Dear,
MATLAB provides a function for detection of edges..by Laplacian..
Detect edge pixel positions and than you can manipulate to what you want.. first and foremost is that get Matlab and start exploring Image processing tool..
hope this helps.

Hi,

"Identifying Round Objects" in MATLAB demos could be useful for your
application,
You can try it...
Good Luck.

On Wed, Apr 29, 2009 at 8:15 PM, manuj keshari wrote:

> u can use image morphing related operations like image dilation and
> eroding,
> can also try functions bwtraceboundary and bwboundaries, inbuilt in
> MATLAB...
> On Wed, Apr 29, 2009 at 8:22 AM, colenajayi >
> wrote:
>
> > I've a image with a circular object within it. I am interested only in
> the
> > circular object for further analysis. I've tried several approaches to
> get
> > the pixel for that circular object. The first approach executed was to
> > equate every matrix outside the circular object to zero but I had a
> concern,
> > i couldn't zero the edges since my original picture was in square. My
> other
> > approach is trying to write a matlab code that will extract the circular
> > object from the image but I didn't know how.
> >
> > I'll appreciate if anyone can be of help.
> >
> > I look forward to your reply
> >
>
>

--
M. Behravan

Thanks for your mail. My matlab doesn't have these function. Can you advice on another approach? or do I need to activate something in matlab to use this function

I've a image with a circular object within it. I am interested only in the circular object for further analysis. I've tried several approaches to get the pixel for that circular object. The first approach executed was to equate every matrix outside the circular object to zero but I had a concern, i couldn't zero the edges since my original picture was in square. My other approach is trying to write a matlab code that will extract the circular object from the image but I didn't know how.
>
>I'll appreciate if anyone can be of help.
>
>I look forward to your reply

u can use image morphing related operations like image dilation and eroding,
can also try functions bwtraceboundary and bwboundaries, inbuilt in
MATLAB...

On Wed, Apr 29, 2009 at 8:22 AM, colenajayi wrote:

> I've a image with a circular object within it. I am interested only in the
> circular object for further analysis. I've tried several approaches to get
> the pixel for that circular object. The first approach executed was to
> equate every matrix outside the circular object to zero but I had a concern,
> i couldn't zero the edges since my original picture was in square. My other
> approach is trying to write a matlab code that will extract the circular
> object from the image but I didn't know how.
>
> I'll appreciate if anyone can be of help.
>
> I look forward to your reply
>

I've a image with a circular object within it. I am interested only in the circular object for further analysis. I've tried several approaches to get the pixel for that circular object. The first approach executed was to equate every matrix outside the circular object to zero but I had a concern, i couldn't zero the edges since my original picture was in square. My other approach is trying to write a matlab code that will extract the circular object from the image but I didn't know how.

I'll appreciate if anyone can be of help.

I look forward to your reply