Prev: Displaying multi-dimensional locations in 2D
Next: Time stamp ruing plots!
From: TideMan on 16 Jun 2010 18:24
On Jun 17, 10:00 am, "Manal " <be....(a)live.com> wrote:
> TideMan <mul...(a)gmail.com> wrote in message <9e9eebf5-6e64-468f-9dd7-b43f8be4d...(a)r27g2000yqb.googlegroups.com>...
> > On Jun 17, 8:36 am, "Manal " <be....(a)live.com> wrote:
> > > please guys help me
> > > I just need some one to explain it for me
>
> > I know nothing about star skeleton and I'm not interested in reading
> > the reference you posted.
> > But I can advise on zero crossing analysis.
> > Here is how you can locate them:
> > t1=y(1:n-1);
> > t2=y(2:n);
> > tt=t1.*t2;
> > indx=find(tt<0);
>
> > What it does is locate the places where adjacent points have different
> > signs (i.e., they are either side of the axis).
>
> thanks a lot for your replay
> thats what I want
> some one to give me the sample code for the zero-crossings
>
> but meaning of the zero-crossings for the difference function??????
>
> I've tried your code and it display all the vector content as "indx" value

You say that you've done this:
"I extracted the border, smoothed the border by using (DFT + low pass
filter + IDFT)"
which involves quite complicated Matlab coding, yet you ask a question
like this that demonstrates a lack of understanding of pretty basic
Matlab concepts?

Sigh..........
indx is a vector showing the locations of the point before each zero
crossing.

Try this:
t=[0:length(y)-1]';
clf
plot(t,y,t(indx),y(indx),'rx')




From: Manal on 16 Jun 2010 19:49
thanks a lot for your help
I really appreciate your replay

Honestly, I am a beginner in Matlab and image processing
and this is my first time to work with it
this is my graduating project and I am working on this code for a month

thanks a gain and pleas be patient with me
I'll come back if I have questions
First  |  Prev  | 
Pages: 1 2
Prev: Displaying multi-dimensional locations in 2D
Next: Time stamp ruing plots!