[Insight-users] itk::octree

[Luis Ibanez]

Hi motes,

We should reduce your case to a minimal test,
as suggested in my previous email.

Let's try doing that with the tests:

    Testing/Code/Numerics/Statistics/
                        itkKdTreeGeneratorTest.cxx

We just need to get a duplicate of your
process for generating points. (or a file
with the point coordinates).


     Thanks,

          Luis


-----------------------------------
On Sat, Nov 28, 2009 at 12:25 PM, motes motes <mort.motes at gmail.com> wrote:
> On Sat, Nov 28, 2009 at 5:47 PM, David Doria <daviddoria+itk at gmail.com> wrote:
>> On Sat, Nov 28, 2009 at 11:42 AM, motes motes <mort.motes at gmail.com> wrote:
>>>
>>> I am looking at itkOctreeTest.cxx which runs a test on an octree. The
>>> octree is build from a 3D image where each pixel has a value.
>>>
>>> My question is now. Is it possible to use the above octree as
>>> structure to find the k-nn to a point p?
>>>
>>> Assume that we have a 3D image which contains 12*12*12 nodes
>>> distributed randomly in the volume. Now for a given point p in the
>>> volume, the nodes within a specified radius r should be returned.
>>>
>>> As I understand the octree returns values of pixels and not locations
>>> but maybe with some modification it could be possible to convert this
>>> into locations? Does anyone have an idea for this?
>>>
>>
>> My understanding is that typical practice says to use a kdtree for NN
>> searches and an octree for ray intersections (although I've found the
>> modified-BSP tree to be MUCH faster at ray intersections). Can someone
>> verify this?
>>
>> Were you having a problem doing a NN search with the ITK kdtree?
>
>
> Yes but it only happens when using it in a transform in a resampling
> filter. I have tried various techniques (Valgrind, unit-test) to find
> the error but I still have not been able to locate it. I can only
> conclude that doing a seach on a kdTree from  the function
> "TransformPoint" is not a good idea and will cause a segmentation
> fault. But I am still trying to find it.
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