[Insight-users] FDF Reader

Luis Ibanez luis.ibanez at kitware.com
Mon, 15 Mar 2004 21:30:02 -0500


Hi Glenn,

The ColorWindow and ColorLevel methods allow you
to do "IntensityWindowing" in the visualization.

You typically have two choices:

A) Display the image using the full range of
    intensities of your data type

B) Display the image by stretching the gray levels
    in such a way that the highest intensity in
    your image uses the brighest values on the display.

Whether  you choose (A) or (B), the selection
of ColorLevel should match the middle vale of
the range you want to display, and ColorWindow
should be set to the width of the range of
intensities you want to display.

--

You can flip images by using any of the ITK filters:

FlipImageFilter
http://www.itk.org/Insight/Doxygen/html/classitk_1_1FlipImageFilter.html

OrientImageFilter
http://www.itk.org/Insight/Doxygen/html/classitk_1_1OrientImageFilter.html\

PermuteAxisImageFilter
http://www.itk.org/Insight/Doxygen/html/classitk_1_1PermuteAxesImageFilter.html

Be very careful with these filters since it is quite
easy to invert the patient's left-right on the display,
and end up operating in the wrong leg...



  Regards,



      Luis



----------------------
Glenn Pierce wrote:

> Hi I have finally gotten a basic FDFImageIO reader.
> I have also written a factory for the reader.
> 
> The code can be download at
> http://homepage.ntlworld.com/glenn.pierce/software/itkFDFImageIO.tar.gz
> 
> This code reads Varian FDF files used often with MRI data.
> Hopefully other itk users can use this.
> 
> I just have a couple of questions.
> The intensities do no display correctly. I am displaying with the 
> vtkImageViewer and when
> setting the following
> 
> viewer->SetColorWindow(1);
> viewer->SetColorLevel(0.1);
> 
> I can just see a slight outline.
> 
> with
> 
> viewer->SetColorWindow(255);
> viewer->SetColorLevel(128);
> 
> Just black displays.
> 
> How do I display the the image with it's intended intensities ?
> At the moment I have normalised the data before displaying the image.
> 
> Also as the image is flipped about both axis how do I flip the image back ?
> 
> Thanks for the help.
> 
> 
> ___________________________________________
> *
> Glenn Pierce*
> 
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> ___________________________________________
> 
> 
> 
>