[Insight-users] itk::octree

[Bill Lorensen]

Luis,

This thread is also related to the kdtree not being thread-safe.

Bill

On Tue, Dec 1, 2009 at 6:29 PM, Luis Ibanez <luis.ibanez at kitware.com> wrote:
> 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.
>> _____________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Kitware offers ITK Training Courses, for more information visit:
>> http://www.kitware.com/products/protraining.html
>>
>> Please keep messages on-topic and check the ITK FAQ at:
>> http://www.itk.org/Wiki/ITK_FAQ
>>
>> Follow this link to subscribe/unsubscribe:
>> http://www.itk.org/mailman/listinfo/insight-users
>>
> _____________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Kitware offers ITK Training Courses, for more information visit:
> http://www.kitware.com/products/protraining.html
>
> Please keep messages on-topic and check the ITK FAQ at:
> http://www.itk.org/Wiki/ITK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.itk.org/mailman/listinfo/insight-users
>