Re: Hand detection, PCA & tracking

Hi,

i'm looking to be able detect human hand.
what would be the best bet ? using haarcascades xml file or camshift ?
is there a xml file allready made ?

thx in advance :)

Yuval


--- In OpenCV@xxxxxxxxxxxxxxx, "rjdpauw" <rjdepauw@xxxx> wrote:
>
> 
> Hello Juan & Jeff,
> 
> I have currently built a hand detector that uses haartraining combined
> with a particle filter for the tracking. The next step is to do the
> gesture classification. Since I only want to differentiate between 2
> gestures I'm thinking of PCA using two eigen object means.
> 
> Greetings,
> 
> Rob
> 
> --- In OpenCV@xxxxxxxxxxxxxxx, "juanwachs" <juan@xxxx> wrote:
> > 
> > Hi Jeff!
> > Well, I used once 'TemplateMatching" and also got terrible bad 
> > results. But you can check yourself to know whether is your bug, or 
> > it is only a bad idea to use the TemplateMattching. To do this, try 
> > to match between the original image that you are looking for, and the 
> > same image. You must get a value of '1', which is perfect matching. 
> > Then, if use use it with test images, you will get values from 0 to 1 
> > according to the similarity.
> > Again, I got very bad results, when I used it in the past.
> > May be a better idea is to extract some features from each sample, 
> > and feed a K-means algorithm. I think that this will be a better idea!
> > Take care,
> > Juan
> > 
> > --- In OpenCV@xxxxxxxxxxxxxxx, "Jeff Ng" <csisjeff@xxxx> wrote:
> > > 
> > > Juan,
> > > 
> > > I am doing similar things.
> > > I try to use template matching(provide by opencv) instead of c-means
> > > or k-means. Does it sound reasonable? What do you think?
> > > 
> > > Also, have you tried cvMatchTemplate. I got a small area, say x, 
> > from
> > > a pic, say X, and try to match x with X using the function. But the
> > > result floating point numbers all give the same value. I cannot get
> > > any information from the result. Do you know where is my problem?
> > > 
> > > Thanks.
> > > 
> > > Jeff
> > > 
> > > --- In OpenCV@xxxxxxxxxxxxxxx, "juanwachs" <juan@xxxx> wrote:
> > > > 
> > > > Hi Robert,
> > > > Well, more or less I'm trying to do the same: track hand and 
> > > > recognize gestures. There are two approaches that I think may 
> > achieve 
> > > > this goal:
> > > > 1) Track the hand by skin color or movement or both together (I 
> > use 
> > > > camshift which works nice)
> > > > 2) Once the hand is resting, call to the recognition module. For 
> > > > this, you need to: segment the whole hand from the background, 
> > and 
> > > > then call to a classifier. I'd suggest k-means or fuzzy c-means.
> > > > 
> > > > The second approach is to use Haar classifier. It will find the 
> > > > gestures, withuot motion or color information.  
> > > > 
> > > > I already did the approach 1, and find that it is relatively 
> > fast, 
> > > > but inaccurate.  
> > > > The seond approach should be more accurate, but probably it will 
> > be 
> > > > slower (since you have to train N classfiers, as the number of 
> > > > gestures that you have).
> > > > Probably the best is to combine the two approaches. 
> > > > I'll try myself the method of Haar classifier, but this may take 
> > some 
> > > > time.
> > > > Good luck!
> > > > Juan 
> > > > 
> > > > 
> > > > --- In OpenCV@xxxxxxxxxxxxxxx, Robert Jan de Pauw <rjdepauw@xxxx> 
> > > > wrote:
> > > > > Hi all,
> > > > > 
> > > > > I am currently using the OpenCV library to build an advanced 
> > user
> > > > > interface using hand gesture recognition. I already have a 
> > detector 
> > > > up
> > > > > & running thanks to the haartraining 'suite'. It is currently 
> > able 
> > > > to
> > > > > detect only one position of the hand. At first I thought of 
> > > > building a
> > > > > detector able to detect multiple hand gestures but that didn't 
> > > > really
> > > > > seem to work out.
> > > > > 
> > > > > My strategy is the following:
> > > > > 
> > > > > 1. Detect the hand
> > > > > 2. Track the hand to make up for undetected hand gestures
> > > > > 3. Distinguish between gestures through euler-distance & PCA (or
> > > > > perhaps kmeans ?)
> > > > > 
> > > > > While the OpenCV library seems to support tracking, PCA and 
> > kmeans,
> > > > > information on these subjects is lacking. I therefore have a 
> > couple 
> > > > of
> > > > > questions:
> > > > > 
> > > > > 1. Suggestions for improving the hand detector (i.e. enabling 
> > it to
> > > > > detect multiple gestures).
> > > > > 2. What's the best tracker to use and how to use it (e.g. 
> > sample)?
> > > > > (Condensation is not supported anymore ?)
> > > > > 3. How to use PCA (e.g. sample)?
> > > > > 
> > > > > I know that I'm asking a lot and I don't expect answers to all 
> > of my
> > > > > questions. Any help would be appriciated.
> > > > > 
> > > > > Thanks a lot in advance,
> > > > > 
> > > > > Rob
>






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