currently I’m experminenting on an idea and found vvvv could be the best tool for it! And I really like it so far, but there are some questions regarding motion tracking.
So what I want to do is getting data from two (glowing and differently coloured) objects moving in front of a camera. The data should be for each object: x/y coordinates, speed, and ‘istracked’-status.
I already tried the CamShift Module, but there are some issues. I would appreciate if you could help me with this:
.I don’t need any video output, just the data from the objects. BUT I need them preferably close to realtime, so everthing which takes processing time should be eliminated. what could that be? I tried to remove video output but then the tracker doesn’t work anymore.
.I need the maximum resolution of the video (PAL) input to get fine-grained position. But as soon as I increase the res to more than something like 500x400px there is a 1,5 second delay.
.Is it possible to “smooth” data? E.g, the captured x/y coordinates “flacker” or “flutter” +/- 5 points even if the object doesn’t move (probably because of the noisy video input).
.How can I detect two objects?
.How to speed up the motion-tracking thing in general? :) Oh, and i don’t intend to buy an new pc :)
Ok, thats all for now. Maybe these are just stupid beginners questions, but I would appreciate your answers anyway :)
.Is it possible to “smooth” data? E.g, the captured x/y coordinates “flacker” or “flutter” +/- 5 points even if the object doesn’t move (probably because of the noisy video input).
This is common behaviour of most sensors. Filter the resultiung values - with oscillator or damper for example.
Try to optimize the image quality of the camera in general:
Make sure to light your scene well. Noise increases dramatically if there is not enough light.
use a consumer handycam (3CCD etc) with a grabber card instead of a webcam
or a professional camera with hi-def optics even
.How can I detect two objects?
Use ColorTracker instead of camShiftTracker?
They’re spreadable, no?
.How to speed up the motion-tracking thing in general? :) Oh, and i don’t intend to buy an new pc :)
use lower resolutions & more interpolation
try boost (vvvv)
test your patches’ performance using CTRL+F9 / perfMeter (Debug)
I managed to get smooth values and using a high quality 3ccd-dv cam really helped a lot! The objects are seldf-illuminated, so they’re quite easy to track.
But I don’t understand what you intend with: “They’re spreadable, no?”…
Both, camShift and ColorTracker accept one input and output one value per parameter. What I need to achieve is to get the speed and coordinates of two differently coloured object at the same time from the same video-frame. How does spreading help?
I dont know how fast your objects will move. Think, with a MiniDv you will limited to 25fps (Best results with Progressive Scan).
If you need a faster tracking the best is to take Philips ToUCam Pro II (something around 25eu at German Lidl). It can achieve up to 90fps. But resolution will reduce dramatically, because its USB 1.1. USB 1.1 can give you just 5fps uncompressed. So the images have a lot of Megapixels, but they are quite fast.
