Having a difficult time understanding and applying how to tune the zones for good detection.
In the sample frame I've walked into my side yard through the gate directly behind me 30 feet or so This is the first frame that showed up as an alarm frame. I'd really like it to alarm when a human sized object comes up to the gate. Or at least when they are passing through the gate. I haven't quite gotten all the different options in the zone settings figured out.
Is there one or two values in there I can start adjusting up or down in small increments till I find a good sweetspot?
Zone tuning
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BiloxiGeek
- Posts: 271
- Joined: Tue Feb 11, 2014 2:04 pm
Zone tuning
- Attachments
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- The zone settings for the camera.
- zone-settings.png (227.22 KiB) Viewed 2866 times
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- The first alarm frame.
- Too-Late.jpg (44.43 KiB) Viewed 2866 times
Re: Zone tuning
I'm pretty new at this, so I might not do it in a "Zoneminder" way. But from what I have experienced, the zoneminder motion detector react to a certain percentage of difference in the zone. So if you have a large zone for most of the image, stuff that are far away, and therefor small, will be less likely to trigger an alarm. What I have done, when I am dealing with large distances, is cutting the zones up in far, near and sometimes center zones. Then I tune the zones on sensitivity, zone by zone, beginning at high sensitivity. When I get an event with low alarm frame count, I check the alarm frame to see what caused it. If its just image noise, I reduce sensitivity one level.
If someone moves in the far zone, and it does'nt get picked up because I got the sensitivity too low, then I start considering constant recording. The image may simply be too noisy for the motion detection to see the difference between pixel noise and moving things.
Using more than one zone might be a good idea anyway, and I do it a lot for fast event searching. By creating a separate zone for your trailer, and another one for the fence, you will be able to sort out quickly if the events are of any concern to your property.
If someone moves in the far zone, and it does'nt get picked up because I got the sensitivity too low, then I start considering constant recording. The image may simply be too noisy for the motion detection to see the difference between pixel noise and moving things.
Using more than one zone might be a good idea anyway, and I do it a lot for fast event searching. By creating a separate zone for your trailer, and another one for the fence, you will be able to sort out quickly if the events are of any concern to your property.
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BiloxiGeek
- Posts: 271
- Joined: Tue Feb 11, 2014 2:04 pm
Re: Zone tuning
Is there additional overhead when using multiple zones?
I did make one change this morning, I bumped the Alarm Frame Count from 1 to 3. A lot of the events I was seeing were due to a flicker in the image, some sort of auto iris thing in the camera I believe. They only lasted for one frame in most cases. Another cause I was seeing was the stupid bugs doing close up fly-bys on my cameras at night. Again they stayed in frame for one or two frames typically.
Changing the frame count seems to be working really well so far.
I did make one change this morning, I bumped the Alarm Frame Count from 1 to 3. A lot of the events I was seeing were due to a flicker in the image, some sort of auto iris thing in the camera I believe. They only lasted for one frame in most cases. Another cause I was seeing was the stupid bugs doing close up fly-bys on my cameras at night. Again they stayed in frame for one or two frames typically.
Changing the frame count seems to be working really well so far.
Re: Zone tuning
I have not noticed any big changes in performance.
If you are balancing on the edge of acceptable load, then drop framerate a bit. The difference between 7 and 10 fps isn't much, concerning the types of evidence you would get from that camera. But it will probably affect the load on the server quite a bit.
To finish, first you have to finish, as they say. I would get the people detecting problem solved first, because that is the result you need from the camera. Then I would start tuning for performance and false positives, while always going back to see if any changes I made affected the ability to detect people at the gate.
If you find out that the "detecting people at the gate" solution can't be done without getting too bad framerate or too many false positives, then your problem needs another kind of solution. Then you may need more resources on your server, or you may have to rearrange your cameras so that one camera may focus on the one job of detecting at the gate, while another camera has a larger overview in the garden.
But I bet you can get good results on that image by just making a small zone on the grass on the inside of the gate.
If you are balancing on the edge of acceptable load, then drop framerate a bit. The difference between 7 and 10 fps isn't much, concerning the types of evidence you would get from that camera. But it will probably affect the load on the server quite a bit.
To finish, first you have to finish, as they say. I would get the people detecting problem solved first, because that is the result you need from the camera. Then I would start tuning for performance and false positives, while always going back to see if any changes I made affected the ability to detect people at the gate.
If you find out that the "detecting people at the gate" solution can't be done without getting too bad framerate or too many false positives, then your problem needs another kind of solution. Then you may need more resources on your server, or you may have to rearrange your cameras so that one camera may focus on the one job of detecting at the gate, while another camera has a larger overview in the garden.
But I bet you can get good results on that image by just making a small zone on the grass on the inside of the gate.
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linuxsense
- Posts: 374
- Joined: Wed Nov 07, 2007 1:59 am
- Location: Huntington Beach, California
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Re: Zone tuning
Tuning is a bit of a black art. It can be made quite difficult if you have cameras that display artifacts or tend to have sudden brightness and/or contrast changes. A few of my analog cams fall into that category. And trees. Freekin' trees. At least half of my cams have trees in most of the view so a decent breeze results in non-stop alarms. What I do these days (since I have a silly amount of storage) is run everything on 'Mocord' with reasonable zone sensitivity settings. That way everything is recorded and 99% of the time ZM will 'alarm' enough so I can find interesting events.