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Posted: Thu Oct 13, 2005 8:18 pm
by jameswilson
My experience of detection setup in the past has used blocks, you select a block size covering the image, ie little changes needed 9 x 9 lots of little things to mask 64x 64 then you click on each block either on or off. One system i used a while ago had a sensitity setting per block but it was a powerful £18k vision systems thing
Your idea sounds cool but i only use it for activity detection false alarms aint that important to me normally.
James
Posted: Fri Oct 14, 2005 7:52 pm
by Blazer
That would certainly make it more "user-proof", as then you wouldn't have to deal with issues caused by people using improper format mask files, upload problems, etc. I would envision the optimal way to define zones would be to just "draw" enclosed polygons onto a static frame (might need to have an option to "merge" polygons so that you can make a single zone around a curved area). Another way would be to overlay a fine-meshed grid over the image, and the user toggles the "pixels" of the grid on or off, using different selectable colors for different zones, etc.
The only problem I can forsee with that method (grid), is how to you make zones within zones...I guess you could have a "layer" setup where users can define overlapping zones layer by layer.
I imagine this will have to be done in Java...fortunately I think there are lots of opensource java "drawing" applets that you could probably borrow code from

Posted: Sat Oct 15, 2005 9:00 am
by lazyleopard
Anything that allowed for non-rectangular zones would probably help, as any view from an elevated camera position is going to suffer from perspective effects. Rectangular zones aren't good for covering those. Even options just for elliptical and trapezoidal zones would help. My driveway and front garden looks a bit like this:

and in strong sunlight, like this:

The hedges, window frames, and places that gets shadowed by the shrubbery all produce plenty of false events.
Posted: Sat Oct 15, 2005 10:47 am
by jameswilson
but if the rectangles were small enough you could.
say if the rectangles were 4x3 pixels. i liked the option of turning diferent areas into diferent motion types by use of colours earlier. And if you dont like rect what about circles.
James
Posted: Sun Nov 20, 2005 1:05 pm
by lazyleopard
These are the sorts of zone shapes I'd create if I could build zones from arbitrary polygons.

Posted: Sun Nov 20, 2005 1:19 pm
by zoneminder
Yes, that is a perfect one. If I could guarantee that everyone would do them as tidily and consistently as that it would be no problem.
I'm going ot address this feature next anyway I think and there may well be more than one option available.
Phil