I am using vitamindvideo on a PTZ camera that patrols. I get quite a bit of false alarms (for people detection as well) during a pan and at night when a light turns on against certain background objects (e.g. trees). What would really be helpful (and should be easy to code) would be a setting like "ignore objects that do not move for at least X seconds." That way transients when a light turns on or during a brief pan would be eliminated from detection. There is already a setting for "Include objects visible longer than" (and I thought that might be what I was looking for) but it either doesn't work or does something else - which by the way is not covered in your documentation.
Thanks.
False alarms
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4 posts
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ryan - Posts: 1015
- Joined: Wed Aug 25, 2010 2:52 pm
- Location: Palo Alto, California
Re: False alarms
Hi brian,
PTZ and VDV are definitely not very compatible. VDV must learn the scene to detect other objects and does not expect the scene to change. Panning throws this off, and it takes a bit to decide that the scene itself has changed and to merge all of the observed 'objects' into the background and reset the scene. It would be possible to notify VDV that a pan is occurring, but this would really need to either be done by the user, or by VDV receiving a notice from the camera or being the one controlling the PTZ. A pan can look very similar to an object suddenly filling the frame. VDV would also need to explicitly know that this was occurring as it would throw off a majority of the rules, such as boundaries and regions.
Sorry information on "ignore objects" is a bit hard to find in the docs, described here under "duration" - http://www.vitamindvideo.com/support/re ... rules.html
and in a tip on this page - http://www.vitamindvideo.com/support/re ... ps_19.html
"Filtering out objects that are only briefly visible can eliminate many clips. You may not be interested in cars or people passing by, or you may have false alerts that sporadically appear for a second or two. You can filter out these cases by creating a rule that has a duration setting (e.g., only show objects visible longer than 5 seconds)."
Are you not seeing that behavior?
PTZ and VDV are definitely not very compatible. VDV must learn the scene to detect other objects and does not expect the scene to change. Panning throws this off, and it takes a bit to decide that the scene itself has changed and to merge all of the observed 'objects' into the background and reset the scene. It would be possible to notify VDV that a pan is occurring, but this would really need to either be done by the user, or by VDV receiving a notice from the camera or being the one controlling the PTZ. A pan can look very similar to an object suddenly filling the frame. VDV would also need to explicitly know that this was occurring as it would throw off a majority of the rules, such as boundaries and regions.
Sorry information on "ignore objects" is a bit hard to find in the docs, described here under "duration" - http://www.vitamindvideo.com/support/re ... rules.html
and in a tip on this page - http://www.vitamindvideo.com/support/re ... ps_19.html
"Filtering out objects that are only briefly visible can eliminate many clips. You may not be interested in cars or people passing by, or you may have false alerts that sporadically appear for a second or two. You can filter out these cases by creating a rule that has a duration setting (e.g., only show objects visible longer than 5 seconds)."
Are you not seeing that behavior?
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brian.f.hearn - Posts: 3
- Joined: Wed Feb 06, 2013 10:58 am
Re: False alarms
Ryan, it sounds like the existing ignore feature is what I need to try again. I have it set to 3 seconds and it still picks up "people" during some pans and at night when a light comes on - especially against trees. I get what you are saying in terms of VDV having to analyze the scene and where pans or transients might confuse it - but that's precisely what I would expect an [ignore anything detected that is transient for less than X seconds] to address. I will try bumping the delay up to 5 seconds and retest. Thanks.
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brian.f.hearn - Posts: 3
- Joined: Wed Feb 06, 2013 10:58 am
Re: False alarms
Ryan--
Just to give you an update. After trying everything from increasing the "include objects visible longer than" setting, to better lighting, still no joy. VDV fires a false alarm in low light when there is a flash (like from an outdoor light being turned on) to a car headlights. It also fires a false-alarm on most PTZ movements. I understand (as a software developer) that the motion detection algorithm is not trivial but it seems a setting such as: "ignore detection unless motion exceeds X seconds" should be doable. The PTZ motions are very quick, less than 2 seconds. If there was a capability like this, then both flashes in low light and PTZ movements could be ignored. Please consider this in your work to improve the product. Thanks.
--Brian
Just to give you an update. After trying everything from increasing the "include objects visible longer than" setting, to better lighting, still no joy. VDV fires a false alarm in low light when there is a flash (like from an outdoor light being turned on) to a car headlights. It also fires a false-alarm on most PTZ movements. I understand (as a software developer) that the motion detection algorithm is not trivial but it seems a setting such as: "ignore detection unless motion exceeds X seconds" should be doable. The PTZ motions are very quick, less than 2 seconds. If there was a capability like this, then both flashes in low light and PTZ movements could be ignored. Please consider this in your work to improve the product. Thanks.
--Brian