Negative sensitivity area in motion detection to suppress recording

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Harald Klein

I have a camera in a staircase which always triggers motion detection when the staircase lighting turns on and off. Back when using zone minder I did solve that by using a "negative" zone. When pixel changed there, it did ignore motion in the other zones of the image. By using a small area up the wall that nobody would reach, I got perfect results. Hence it would be great if NX Witness could implement the same. On the motion page, one could introduce a -1 sensitivity, which would then show the same behaviour.

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    Norman Graafsma

    Hi Harald, 

    Great suggestion to improve our VMS. 
    I submitted your ticket to our support portal to share your suggestion with our dev team. 

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    Tuli Dem

    Harald,

     

    You can acheive that just by selection that area in the motion menu and setting it to 0.

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    Harald Klein

    no, that wouldn't achieve the same. I can't set a sensitivity of 0 to the whole image, because then no motion would be detected. But if pixels change in that specific "negative" area, it is for sure the ceiling light switching on or off, and not somebody walking in front of the camera. 

    From the Zoneminder Wiki:

    But hey what's that preclusive zone in your image at the start of this article?

    ZM allows us to specify a zone where should an alarm occur, it suppresses alarms in that zone and all other zones in the monitor. I've set it to cover my recess lights. So if someone turns our lights on, I won't get an alarm.

    That worked a treat with ZM for my use case. Now I'm searching for the same feature in NX Witness. A negative sensitivity would allow to define such preclusive areas. Movement there would suppress movement detection in the other areas.

     

     

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    Tuli Dem

    You didn't "read" what I wrote... I said that you could set 0 sensitivity to a "specific" area. That should achieve what you are requesting.

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    Harald Klein

    I did read what you wrote. But I'm unsure if you do understand the objective. The ceiling light, when being turned on, will change *all* pixels in the image. So just having a specific area set to 0 sensitivity, will not prevent motion detection to trigger. You can try that on your own system. Enable motion detection for a specific area, and then turn the light on at night. It will trigger. Having a specific area high up on the wall - where usual motion does not occur -  set as "preclusive" area, e.g. by sensitivity -1, would prevent motion detection in other areas set with different sensitivity. Did that explanation clarify things?

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    Glen Harrison

    Hi Harald

    yes I agree , mobtotix cameras have this option , to qualify a small region somewhere where motion is not expected.

    Great for controlling motion when sun goes behind clouds and rain etc . 

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    Sergey Bystrov

    Harald, 

    Here is another idea. 
    So there are false positive based on lights on/off or camera goes to day/night.

    Based on our observation, such events trigger luminance(brightness) change across all image. 
    So would it be better if we ignore MD if luminance changed across all image?

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    Eddy G

    Any updates on this request?

    I’m currently (very early) in my evaluation of DW Spectrum as a replacement for ZoneMinder (thank you for making Linux—and especially Docker—a first-class citizen!) and found the “ignore all motion if there’s a change here” mask in ZM useful for suppressing bogus motion triggers for things like day/night transitions (when the camera auto-switches from color to B&W).

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    Sergey Bystrov

    Planned for 4.1( March). We just will detect false positives in case if some threshold has motion( like motion is in 90% of the frame). 

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    Marc R

    Will this be fixed soon? I get the worlds upside down so 4.1 is delayed.  

    I'm evaluating as well, and really don't like that places where I have automatic lights (they go on and off with motion sensors) it constantly records when the turn off (no one is around, so no camera motion, but lights turning off triggers Nx to record as the image changes).

    Hopefully you implement a % of pixels like many other do. or better yet, can you detect that it was lighting change (i.e. colors became darker)?

     

    Thanks

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    Norman Graafsma
    • Edited

    Hi Marc R

    This feature made it into 4.1. You can download and try 4.1 Beta already. This version can be downloaded through my.networkoptix.com/#/download and then go to the tab Beta. 

    As the release note mentions: 

    "Server Side Motion Detection improved - False positives' detection like turning on/off lights or switching camera day/night mode are now ignored."

    Besides that, we are working on more integrations for in-camera analytics since such events are more reliable than generic motion detection. 

    Currently, we offer in-cameras analytics for Axis, Dahua, Hanwha, and Hikvision. But there are also plenty options to add in-camera analytics as a generic event, like Bosch, Milesight, RIVA, UDP Technology, and VCA Technology.  

     

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