[Insight-users] about the number of the controlling points of cubic Bspline

[Luis Ibanez]

Hi Yixun,

You are right, the evaluation of a point in a
CubicBSpline requires to use 4^N control points.
Where N is the dimension of space.

That 27 indicated in this document seems to be an
error that slipped through. Thanks for pointing this
out.


BTW, you will find an example on the use of BSplines
for deformable registration in


  Insight/Examples/Registration/
            DeformableRegistration4.cxx


Regards,


   Luis


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

> Hi ITKusers,
>  
> in my opinion, need 16 controlling points to evaluate the deformation at 
> any one position with respect to 2D image. 
>  
> so, need 64 controlling points with respect to 3D image. However, "the 
> medical visualization with ITK" says that 27 controlling points will be 
> enough. Could anybody tell me the reason?
>  
> Best regards,
>  
> Yixun Liu
> 
>