View source for ITK/Using ITK from .NET

This page describes how to use ITK from .NET.
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'''NOTE: You must build ITK, wrapper DLL, and .NET exe all using the same target platform i.e. Win32/x86 or Win64/x64'''
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<li>
Download [http://www.cmake.org/cmake/resources/software.html CMake], [http://www.itk.org/ITK/resources/software.html ITK source code], and [http://www.swig.org/download.html SWIG]
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Build ITK (see [http://www.itk.org/ITK/help/tutorials.html here] for help)
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Create the following <code style="font-size: medium">CMakeLists.txt</code> file:
<div style="background: white; border: 1px dashed rgb(100, 100, 100); padding: 5px; margin: 10px 0px 10px 0px; font-size: medium">
<syntaxhighlight lang="make">
# File: CMakeLists.txt
cmake_minimum_required(VERSION 2.8)

project(ExampleWrapper)

find_package(ITK REQUIRED)
include(${ITK_USE_FILE})

add_library(ExampleWrapper SHARED example.h example.hxx example_wrap.cxx)
target_link_libraries(ExampleWrapper ${ITK_LIBRARIES})
</syntaxhighlight>
</div>
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Create the following <code style="font-size: medium">example.h</code> file:
<div style="background: white; border: 1px dashed rgb(100, 100, 100); padding: 5px; margin: 10px 0px 10px 0px; font-size: medium">
<syntaxhighlight lang="cpp">
// File : example.h
#ifndef __example_h
#define __example_h

#include <string>

template<class TPixel, unsigned int VDimension>
void SmoothImage(
    const std::string input, const std::string output, const double sigma
);

#include "example.hxx"

#endif // __example_h
</syntaxhighlight>
</div>
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Create the following <code style="font-size: medium">example.hxx</code> file:
<div style="background: white; border: 1px dashed rgb(100, 100, 100); padding: 5px; margin: 10px 0px 10px 0px; font-size: medium">
<syntaxhighlight lang="cpp">
#ifndef __example_hxx
#define __example_hxx

#include "example.h"

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkSmoothingRecursiveGaussianImageFilter.h"

template<class TPixel, unsigned int VDimension>
void SmoothImage(
    const std::string input, const std::string output, const double sigma
) {
    // Read input
    typedef itk::Image<TPixel,VDimension> ImageType;
    typedef itk::ImageFileReader<ImageType> ReaderType;
    ReaderType::Pointer reader = ReaderType::New();
    reader->SetFileName(input);
    reader->Update();

    // Apply filter
    typedef itk::SmoothingRecursiveGaussianImageFilter<ImageType> FilterType;
    FilterType::Pointer filter = FilterType::New();
    filter->SetInput(reader->GetOutput());
    filter->SetSigma(sigma);
    filter->Update();

    // Write output
    typedef itk::ImageFileWriter<ImageType> WriterType;
    WriterType::Pointer writer = WriterType::New();
    writer->SetInput(filter->GetOutput());
    writer->SetFileName(output);
    writer->Update();
}

#endif // __example_hxx
</syntaxhighlight>
</div>
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Create the following <code style="font-size: medium">example.i</code> file (instructs SWIG how to generate the wrapper):
<div style="background: white; border: 1px dashed rgb(100, 100, 100); padding: 5px; margin: 10px 0px 10px 0px; font-size: medium">
<syntaxhighlight lang="cpp">
// File : example.i
%module example
%include "std_string.i"

%{
#include "example.h"
%}

%include "example.h"

%template(SmoothImageUC2)SmoothImage<unsigned char, 2>;
%template(SmoothImageF2) SmoothImage<float, 2>;
</syntaxhighlight>
</div>
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Run SWIG using the following command: <code style="font-size: medium">swig -c++ -csharp -dllimport ExampleWrapper example.i</code>
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The following files should be generated:
* <code style="font-size: medium">example_wrap.cxx</code>
* <code style="font-size: medium">example.cs</code>
* <code style="font-size: medium">examplePINVOKE.cs</code>
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Run CMake, configure and generate, build the project. The result should be <code style="font-size: medium">ExampleWrapper.dll</code>
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Create the following C# <code style="font-size: medium">runme.cs</code> file:
<div style="background: white; border: 1px dashed rgb(100, 100, 100); padding: 5px; margin: 10px 0px 10px 0px; font-size: medium">
<syntaxhighlight lang="csharp">
// File: runme.cs
using System;

public class runme {
    [STAThread()]
    static void Main() {
        try {
            example.SmoothImageUC2(
                input: "C:/Temp/cthead1.png",
                output: "C:/Temp/cthead1-smooth.png",
                sigma: 5.0
            );
        } catch (Exception ex) {
            Console.WriteLine(ex);
        }
    }
}
</syntaxhighlight>
</div>
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Build the .NET executable. For Mono use the following: <code style="font-size: medium">mcs -platform:x86 -target:exe -out:example.exe runme.cs example.cs examplePINVOKE.cs</code>
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Run the .NET executable. Make sure it can find <code style="font-size: medium">ExampleWrapper.dll</code> (the easiest way is to copy the dll to the same folder as <code style="font-size: medium">example.exe</code>)
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