[Insight-users] How t oextract a pointer to ITK image data

[Luis Ibanez]

Hi Prename Surname,



        Yes, We have done this before.



You should look at the examples of the VolView Plugins.


They are in the directory:


     InsightApplications/VolviewPlugins


The plugins are built in DLLs and VolView invoke them
to perform processing in the images.



What you must respect is:


    A) Memory allocated in your program
       *MUST NOT* be released by the DLL.


    B) Memory allocated in the DLL
       *MUST NOT* be released by the program



If you are doing the rendering in your DLL, one easy
thing to do is to pass to it the pointer of the pixel
data

            image->GetBufferPointer();


and the metadata of

      a) number of pixels
      b) pixel spacing
      c) image origin

With this information you can in your DLL use the
vtkImageImport filter in order to create a vtkImageData
that you can pass to your rendering pipeline.



         Please read the Tutorials.



The describe things that you have to
do in this case anyways.

In particular, they describe how to prevent
the VTK import filter from releasing the memory
that you passed to it.



     Regards,


        Luis



------------------------
Prename Surname wrote:
> But the problem is that my rendering is in a dll.
> I mean i can convert an ITK image to a vtk image no problem, but the 
> problem is that the vtkimage is to be used in a dll.
> So i am trying to do the following
>  
> ITK -> convert and transfer to DLL -> VTK
>  
> Theoretically it should not pose a problem, but did anyone do this before?
> Regards
> 
>  
> 2006/10/28, Luis Ibanez <luis.ibanez at kitware.com 
> <mailto:luis.ibanez at kitware.com>>:
> 
> 
>     Hi Prename Surname,
> 
>     Please read the Tutorials:
> 
>        http://www.itk.org/HTML/Tutorials.htm
> 
>     In particular:
> 
>        "Getting Started II: Using ITK with VTK"
>     http://www.itk.org/CourseWare/Training/GettingStarted-II.pdf
>     <http://www.itk.org/CourseWare/Training/GettingStarted-II.pdf>
> 
>     and
> 
>        "Getting Started V: Integrating ITK in your Application."
>     http://www.itk.org/CourseWare/Training/GettingStarted-V.pdf
>     <http://www.itk.org/CourseWare/Training/GettingStarted-V.pdf>
> 
> 
>     The first one describes how to convert ITK images into VTK images.
> 
>     You will find examples in the directory:
> 
>           InsightApplications/Auxiliary/vtk/
> 
>     itkReadITKImage3DSegmentShowVTK.cxx
>     itkReadITKImageSegmentShowVTK.cxx
>     itkReadITKImageShowSplineVTK.cxx
>     itkReadITKImageShowVTK.cxx
> 
> 
>     The second one describes multiple options for passing ITK image
>     data to and from applications that use pointers to the pixel
>     buffer.
> 
> 
>     Please not that you must make sure that the memory is relased
>     correctly once you are done with the image.
> 
> 
>        Regards,
> 
> 
>          Luis
> 
> 
>     ----------------------------
>     Prename Surname wrote:
>      > Hello. I have an itk::Image objekt where i want to be able to get a
>      > pointer to the data, so that i can send this pointer as a
>     parameter to
>      > my dll function, which
>      > implements rendering using VTK.
>      >
>      > The only problem is how i can transport the data, and it seems that a
>      > raw datapointer is the best solution.
>      >
>      > How can i retrieve that?
>      > Many regards
>      >
>      >
>      >
>     ------------------------------------------------------------------------
> 
>      >
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>