[Insight-users] Re: about pointset registration

[Luis Ibanez]

Hi Yixun,


1) Yes, you can use any ITK Transform for registring
   Point Sets.


2) When you say "very very slow" what do you mean ?
   minutes ? hours ?

   Please be more specific.

   Also: did you compiled your code for "Release" ?
   the difference in performance between Debug and Release
   can easily be a ratio of 10:1


3) The BSpline transform is computationally demanding.
   You should first use an Affine transform in order to align
   the two point sets, then use the resulting Affine transform
   as the "Bulk" transform in the Bspline deformable transform,
   and refine the registration.


4) Iterative closest point tends to take long time when you
   use it as a N x M problem.  You may want to use the option
   of generating a Distance map from one of the point sets
   first, as illustrated in the Examples in the directory

                     Examples/Patented

   Ahh... by the way... the Iterative Closest Point algorithm
   is patented. You need a license from General Motors in order
   to use this algorithm, whether you are in a commercial or
   academic institutions (academic institutions are not exempted
   from Patent laws).



   SOFTWARE PATENTS AND ALGORITHM PATENTS ARE DETRIMENTAL FOR
   THE PROGRESS OF SCIENCE AND TECHNOLOGY. PLEASE HELP TO VOTE
   AGAINST SOFTWARE PATENTS

   For more information look at:

                       http://lpf.ai.mit.edu/

           http://en.wikipedia.org/wiki/Software_patent



   Regards,



      Luis



-----------------
Yixun Liu wrote:
> Hi,
> I need to register two pointsets. Each of them has about 
> 1000 points. The transform is Bspline. The control points is 9X9X5, the 
> spacing is 3X4X4. The Metric is IterativeClosestPointMetric. The 
> Optimizer is LevenbergMarquardtOptimizer. I only set the number of 
> interation to 1. However, the registration runs very very slowly. This 
>  may be caused by optimizer. Which optimizer should I use? Does ITK 
> suppor the non-rigid pointset registration?
>  
> Regards,
>  
> Yixun Liu