[Insight-users] co-occurrence matrix

Wed May 19 19:39:04 EDT 2004

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Sorry to bother you again again. Last time hopefully

I have written a test program to display my co-occurrence values.
I have attached the program.

However, the values only appear on the forward diagonal as in

http://homepage.ntlworld.com/glenn.pierce/co-occur.png

They should appear throughout the image as in the

http://homepage.ntlworld.com/glenn.pierce/result.png

I cant think what the problem is.

When I'm done maybe I we can add this to the Examples under statistics.

Thanks alot

On Tue, 2004-05-18 at 11:17 -0400, Luis Ibanez wrote:

> Hi Glenn,
> 
> You can visualize the 2D histogram by first copying
> its values in an itk::Image.
> 
> For this you can write a while() loop and use the
> method
> 
>        histogram->GetFrequency( index );
> 
> Then you convert this ITK image into a VTK image
> using the filter adaptors in
> 
>     InsightApplications/Auxiliary/vtk
> 
> and plug this vtkImageData into a vtkImageViewer.
> 
> 
> ---
> 
> We didnt' change the actual computation of your
> List of measurement vectors.  More on this in a
> following email...
> 
> 
>   Regards,
> 
> 
>     Luis
> 
> 
> 
> -------------------
> Glenn Pierce wrote:
> 
> > On Sun, 2004-05-16 at 15:11 -0400, Luis Ibanez wrote:
> > 
> >>Hi Glenn,
> >>
> >>Thanks for contributing your code to ITK.
> >>
> >>The class has been added under
> >>
> >>     Insight/Code/Numerics/Statistics.
> >>
> >>
> > 
> > Thanks :)
> > 
> >>
> >>Your VTK question wasn't quite clear.
> >>
> >>Do you want to take a VTK image and get a cooccurrence
> >>matrix out of it using ITK ?
> >>
> >>or, do you want to use VTK for visualizing the
> >>cooccurrence matrix that you computed with ITK ?
> >>
> > 
> > I wanted to visualise the cooccurrence matrix with vtk as a grey scale 
> > image.
> > So I would be visualising  the frequency for each "pair of intensity 
> > values". 
> > So pairs that have a greater frequency appear as higher intensities in a 
> > grey level image.
> > 
> > In my code I was storing each pair in it's own MeasurementVector. 
> > However I should have
> > been increasing the frequency for pairs that are the same. Was this 
> > changed ?
> > 
> > 
> > Thanks for the help.
> > 
> > Much appreciated
> > 
> > 
> > Glenn
> > 
> 
> 
> 

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Sorry to bother you again again. Last time hopefully 
 
I have written a test program to display my co-occurrence values. 
I have attached the program. 
 
However, the values only appear on the forward diagonal as in 
 
<A HREF="http://homepage.ntlworld.com/glenn.pierce/co-occur.png">http://homepage.ntlworld.com/glenn.pierce/co-occur.png</A> 
 
They should appear throughout the image as in the 
 
<A HREF="http://homepage.ntlworld.com/glenn.pierce/result.png">http://homepage.ntlworld.com/glenn.pierce/result.png</A> 
 
I cant think what the problem is. 
 
When I'm done maybe I we can add this to the Examples under statistics. 
 
Thanks alot 
 
 
On Tue, 2004-05-18 at 11:17 -0400, Luis Ibanez wrote:
<BLOCKQUOTE TYPE=CITE>
<PRE>
Hi Glenn,

<FONT COLOR="#000000">You can visualize the 2D histogram by first copying</FONT>
<FONT COLOR="#000000">its values in an itk::Image.</FONT>

<FONT COLOR="#000000">For this you can write a while() loop and use the</FONT>
<FONT COLOR="#000000">method</FONT>

<FONT COLOR="#000000">       histogram-&gt;GetFrequency( index );</FONT>

<FONT COLOR="#000000">Then you convert this ITK image into a VTK image</FONT>
<FONT COLOR="#000000">using the filter adaptors in</FONT>

<FONT COLOR="#000000">    InsightApplications/Auxiliary/vtk</FONT>

<FONT COLOR="#000000">and plug this vtkImageData into a vtkImageViewer.</FONT>

<FONT COLOR="#000000">---</FONT>

We didnt' change the actual computation of your
List of measurement vectors. More on this in a
following email...

<FONT COLOR="#000000">  Regards,</FONT>

<FONT COLOR="#000000">    Luis</FONT>

<FONT COLOR="#000000">-------------------</FONT>
<FONT COLOR="#000000">Glenn Pierce wrote:</FONT>

&gt; On Sun, 2004-05-16 at 15:11 -0400, Luis Ibanez wrote:
&gt; 
&gt;&gt;Hi Glenn,
&gt;&gt;
&gt;&gt;Thanks for contributing your code to ITK.
&gt;&gt;
&gt;&gt;The class has been added under
&gt;&gt;
&gt;&gt; Insight/Code/Numerics/Statistics.
&gt;&gt;
&gt;&gt;
&gt; 
&gt; Thanks :)
&gt; 
&gt;&gt;
&gt;&gt;Your VTK question wasn't quite clear.
&gt;&gt;
&gt;&gt;Do you want to take a VTK image and get a cooccurrence
&gt;&gt;matrix out of it using ITK ?
&gt;&gt;
&gt;&gt;or, do you want to use VTK for visualizing the
&gt;&gt;cooccurrence matrix that you computed with ITK ?
&gt;&gt;
&gt; 
&gt; I wanted to visualise the cooccurrence matrix with vtk as a grey scale 
&gt; image.
&gt; So I would be visualising the frequency for each &quot;pair of intensity 
&gt; values&quot;. 
&gt; So pairs that have a greater frequency appear as higher intensities in a 
&gt; grey level image.
&gt; 
&gt; In my code I was storing each pair in it's own MeasurementVector. 
&gt; However I should have
&gt; been increasing the frequency for pairs that are the same. Was this 
&gt; changed ?
&gt; 
&gt; 
&gt; Thanks for the help.
&gt; 
&gt; Much appreciated
&gt; 
&gt; 
&gt; Glenn
&gt;

</PRE>
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