Page 1 of 1

how to prevent alarm when the monitored area is dark

Posted: Wed Nov 22, 2006 1:50 pm
by tkalfaoglu
I found that if the area to be monitored is pitch black, the camera creates static noise, which triggers my ZM into recording. Any ideas what I can do?
Thanks! -t

Posted: Wed Nov 22, 2006 3:30 pm
by jamescollings
Maybe you could have a "night time" and "Day time" run states? Change the % of pixels that trigger an alarm for the "Night time" state, so that it will still trigger if someone turns "on" the light at night???

Of course, if this is a "dark room" which doesn't follow the light/dark phases of the sun... :-(

Posted: Wed Nov 22, 2006 3:40 pm
by tkalfaoglu
It's like every pixel jumps at every refresh (which is set for 1 second).
So no two picture is exactly alike.. It still did not work when I set it for
"Best, low sensitivity" preset, so I changed the 36% there to 50%, and trying it now. I wish I could run a "soften" filter on the image, then these noises would disappear..

Here is a sample - notice the fine background noise..
http://www.kalfaoglu.com/blanksample.jpg

Many thanks, -t

Posted: Thu Nov 23, 2006 9:37 am
by Tim_bots
maybe an other idea is to make an "preclusive" zone in the screen so when there is to much noise no event is generated.

(see readme for more info)

Posted: Thu Nov 23, 2006 10:28 am
by tkalfaoglu
Thanks a lot. I wish there was a feature to DISABLE alarm triggering,
if the pixel readings are below some number..
so that this dark-triggering problem would not happen..

-turgut

Posted: Thu Nov 23, 2006 11:18 am
by zoneminder
If you get a lot of 'snow' then the filtering on the zone should remove it. What settings are you using for your zone?

Posted: Thu Nov 23, 2006 11:23 am
by tkalfaoglu
actually, you can see my zone settings from the URL I gave, I only defined one zone (novice!), and there it is. I didnt realise we could filter it somehow.. great!
-t