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Topic: connected components in a grey scale image
Replies: 13   Last Post: May 15, 2008 11:01 AM

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 Deo Posts: 50 Registered: 2/13/08
Re: connected components in a grey scale image
Posted: May 15, 2008 8:35 AM

"us " <us@neurol.unizh.ch> wrote in message <g0h8ao\$879
\$1@fred.mathworks.com>...
> "Deo ":
> <SNIP down to different problem...
>

> > 0.009 0.009 0.009
> > ...
> > I like to label the image above like
> > 1 1 1
> > ...

>
> well, this is simply re-indexing a mat with unique
> integers - independent of the values
> now, one of the many solutions
>
> % the data
> m=[
> 0.09 0.09 0.09
> 0.01 8.00 0.07
> 0.01 9.00 0.06
> 9.00 0.01 7.00
> ];
> % the engine
> [mu,mx,mx]=unique(m);
> r=reshape(mx,size(m));
> % the result
> % - note: <mu> contains the unique abs value(s)
> disp([m;nan(1,size(m,2));r]);
> %{
> 0.09 0.09 0.09 % the original mat
> 0.01 8.00 0.07
> 0.01 9.00 0.06
> 9.00 0.01 7.00
> NaN NaN NaN % visual divider
> 4.00 4.00 4.00 % re-indexed mat
> 1.00 6.00 3.00
> 1.00 7.00 2.00
> 7.00 1.00 5.00
> %}
>
> us

This approach would only work in this situation but in a
scenario such as this
0.09 0.09 0.09 0.01
0.01 8.00 0.07 0.01
0.01 9.00 0.06 0.1
0.09 0.01 7.00 0.7

when it is required that the output should look as
CC1 CC1 CC1 CC6
CC2 CC4 CC5 CC6
CC2 CC7 CC8 CC9
CC3 CC2 CC10 CC11
where CC1 - CC11 are the connected components and they can
be any integer. You can see that clusters of same intensity
are labeled differently when they are not connected.
This what I am looking for maybe I did not express myself

Date Subject Author
5/14/08 Deo
5/14/08 us
5/14/08 Deo
5/14/08 us
5/14/08 Deo
5/14/08 us
5/14/08 Deo
5/14/08 ImageAnalyst
5/15/08 Deo
5/15/08 us
5/15/08 Deo
5/15/08 us
5/15/08 Deo
5/14/08 Deo