[Insight-users] vtk polydata import / export

imho imho at bephp . com
Sat, 12 Jul 2003 09:37:16 +0200


Hi Luis,
thanks a lot for your detailled explanation, I'll try it and I'll tell 
you what I've got. ;-)

Imho.

Luis Ibanez wrote:

>
> Hi Imho,
>
> You may want to use the VTK filter:
>
>            vtkImplicitModeller
>
> http://www . vtk . org/doc/nightly/html/classvtkImplicitModeller . html
>
> This filter accepts as input a vtkPolyData,
> and produces a vtkImageData as output.
>
> The output vtkImageData is computed as a (non-signed)
> distance to the surface represented by the itkPolyData.
>
> Once you get this image you can go different paths:
>
> A) you could use these signed distance images as
>    direct input for the Demon's registration algorithm
>
> or
>
> B) you could threshold both of them a bit over zero and
>    then obtain the inside/outside regions using a
>    connectivity filter (VTK or ITK), for example
> http://www . itk . org/Insight/Doxygen/html/classitk_1_1ConnectedComponentImageFilter . html
>    This will give you binary masks inside the polydata surface.
>
>
> ----
>
>
> The Demons registration algorithm is designed to work on
> images, the itkMesh will not be an appropriate input, so
> the conversion described above will certainly be necesary.
>
>
>
>
>   Regards,
>
>
>      Luis
>
>
> ---------------------
> imho wrote:
>
>> Hi Luis,
>> I try to do what you said, my pipeline is ready and also the demon
>> registration class, and all is compiling, but I don't know how to
>> convert my vtkPolyData to a  vtkImageData. I do a simple CopyStructure
>> but I think it works badly, because I have an execution error.
>> Can I use the demonFilter with an itkMesh ?
>>
>> thanks
>>
>> Imho
>>
>> Luis Ibanez wrote:
>>
>>>
>>> Hi Imho,
>>>
>>> The import/export connections currently available
>>> between ITK and VTK only manage image-to-image
>>> conversions.
>>>
>>> You may want to convert your vtkPolyData to a vtkImageData
>>> and then use the itkVTKImageToImageFilter available in
>>>
>>>    InsightApplications/Auxiliary/vtk
>>>
>>> In any case, a vtkPolyData may not be the best support
>>> for representing an image...
>>>
>>>
>>> Please let us know if you have futher questions,
>>>
>>>
>>> Thanks
>>>
>>>
>>>    Luis
>>>
>>>
>>>
>>> ------------------
>>> imho wrote:
>>>
>>>> Hi all,
>>>> is it possible to import and export a vtkPolyData or can I use 
>>>> images only?
>>>> How can I do?
>>>> I have two vtkPolyData volumes, and I'd like to use itk filters 
>>>> like this :
>>>>
>>>> vtk reader -> vtk filters -> itk filters -> vtk viewer
>>>> I've tried this :
>>>>
>>>> VTK                            ->              
>>>> ITK                    ->              VTK
>>>>
>>>> ITKImageExporter4            VTKImageImporter4            
>>>> ITKImageImporter4        == first POLY
>>>>
>>>> ITKImageExporter5            VTKImageImporter5 
>>>>                                                  == second POLY (no 
>>>> output)
>>>>
>>>> but I don't know how to convert my vtkPolyData or how to typedef 
>>>> the VTKimporter to make it work :
>>>>     typedef unsigned short PixelType;
>>>>     typedef itk::Image<PixelType, Dimension> ImageType;
>>>>     typedef itk::VTKImageImport<ImageType> ImageImportType;
>>>> is ok but not with a polyData, and
>>>>
>>>>     typedef itk::VTKImageImport<vtkPolyData*> ImageImportType;
>>>>  isn't ok
>>>>
>>>> Thanks a lot
>>>>
>>>> imho
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
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>>
>
>
>
> .
>