[vtkusers] Registering two point clouds using iterative closest point

[Luca Penasa]

Hi everybody, 
I am trying to register two lidar-generated point clouds, using the
vtkIterativeClosestPointTransform Class. maybe i did not understood how
this algorithm works but the results are not what i would like.

Some notes:
- the two clouds are not identical, so only a small part of the two are
in common.
- i start with a first approximation of the needed rigid-body transform,
computed with a set of homologous points given by hand. I apply this
transform as LandmarkTransform before starting the ICP execution.

Output from transform filter appear to be too different from my initial
guess. The two clouds are now completely overlapping.

Does anybody use this class for registration of this kind of data?
Why the ICP force to overlap the two clouds? Appear as the algorithm is
trying to get the maximum overlapping and not the minimum point-to-point
distance.


Thank you

-- 
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Luca Penasa
Student at Geosciences Dpt.
University of Padua (IT)
luca.penasa at email.it
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