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

[Floca, Ralf]

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

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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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