[sldev] Anyone here with OpenCV experience?

[Jan Ciger]

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Philip Rosedale wrote:
> Have you seen this video...  http://www.youtube.com/watch?v=r7Gn2TyEyHw
> 
> It is a cheap logitech camera tracking a head and head rotation really
> well (which you can see by the registration quality of the video overlay).
> 
> This is what we want - simple head position and movement tracking from a
> camera.  I suppose we could just use the logitech API but that would
> restrict us to their cameras.  I believe that the code they ship with
> their cameras is based on OpenCV?  Hence the question. 

I do not know if the code is based on OpenCV (probably not - license and
all), but this is quite easy to do. Most likely they are using the well
known CamShift algorithm for face tracking.

Paper:
http://download.intel.com/technology/itj/q21998/pdf/camshift.pdf

US. Patent:
http://www.google.com/patents?hl=en&lr=&vid=USPATAPP9079917&id=kaWEAAAAEBAJ&oi=fnd&dq=bradski+camshift

Camshift gives you an orientation angle of the face elipsoid + 2D
position + relative size that you can use to judge distance. OpenCV
implements this algorithm (Gary Bradski is one of the main authors of
OpenCV).

I was using it before for simple tracking and it works reasonably well
if you have good lighting conditions. It is fairly easy to use - there
is actually a working example of it in OpenCV for face tracking.

Regards,

Jan




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