ZoneMinder Forums

AXIS 211A, in an external enclosure.

When it is getting dark, Zoneminder shows alarm for an hour or so.

It seems to trigger on some compression artifact - the picture shows shimmering grains when it its getting dark.

Tried both MJPEG and MPEG 4 - same outcome.

I could possibly detune the alarm trigerring but it is not all that satisfactory as it is (sometimes 'misses' a person walking slow, wearing gray clothes).

Actually, I have found an interesting solution (hack).

I have noticed that the automatic motion-activated outdoor halogen lamps ($35) do a decent job detecting motion and do not respond to moving tree shadows, video artifacts, Etc..

Also, the sensor works even during the day when the lights don't get activated.

So I took apart the sensor and connected a resistor and an optocoupler to the sensor's indicator LED. Connected the optocoupler output to the AXIS camera digital input and set up a notification to the zmtrigger.pl.

Very agile, no false alarms, I am very pleased with the outcome and will consider this mod for some more of my outdoor AXIS cameras.

Augustine Lehecka

Certainly an innovative hack. If you wanted to fix the problem in ZM there are a few things to try:

1) If its darastic quick changes you can try to just set the overload count to 1-3 frames so the motion has to continue for more than just a frame
2) If its the entire picture pixels are just changing slowly frame to frame generally upping the minimum diff will solve this issue
3) If its massive swings that 1 & 2 cant solve you could look at a max pixel limiting or if the camera covers a zone that never would have activity make it an inactive zone to exclude out the alarm if there is motion there.