different usage

djsb · Post by **djsb** » Wed Sep 21, 2005 11:53 pm

Hi all,

I would like to use zoneminder to have the following behavior:

- detect an object that enters a specific zone
- detect if this object stays longer that X seconds in this zone
- create an automated and dynamic new zone around the object with a space interval. In which it can move a little, but if it stays X seconds inside the new dynamic zone it will then enter in alarm mode.

I would like to use this in an investigation project about detecting microscopic particles laying in (getting drawn) the bottom of the liquid they're in.

Could this be done with zoneminder "out of the box"?

I don't know if i have explained myself..

Post by **cordel** » Thu Sep 22, 2005 2:07 am

You can do something simular with ZM as it is. Since it's inception is for security some of what you are looking for is already there just not in the fashon you might be looking for.

1)Zones are already part of ZM see the documentation as it is described there very well.
2)It could do this if you turned image blending off it would stay in alarm till the object left.
3)With blending ON which is based on percentage of each frame captured. the referance image would be updated till it is part of the referance image. So this would be the one point that would be hard to acomplish to create an alarm if the object sits there for a specified time.

In order to do your third point there might have to be a second referance image made are you would have to not update the referance and go through the alarmed images. You might be able to filter through these useing the scoring methods in your search filters. This is a bit outside of what it was designed for but I think you might be able to come close. There are some of our users that use the software a bit diferantly, and could have some other good sugestions for you.
Regards,
Cordel

Post by **zoneminder** » Thu Sep 22, 2005 1:50 pm

It's probably not supported directly 'out of the box' but might not take a huge amount of modification to do it. I'm not 100% sure I follow the required behaviour though, can you elaborate a little (any image examples?). What is the overall effect you are trying to acheive? Are you talking about one object per image or several? Will overlap etc?

Phil

djsb · Post by **djsb** » Tue Sep 27, 2005 12:56 am

Here is a diagram that represents my needs for this investigation project.

What should be the main changes to zoneminder to get this type of feature? Don't you think this could be an interested feature even for video surveillance?

Post by **zoneminder** » Sun Oct 02, 2005 10:49 pm

Ok. Thanks for posting that. I understand a little more what you are after. I'll see if I can add something that might help you if I can think of a generic method that might extend to other applications

Phil

djsb · Post by **djsb** » Mon Oct 10, 2005 1:53 pm

This could be usefull for detecting stopping presences. You might have a zone that if you stay it will enter in pre-alarm and only enter in alarm if the object stays there for more than x seconds.

Imagine a road where you need to know if a car stopped in the middle of the road. The car entered the pre-alarm zone and then if it does not move that it has probably stoped.

There are a lot of generic usage of this function.

jameswilson · Post by **jameswilson** » Mon Oct 10, 2005 2:06 pm

there is and its called non movement detection. We use it in public places around bins, benches etc so that if an object is introduced it starts a timer if the object is still there after your non movement alarm delay it goes into alarm. This isnt an alarm as zm is used to though because under these circumstances a higher response is required, (usually a guard). NOw great feature that on cctv is arelyt used. I understand it would be useful to you. Usually only found on the top end viseon systems motion detector racks. (starting at over £12k per rack. 12k gets you 1 alarm input lol)

James

Post by **zoneminder** » Mon Oct 10, 2005 9:13 pm

You could probably kludge something like this now. You could set a very low reference blend percentage, meaning the reference images would remain mostly static only responding to overall lighting changes. Then set a large minimum alarm frame number to only catch alarms that were long lasting. You'd have to have big buffers though for this and so would probably want a slow frame rate to compensate.

Phil