[Insight-users] Wrapping a custom C++ function in Python

[Gaëtan Lehmann]

Le 8 juin 09 à 15:12, Julien Lamy a écrit :

> Hi list,

Hi,

>
> I'm trying to wrap a simple C++ function in Python using WrapITK,  
> but the Python script fails with the following traceback :
> TypeError: in method 'test_wrapper', argument 1 of type 'itk::Image<  
> unsigned short,3 > *'
>
> WrapITK otherwise works fine (thank you for those wrappers :) )

you're welcome :-)

>
>
> My C++ function is :
>
>    bool test_wrapper(itk::Image<unsigned short, 3>::Pointer input)
>    {
>        std::cout << input->GetRequestedRegion().GetSize() <<  
> std::endl;
>    }
>
> My Python script is :
>    import numpy
>    import itk
>    from Wrapper import test_wrapper
>
>    data = numpy.arange(3*5*7, dtype=numpy.uint16).reshape((3,5,7))
>    image_itk = itk.PyBuffer[itk.Image[itk.US,  
> 3]].GetImageFromArray(data)
>    test_wrapper(image_itk)
>
> My SWIG wrapper is :
>
>    %module Wrapper
>    %{
>    #include "test_Wrapper.hpp"
>    %}
>
>    bool test_wrapper(itk::Image<unsigned short, 3> * input);

this last line should be

   bool test_wrapper(itkImageUS3 * input);

and you have to #include Base.includes (located at /usr/local/lib/ 
InsightToolkit/WrapITK/Configuration/Typedefs/Base.includes on my  
system), to %include wrap_itkImage.i (/usr/local/lib/InsightToolkit/ 
WrapITK/Configuration/Typedefs/wrap_itkImage.i).
I'm not sure, because that's a function and wrapitk currently only  
wrap classes, but it may be easier to do that with a wrapitk external  
project.

Note that those names are not good enough and will change in a future  
release - hopefully soon - to remove the useless wrap_ prefix, to  
use .h instead of .includes, and to add a prefix to have something  
less common than Base.h. Those changes shouldn't require any changes  
in the sources if the wrapitk external projects are used.

Gaëtan


>
>
> Is there a specific module I should add to the SWIG wrapper ? I'm  
> using ITK 3.14, SWIG 1.3.35, gcc 4.3.2, and Python 2.5.2.
>
> Thanks in advance,
> -- 
> Julien Lamy
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-- 
Gaëtan Lehmann
Biologie du Développement et de la Reproduction
INRA de Jouy-en-Josas (France)
tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
http://voxel.jouy.inra.fr  http://www.itk.org
http://www.mandriva.org  http://www.bepo.fr

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