ZoneMinder Forums

How do I handle the situation when my camera automatically switch from day to night vision - this causes a lot of changes in the picture but I do not want it to trigger an alarm...

- Trist

Create small zone Preclusive in that part of a picture where is guaranteed there is no movement, but the picture (brightness) varies at switching modes, for example in a upper corner.

Never had much luck getting precusive zones to stop light-on and light-off events, myself. They may suppress the instant itself, but the un-even way in which the rest of the field slowly gets merged into the reference frame usually means that an event is triggered a few frames later.

You need to ensure that your preclusive zone is more sensitive (ie. has a smaller threshold and percentage values) than your regular zones for them to work effectively.

They're not a panacea though, and as with all tuning problems, the first step is to decide exactly what the qualities of changes you do or don't want triggered are. If you can't discriminate them in English (or whatever language you use) then the chances are you won't be able to set up a config that will do what you want.

Phil,

Is there a way of getting any diagnostic images that show the current-reference differences?

Even better, is there a way to see them in the lead-in to an event as well as when an event has been triggered?

Mental note: When the light off/on events are triggered by a PIR switch it is probably not sensible to have a preclusive zone preventing zoneminder from recording the events....

It seems to me that what's needed for light on/off events is a way to get ZoneMinder to flip the reference frame percentage to 100% for one frame only...

Must get back to the day/night settings hacking too...