[Insight-users] Re: need your help : FEM registration for surfaces and clouds of points

[Luis Ibanez]

Hi Yxliu

The FEM framework in ITK is mostly designed for
registering two images. The mesh is used as a suport
for representing the deformation and its physical
model.

What you have sounds more like a PointSet to Surface
registration. In that context you you may rather use
the Iterative Closest Point approach but with a
transform with many degrees of freedom (e.g. more
than the Rigid 3D).


You will find and example on the use of ICP in ITK
under:

   Insight/Examples/Registration/
               IterativeClosestPoint1.cxx
               IterativeClosestPoint2.cxx
               IterativeClosestPoint3.cxx

Note that the Transform can be selected from the
set of ITK transforms. You probably can get
a fairly large amount of deformation with an
AffineTransform first, and then if necessary
continue with a BSplineDeformaleTransform.


The examples above were added after release 1.6.
Therefore you will have to use a CVS version of
ITK in order to find them.


Please let us know if you have further questions.


     Thanks


       Luis



------------
yxliu wrote:

> Hello Luis,
....

>  
> I am doing the research about brain shift. I want to tracking the 
> movement of the cortex. I have two images: one is cortex 
> surface represented by the mesh; the other image is surface represented 
> by point cloud. I do not konw how to registed the first surface to the 
> second. Can the itkfemregistrationfilter help me solve the problem?
>  
> Thank you in advance!
>  
> Best regards
>  
> Yixun liu