[Insight-users] warping a clound of points when the target landmarks form a straight line

[Nicholas Tustison]

Hi Ramon,

Do you have a one-to-one correspondence between source points and
target points?  If so, you could use the following filter

http://www.itk.org/Doxygen/html/classitk_1_1BSplineScatteredDataPointSetToImageFilter.html

Nick



On Jun 20, 2011, at 6:49 AM, Ramón Casero Cañas wrote:

> 
> Hi,
> 
> I have a cloud of 3D points in space from a sampling of a bent cylinder.
> 
> I would like to straighten up said cylinder.
> 
> I have tried the ITK kernel transforms
> 
>   itk::ElasticBodySplineKernelTransform
>   itk::ElasticBodyReciprocalSplineKernelTransform
>   itk::ThinPlateSplineKernelTransform
>   itk::ThinPlateR2LogRSplineKernelTransform
>   itk::VolumeSplineKernelTransform
> 
> saying that I want to map the curved medial line of the cloud of points (source landmarks) to a straight line (target landmarks).
> 
> However, all kernel transforms suffer from the limitation that they can only map points to the space spanned by the target landmarks.
> 
> That is, if the target landmarks form a straight line, the bent cylinder will be transformed to a straight line, not a straight cylinder.
> 
> Then I looked into using
> 
>   itk::BSplineDeformableTransform
> 
> but it doesn't seem to operate on a sparse set of landmarks, but on a regular mesh.
> 
> 
> I have been searching online, and although there seems to be a cornucopia of methods to deform meshes, I couldn't find anything that seems readily implemented.
> 
> Is there a more or less simple way to solve this problem in ITK?
> 
> Best regards,
> 
> Ramon.
> 
> 
> -- 
> Dr. Ramón Casero Cañas
> 
> Computational Biology
> Department of Computer Science
> University of Oxford
> Wolfson Building, Parks Rd
> Oxford OX1 3QD
> 
> tlf     +44 (0) 1865 610737
> web     http://web.comlab.ox.ac.uk/people/Ramon.CaseroCanas
> photos  http://www.flickr.com/photos/rcasero/
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