[Insight-users] How to visualize itk vector fields via ParaView properly?

[Karthik Krishnan]

Hi Ralf,

You need to use Filter->Calculator to convert your 2 component dataset 
to a 3D vector field to be able to glyph it.

See http://public.kitware.com/pipermail/insight-users/2006-April/017464.html

After you do that, you should be able to use the Glyph filter  and the 
Vector / Scale Modes should be available to you.

Hope this helps.
-karthik

Floca, Ralf wrote:
> Hi
>
> I have generated itk images with itk::vector as pixel type (e.g. the
> return of itk::fem::FEMRegistrationFilter<>::GetDeformationField())
>
> Afterwards I have saved these deformation fields as a meta images
> (*.mhd). For saving the images I used similar code snippets like in
> chapter 7.8 of the itkSoftwareGuide 2.2.0.
>
> When I load one of these meta images (2D image with 2D vectors) into
> ParaView, it shows the norm of vectors. The components of the vector
> seems to be available and correct, because in the "Edit Color Map" menu
> it has been recognized as vector and I can choose to show single
> components of the vector instate of the norm.
>
> Now I want to visualize the vectors with a glyph filter. When I add the
> glyph filter directly to the reader, the only available orient mode is
> "Off", "Vector" is disabled and for "Scale Mode" there is only "Data
> Scaling Off" available. As a result of this, I only have unsigned glyphs
> instate of glyphs showing the deformation field.
>
> The information given in a post with a similar topic
> (http://public.kitware.com/pipermail/paraview/2004-February/000478.html)
> didn't helped me, because I think I did everything as explained, but
> wasn't able to properly setup the glyph filter.
>
> I would be very thankful, if anybody could give me a clue what I did
> wrong.
>
> The header of a sample meta image is:
>
> ObjectType = Image
> NDims = 2
> BinaryData = True
> BinaryDataByteOrderMSB = False
> TransformMatrix = 1 0 0 1
> Offset = 0 0
> CenterOfRotation = 0 0
> ElementSpacing = 1 1
> DimSize = 20 20
> AnatomicalOrientation = ??
> ElementNumberOfChannels = 2
> ElementType = MET_DOUBLE
> ElementDataFile = sample.raw
>
> Best regards,
>
> Ralf o Floca
>
> ---------------------------------------------------------------------
> Ralf Floca
> University of Heidelberg                           
> Institute for Medical Biometry and Informatics
> Department of Medical Informatics
> Im Neuenheimer Feld 400            
> D-69120 Heidelberg, Germany             Tel. : +49 (0)6221 56-7484  
> http://www.med.uni-heidelberg.de/mi     Fax  :               -4997    
> ralf.floca at med.uni-heidelberg.de        Sekr.:               -7483
> --------------------------------------------------------------------- 
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