[Insight-users] point cloud registration

[Luis Ibanez]

Hi Wenzeld,

You may want to read the description of this
problem in the ITK Software Guide

    http://www.itk.org/ItkSoftwareGuide.pdf


That describes the ICP examples in Examples/Patented.

ICP is the method that you may want to use in this case.


You are right in your observation that the examples in
this directory do not use any of the classes in the main
Patented directory. The reason is that thanks to the
modularity of the ITK Registration Framework, you can
"build" ICP by putting together ITK components.


In practice,
the recipe for "ICP" includes the
following ingredients:

   1) Sum of Squared Distances Metric
   2) An optimizer (usually Levenberg-Marquardt)
   3) A search for nearest points

Option (3) can be solved implicity with the help of
a distance map, as illustrated in the examples of
the ITK Software Guide.

The "issue" with the ICP examples is that they are using
fairly common algorithmic compontes as the ones listed
above. Individually, they are not patented (as far as we
know), but when you put them together in the particular
combination described in the examples then you have an
equivalent to ICP.

This is just another instance of how shamefully the
intellectual property system obstructs the advancement
of science and technology in the foolish quest for
individual profit, most of the time at the expense of
ideas that are... not that bright.

The US patent office awards patents for "human genes",
as well as for the "peanut-butter and jelly sandwich".

You will find an intersting discussion on intellectual
property in the book:

"The Future of Ideas" by Lawrence Lessig
http://www.amazon.com/exec/obidos/tg/detail/-/0375726446/qid=1122475215/sr=8-1/ref=pd_bbs_sbs_1/104-7198053-7029550?v=glance&s=books&n=507846


BTW, The patent for ICP is held by General Motors.



Regards,


   Luis


------------------------
wenzeld at att.net wrote:
> I am a little familiar with ITK.  I am curious about if, and how, the following can be done using ITK.  (I can read the documentation to understand the details; I just need to know if it is possible and generally which class(es) to use.)
> 
> 1. I have a triangle mesh surface (not closed) and a 3D point cloud of points.  The cloud of points is acquired by a human using an arbitrary traversal across the surface using a Microscribe digitizer.  How can the 3D point cloud be registered to the triangle mesh surface?  I only need to register using rotations, translations, and scale.
> 
> 2. In another scenario, I have two 3D point clouds (and no triangle mesh surface) which I need to register to each other.  These point clouds are acquired at separate points in time (e.g., days apart) and perhaps even by seperate humans using the digitizer which means their scanning patterns may be different.  So, there is no correspondence between points, at least in the order in which they were digitized.  Is the ICP (iterative closest point) algorithm appropriate for this pointset-to-pointset registration?  If not, does one of the point sets have to be converted into a triangle mesh (if so, how is that done)?
> 
> 3. If the ICP algorithm is to be used in response to issue number 2 above, then how is the fact that the ICP example in the "examples/patented" folder need to be addressed?  I did not see that any of the classes in the "code/patented" folder were being used by this example.  So, what issues, if any, are there in using this algorithm?
> 
> Thanks...
> 
> Dennis Wenzel
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