Making motion detection actually work - any howto?

[lix]

Hello,

I've been running ZoneMinder 1.24.2 for about two weeks. I am using a 8-channel BT878 card with 5 analog cameras (all mounted outdoors) attached. The box is a Core i3, 2GB RAM, 5400rpm Sata disk running Fedora 14. The setup is really fast and works very well, and I'm really impressed with the ZoneMinder software and its features

However, after trying to make motion detection outside sensitive enough to detect a human while not causing any false alarms, I'm really starting to wonder if I will *ever* be able to make it.

Regardless of the image capture rate and any other setting I have tried I still get plenty of false alarms. 99% of the false alarms are caused by sudden changes in the lightning which causes ZM to trigger an alarm. It's also very apparent now when there is snow in my garden.

I have tried using different capture rates (1 fps to 25 fps), tried different "Alarm Frame Count" (from 2 to 5), AlarmedPixels and Blobs and different sensitivity settings for them. Also tried using multiple zones per camera with different sensitivity for the zones.

Below are current settings for one camera which gives false alarms.
Blobs
Min/Max Pixel Threshold 20/0
Filter width 5x5
Min/Max alarmed area 8/0
Min/Max filtered area 6/0
Min/Max blob area 5/0
Min/max blobs 1/0
Overload ignore frame count 0

Capture rate is 5fps
Reference Image Blend %ge 7
Alarm Frame Count 5

It gives me false alarms when outside light changes but then sometimes completely misses me when I'm walking by the camera. Simply not reliable enough.

So - are there any howto for actually tuning the motion detection feature so it can be used outdoors? I've searched the forum and the web but not found any definitive guide.

I would like to detect MOTION not the light changing. Is it at all possible?

As a last resort I'm thinking of putting up PIR detectors, connected to my 1-wire network and have them trigger ZM. But that's a fair amount of extra work so would like to use ZM as far as I can.

Any ideas?

Thanks,

//Henrik

[bb99]

I've read good results by adjusting "Overload ignore frame count". Search the forums, this subject is well covered.

[lix]

I've read good results by adjusting "Overload ignore frame count". Search the forums, this subject is well covered.

Thanks much! Of course it's the undocumented setting which does the magic

I've tried different settings for the "Overload ignore frame count" setting today but it's difficult to tell if it has actually made any difference. It's been steady cloudy all day so not as much changes to light as on a normal day. Hoping for a better test tomorrow.

I changed my settings to Best, Medium sensitivity but that's not always sensitive enough to detect a human walking pass the camera. So I've upped them to Best, Hi.

Thanks,

//Henrik

[bb99]

Your very welcome! Had similar problems myself (Robins scroging in my front yard when light was high) and the previous forums posts provided the answer. Just got to keep playing around, you'll come up with your answer. Important point is to known all the settings that are adjustable to correct this issue.