision, so I could see how the AI could be stymied. I am thinking of ultimately upgrading to more advanced, higher resolution color night vision cameras which might help with this.

    I will see how this works and report back. I have taken your advice and restored the 10 second post capture as well.

    With 8 TB hard drives costing around $100 these days for me at least the storage penalty of continuous capture seems unimportant, and as you say it can be a useful insurance policy.

    Thanks, Bill

  • Ben
    Ben

    Hi Bill, that must be the problem then. Yes, cameras with better night-vision would certainly be an improvement. Alternatively, you could install IR or visible LED lighting that automatically turns on at night in order to help your current cameras provide higher-quality images in low-light conditions. This would be inexpensive and would help a lot (plus, visible lighting at night is a good intruder deterrent as well).

    I totally agree with your comment about storage - it's amazing how far the costs have come down over the past few years. It's now possible to cheaply add large amounts of storage, and having the continuous files as well as the motion files is a good fallback.

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