[Insight-users] Point Set Registration Question

[Mathieu Coursolle]

Hi ITK users,

I'd like to perform a point set registration to compute the affine  
transform that maps from a 2D coordinate system to another.

In the past, I used itk::LandmarkBasedTransformInitializer which works  
fine for rigid transforms. However, I now need a scaling factor
for each dimension.

In chapter 8 of the ITK user guide (p.480 in ITK 2.4 book), it is  
said: "The first case can be solved with a closed form solution when  
we are dealing with a Rigid or an Affine Transform."
According to the doxygen, only rigid transforms are supported for that  
initialiser (http://www.itk.org/Doxygen/html/classitk_1_1LandmarkBasedTransformInitializer.html 
).

What would be the best way to perform a point set registration using 3  
points or more in a 2D space, knowing the pairs of points?

Thanks!

Mathieu