[Insight-users] Landmark Fitting

[Xenios Papademetris]

Luis,

Thanks for the response. I think you misunderstood my question (probably 
my fault), so let me try again:

Given a point set A and a corresponding point set B (let's arbitrarily 
assume each set has N points) are there methods in ITK for

1. Fitting the best affine transformation between A and B (c.f. 
vtkLandmarkTransform in vtk)

2. Fitting the best spline transform with M (M not equal to N) control 
points using the point sets A and B.

The methods that are in ITK seem to primarily do interpolation, I guess 
our interest is more in terms of approximating the correspondences with 
a more compact (or generic) transformation.

We are in the process of designing an implementation of a set of robust 
point-based matching (RPM) registration algorithms in ITK that came out 
of work done earlier at Yale by Chui, Rangaranjan and collaborators over 
the last 7-8 years. These can be seen as a generalization of the 
Iterative Closest Point algorithm (ICP) -- indeed with a specific choice 
of parameters RPM reduces to ICP.

Thanks again,

Xenios

> 
> ITK offers a good set of point-based transformations.
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1ThinPlateSplineKernelTransform.html 
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1ThinPlateR2LogRSplineKernelTransform.html 
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1ElasticBodyReciprocalSplineKernelTransform.html 
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1ElasticBodySplineKernelTransform.html 
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1VolumeSplineKernelTransform.html 
> 
> All of them require the user to provide two set of landmarks (points).
>  From both sets, a SplineKernel interpolation is perfomed.
> 
> 





-- 
______________________________________________________________________
Xenios Papademetris		     papad@noodle.med.yale.edu
Associate Research Scientist         http://noodle.med.yale.edu/~papad
Image Processing and Analysis Group, Yale University tel: 203-785-7294
______________________________________________________________________