[Insight-users] More than one seed point in itk::FastMarchingImageFilter

[Mr Francesco Grussu]

Oh yes, you are write, I was overwriting the two seed points.
I had to change the seed Id.

Many thanks Guido,

Francesco

> Hi Francesco,
>
> I would recommend changing the id of the second seed; that is,
> seeds->Initialize();
> seeds->InsertElement( 0, node1 );
> seeds->InsertElement( 1, node2 );    // instead of:
> seeds->InsertElement( 0, node2 );
>
> It looks like you were replacing node1 with node2.
> Sincerely,
> Guido
>
>
> On Tue, Jun 12, 2012 at 6:00 AM, Mr Francesco Grussu
> <francesco.grussu at eecs.qmul.ac.uk> wrote:
>> Dear all,
>> I am trying to modify the FastMarchingImageFilter.cxx from the ITK Guide
>> in order to use more than one seed point with a Fast Marching
>> segmentation
>> filter from itk::FastMarchingImageFilter .
>>
>> I suppose that I have to pass these seed points as Node containers
>> (FastMarchingFilterType::NodeContainer) but I cannot understand how to
>> do
>> it exactly. Should I call the InsertElement() method of the
>> FastMarchingFilterType::NodeContainer object (via a its smart pointer)
>> more than once? To use more than one seed point, I thought to write
>> something like that:
>>
>> ******************
>>
>>  typedef FastMarchingFilterType::NodeContainer           NodeContainer;
>>  NodeContainer::Pointer seeds = NodeContainer::New();
>>
>>  InternalImageType::IndexType  seedPosition1;
>>  seedPosition1[0] = SEED1X; // a macro previously defined
>>  seedPosition1[1] = SEED1Y; // a macro previously defined
>>
>>  InternalImageType::IndexType  seedPosition2;
>>  seedPosition2[0] = SEED2X; // a macro previously defined
>>  seedPosition2[1] = SEED2Y; // a macro previously defined
>>
>>  const double seedValue = 0.0;
>>
>>  typedef FastMarchingFilterType::NodeType                NodeType;
>>
>>  NodeType node1;
>>  node1.SetValue( seedValue );
>>  node1.SetIndex( seedPosition1 );
>>
>>  NodeType node2;
>>  node2.SetValue( seedValue );
>>  node2.SetIndex( seedPosition2 );
>>
>>  seeds->Initialize();
>>  seeds->InsertElement( 0, node1 );
>>  seeds->InsertElement( 0, node2 );
>>
>> ******************
>>
>> However, the segmentation I get is the same as if I had used just the
>> second seed point (with node2). node1 seems to be completely ignored by
>> the Fast Marching Filter.
>> Do you have any suggestions?
>>
>> Thanks a lot,
>> regards
>>
>> --Francesco
>>
>> _____________________________________
>> 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.php
>>
>> 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.php
>
> 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
>