# Tracking 3d coordinates

hi there,

im trying to track people in space (an empty hall); at least x and y, but best would be z/height as well. i understand i can’t use normal tracking, as i would need at least 2 cameras to analyze the depth, right? anyone tried this?
or should i go for sensors? don’t know about sensors at all- is there a way to achieve my aim?

depth?
you wanna know when somebody starts flying?
wow. wanna be there.

what precision in height information do you want/need?

somehow should be something possible.
i always wanted to experiment a setup with stereovision.
but i didn’t have 2 equal cams and the time for this by now :^(

@kalle: hm, maybe we’ve confused something with the coordinates, or i simply misunderstand you…if left and right is x, the height of people is z and the depth is y, change of depth would mean people coming towards or moving away form the point of view- that’s how i meant it, no flying, yet ;)

i could get x and z with vvvv-tracking methods, but not y- at least not without a second camera high up in bird’s view (but my room is not high enough for this…)

so what i thought of was tracking x and z with some tracker and use something like one or more distance sensors to get y, what do you think? any thoughts/infos very appreciated as i have no experience with sensors at all.

thx.

You could place a second camera on another wall but it would be hard to track several people if they stand in line according to the camera view. It depends on how precise information you need. The best would be a camera in the ceiling to detect x/y coordinates of people from above and then a camera at a wall to detect their height.

But if you try to visualize a box, imagine having a camera at the top edge and a camera at the left edge, both directed at the center of the box. Then you could detect x/y/z, one camera for x/z and another for y/z.

I haven’t tried doing tracking with multiple cameras though so I cannot tell if it would work. Doing it with sensors would probably be hard in a big room and not as precise. If you need sensors you can use an Arduino though, google it. :)