ITK/Examples/Developer/InplaceImageFilter

This example demonstrates how to write a filter which produces an output image which is equal to the input image except its corner pixel is set to 3. The image that is the input to the filter also has its corner pixel value changed!

InPlaceImageFilterExample.cxx

<source lang="cpp">

1. include "itkImage.h"
2. include "itkImageFileReader.h"
3. include "itkImageFileWriter.h"

1. include "MyInPlaceImageFilter.h"

template <typename TImage> static void CreateImage(TImage* const image);

int main(int, char*[]) {

 // Setup types
 typedef itk::Image<int, 2>   ImageType;
 typedef itk::MyInPlaceImageFilter<ImageType>  FilterType;

 ImageType::Pointer image = ImageType::New();
 CreateImage(image.GetPointer());

 // Create and the filter
 FilterType::Pointer filter = FilterType::New();
 filter->SetInput(image);
 filter->SetInPlace(true);
 filter->Update();

 itk::Index<2> cornerPixel = image->GetLargestPossibleRegion().GetIndex();

 // The output here should be "3"
 std::cout << "Filter output:" << std::endl;
 std::cout << filter->GetOutput()->GetPixel(cornerPixel) << std::endl;

 // The follow calls fail. This is because the output has stolen the input's
 // buffer and the input has no image buffer.

// std::cout << "Image output:" << std::endl; // std::cout << image->GetPixel(cornerPixel) << std::endl;

 return EXIT_SUCCESS;

}

template <typename TImage> void CreateImage(TImage* const image) {

 // Create an image with 2 connected components
 typename TImage::IndexType corner = Template:0,0;

 unsigned int NumRows = 200;
 unsigned int NumCols = 300;
 typename TImage::SizeType size = Template:NumRows, NumCols;

 typename TImage::RegionType region(corner, size);

 image->SetRegions(region);
 image->Allocate();

 image->FillBuffer(0);

}

</source>

MyInPlaceImageFilter.h

<source lang="cpp">

1. ifndef __itkMyInPlaceImageFilter_h
2. define __itkMyInPlaceImageFilter_h

1. include "itkInPlaceImageFilter.h"

namespace itk { template< class TImage> class MyInPlaceImageFilter : public InPlaceImageFilter<TImage> { public:

 /** Standard class typedefs. */
 typedef MyInPlaceImageFilter             Self;
 typedef InPlaceImageFilter<TImage> Superclass;
 typedef SmartPointer< Self >        Pointer;

 /** Method for creation through the object factory. */
 itkNewMacro(Self);

 /** Run-time type information (and related methods). */
 itkTypeMacro(MyInPlaceImageFilter, InPlaceImageFilter);

protected:

 MyInPlaceImageFilter(){}
 ~MyInPlaceImageFilter(){}

 /** Does the real work. */
 virtual void GenerateData();

private:

 MyInPlaceImageFilter(const Self &); //purposely not implemented
 void operator=(const Self &);  //purposely not implemented

}; } //namespace ITK

1. ifndef ITK_MANUAL_INSTANTIATION
2. include "MyInPlaceImageFilter.hxx"
3. endif

1. endif

</source>

MyInPlaceImageFilter.txx

<source lang="cpp">

1. ifndef __itkMyInPlaceImageFilter_hxx
2. define __itkMyInPlaceImageFilter_hxx

1. include "MyInPlaceImageFilter.h"

1. include "itkObjectFactory.h"
2. include "itkImageRegionIterator.h"
3. include "itkImageRegionConstIterator.h"

namespace itk {

template< class TImage> void MyInPlaceImageFilter< TImage>

GenerateData()

{

 typename TImage::ConstPointer input = this->GetInput();
 typename TImage::Pointer output = this->GetOutput();

 // This call must come before the GetRunningInPlace() call or the
 // GetRunningInPlace() will return an incorrect result.
 this->AllocateOutputs();

 if (!this->GetRunningInPlace())
 {
   std::cerr << "The idea of this example is to run inplace, something is wrong!" << std::endl;
   return;
 }

 itk::Index<2> cornerPixel = input->GetLargestPossibleRegion().GetIndex();
 typename TImage::PixelType newValue = 3;
 output->SetPixel( cornerPixel, newValue);

}

}// end namespace

1. endif

</source>

CMakeLists.txt

<syntaxhighlight lang="cmake"> cmake_minimum_required(VERSION 3.9.5)

project(ImageFilter)

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

 find_package(VTK REQUIRED)
 include(${VTK_USE_FILE})

endif()

add_executable(ImageFilter MACOSX_BUNDLE ImageFilter.cxx)

if( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(ImageFilter ITKReview ${ITK_LIBRARIES})

else( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(ImageFilter ${ITK_LIBRARIES})

endif( "${ITK_VERSION_MAJOR}" LESS 4 )

</syntaxhighlight>

Download and Build ImageFilter

Click here to download ImageFilter and its CMakeLists.txt file. Once the tarball ImageFilter.tar has been downloaded and extracted,

cd ImageFilter/build

• If ITK is installed:

cmake ..

• If ITK is not installed but compiled on your system, you will need to specify the path to your ITK build:

cmake -DITK_DIR:PATH=/home/me/itk_build ..

Build the project:

make

and run it:

./ImageFilter

WINDOWS USERS PLEASE NOTE: Be sure to add the ITK bin directory to your path. This will resolve the ITK dll's at run time.

Building All of the Examples

Many of the examples in the ITK Wiki Examples Collection require VTK. You can build all of the the examples by following these instructions. If you are a new VTK user, you may want to try the Superbuild which will build a proper ITK and VTK.

ItkVtkGlue

ITK >= 4

For examples that use QuickView (which depends on VTK), you must have built ITK with Module_ITKVtkGlue=ON.

ITK < 4

Some of the ITK Examples require VTK to display the images. If you download the entire ITK Wiki Examples Collection, the ItkVtkGlue directory will be included and configured. If you wish to just build a few examples, then you will need to download ItkVtkGlue and build it. When you run cmake it will ask you to specify the location of the ItkVtkGlue binary directory.