[Insight-users] Thin-plate spline limitations?

[Luis Ibanez]

Hi Steve,

Certainly 2x10^5 landmarks will be too many for the
spline implementation on ITK.  I would guess that
about one thousand landmarks is a reasonable number.

The FMM method is not implemented in ITK. However,
it doesn't seem to be too hard to get it done.


There are a couple of mechanisms for getting this
method (or any other algorithm) into the toolkit.

1) If you volunteer to write the bulk of the code,
    an ITK developer will volunteer to assist you
    in the process.

2) If the code results to require a mayor effort.
    Let's say 4 months. You could submit a proposal
    for funding after the NLM. There is an annual
    round of RFQs for adding algorithms and data to
    ITK. With an upper limit of 100K.

3) If the code results to be faily simple to write,
    you could simply loby in the users-list in order
    to get this method in the "list-of-things-to-add".


Method (1) is probably the one that better fit the
interest of forming a self-sustaining community for
ITK.



Regards,


   Luis



-------------------
Steve Boyd wrote:
> Hello,
> 
> Is there a limitation to the number of landmarks that can be used in the
> thin-plate spline in ITK?  I understand that numerical problems may
> occur if too many landmarks are used, and I believe this is the case in
> the current VTK implementation.  To overcome this problem, there have
> been publications that describe the use of the fast multipole method
> (FMM) for approximations
> (http://www.aranz.com/download/modelling/papers/siggraph01.pdf), but I'm
> not sure if this has been implemented in ITK.  I'd love to use the
> thin-plate splines method, but my needs for the algorithm would require
> 
>>200,000 landmarks.  
> 
> 
> Has the FMM been implemented in ITK's thin-plate splines?
> 
> Sincerely,
> 
> Steve
>