[Insight-users] co-occurrence matrix
Glenn Pierce
glennpierce@connectfree.co.uk
Fri May 14 16:04:41 EDT 2004
On Fri, 2004-05-14 at 10:17 -0400, Luis Ibanez wrote:
>
> Hi Glenn
>
>
> You don't really need to write much code in order
> to compute a coocurrence matrix in ITK because a
> Coocurrence Matrix is simply a 2D Histogram.
>
> The itk::Statistics::Histogram class has been desigened
> from the beginning for supporting multicomponent data.
> Actually if you look at the Histogram example in the
> SoftwareGuide, it is a 2D histogram case:
>
> http://www.itk.org/ItkSoftwareGuide.pdf
>
> Section 10.1.3, pdf-page 428.
>
> --
>
> You should be fine by just taking your two input images
> and composing a Vector image with them. For this you can
> use the Compose3DVectorImageFilter:
> http://www.itk.org/Insight/Doxygen/html/classCompose2DVectorImageFilter.html
>
Ah I think I must have the wrong terminology, As I am working with only
one grey scale image.
Or maybe I am missing something fundamental.
I was thinking of a grey-level co-occurence matrix.
ie for each pixel in a grey scale image I would record the intensity
level and also the intensity level of one of the adjacent pixels (Can do
this for each of the adjacent pixels). I would then use the two
intensity values as an index in maybe a 2d histogram where I increment
the value at that index.
This can provide information about the regions of the image
(Sorry about the poor explanation)
probably better description at
http://www.engr.panam.edu/ee/faculty/harlow/6399/notes/Ch24.pdf.
Sorry if I have misunderstood.
Thanks for the feedback
>
> Then, passing this vector image to the ImageToHistogramGenerator:
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1Statistics_1_1ImageToHistogramGenerator.html
>
> and you get the 2D histogram at the end, which is exactly
> a Coocurrence Matrix. Note that you must define the bin
> sizes along every dimension, as well as the min and max
> values to cover with the his domain of the histogram.
>
>
>
> The pipeline will look like
>
>
> Image1---+
> |
> V
> Compose2DVectorImage ---> ImageToHistogramGenerator ---> Histogram
> ^
> |
> Image2---+
>
>
>
> Please let us know if you find any problem,
>
>
> Thanks
>
>
>
> Luis
>
>
>
>
> -------------------
> Glenn Pierce wrote:
> > Hi
> >
> > I was wondering what the best way of implementing a co-occurrence
> > matrix.
> > I was thinking of just using itk::Statistics::ImageToListAdaptor or a
> > subclass to loop through the image's
> > pixel values and counting each co-occurrence in a histogram.
> >
> > Would there be a better way for itk, with respect to contributing the
> > code back to ITK?
> > Maybe basing my code on another filter?
> >
> > Thanks
> >
> > Glenn
> >
> >
> > Glenn Pierce
> > email: glennpierce@connectfree.co.uk
> >
> > _______________________________________________
> > Insight-users mailing list
> > Insight-users@itk.org
> > http://www.itk.org/mailman/listinfo/insight-users
> >
>
>
>
Glenn Pierce
email: glennpierce@connectfree.co.uk
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