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View Full Version : Re: Algorithms for image processing in markerless gait analysis



Riccardo Trocca
09-08-2000, 02:23 AM
> I am developing a markerless gait analysis system using image processing
> techniques to locate the joint centres for tracking. I am hoping to achieve
> this by fitting a simplified model of the leg (literally just four lines in
> the 2D plane) to the actual footage of the patient's leg. I have managed to
> successfully pick out the patient from the background of the film clips but
> I am having trouble actually fitting the model to the footage without manual
> intervention. I was wondering if anyone has tried this technique before and
> how they managed this particular problem. I am really looking for source
> code or algorithms at this stage as I have read several papers on the
> theory.

I'm struggling with the same problem even if applied to the whole body.
I can provide you some links I've found useful.

Hough transform
http://www.cogs.susx.ac.uk/users/davidy/teachvision/vision4.html
Motion
http://www.cogs.susx.ac.uk/users/davidy/teachvision/vision6.html

Adrew Blake
Introduction to Active contours and Visual Dynamics
http://www.robots.ox.ac.uk/~ab/dynamics.html


Judit Verestˇy and Dmitry Chetverikov
Fearture Point Tracking Algorithms
http://www.dai.ed.ac.uk/CVonline/LOCAL_COPIES/CHETVERIKOV/psmweb/index.html

Image Processing Fundamentals
http://www.ph.tn.tudelft.nl/Courses/FIP/noframes/fip-Contents.html

The Condensation Algorithm Home Page
http://www.dai.ed.ac.uk/CVonline/LOCAL_COPIES/ISARD1/condensation.html

Jaewon Shin
CONDENSATION for Visual Tracking
http://graphics.stanford.edu/~jwshin/cs223b_final_report/node2.html


I think that the techniques that better fits your problem is Condensation.
Anyway, as you can see some papers are from a site called CVonline. In the
same site I found a short paper about gait analysi, really interesting
albeit short. It says that also the computing of Optical Flow is an
interesting technique to collect info about gait.
Try this other link too:
Stan Birchfield
KLT An implementation of the Kanade-Lucas-Tomasi feature tracker version
1.1.5
http://www.vision.stanford.edu/~birch/klt
Then on the Intel site you can find a really huge library for image
processing, completely free and really powerful.
Hope all this is useful to you.

Riccardo Trocca
rtrocca@libero.it
Laboratory of Musical Informatics
DIST
University of Genoa
Italy

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