ITK/Examples/Developer/ImageFilterMultipleOutputs

ImageFilterMultipleOutputsExample.cxx

<source lang="cpp">

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

1. include "ImageFilterMultipleOutputs.h"

int main(int, char*[]) {

 // Setup types
 typedef itk::Image<unsigned char, 2>   ImageType;
 typedef itk::ImageFilterMultipleOutputs<ImageType>  FilterType;

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

 {
 typedef  itk::ImageFileWriter< ImageType  > WriterType;
 WriterType::Pointer writer = WriterType::New();
 writer->SetFileName("TestOutput1.jpg");
 writer->SetInput(filter->GetOutput1());
 writer->Update();
 }
 
 {
 typedef  itk::ImageFileWriter< ImageType  > WriterType;
 WriterType::Pointer writer = WriterType::New();
 writer->SetFileName("TestOutput2.jpg");
 writer->SetInput(filter->GetOutput2());
 writer->Update();
 }
 
 return EXIT_SUCCESS;

} </source>

ImageFilterMultipleOutputs.h

<source lang="cpp">

1. ifndef __itkImageFilterMultipleOutputs_h
2. define __itkImageFilterMultipleOutputs_h

1. include "itkImageToImageFilter.h"

namespace itk { template< class TImage> class ImageFilterMultipleOutputs : public ImageToImageFilter< TImage, TImage > { public:

 /** Standard class typedefs. */
 typedef ImageFilterMultipleOutputs             Self;
 typedef ImageToImageFilter< TImage, TImage > Superclass;
 typedef SmartPointer< Self >        Pointer;

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

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

 TImage* GetOutput1();
 TImage* GetOutput2();
 

protected:

 ImageFilterMultipleOutputs();
 ~ImageFilterMultipleOutputs(){}

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

 /**  Create the Output */
 DataObject::Pointer MakeOutput(unsigned int idx);

private:

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

}; } //namespace ITK

1. ifndef ITK_MANUAL_INSTANTIATION
2. include "ImageFilterMultipleOutputs.txx"
3. endif

1. endif // __itkImageFilterMultipleOutputs_h

</source>

ImageFilterMultipleOutputs.txx

<source lang="cpp">

1. ifndef __itkImageFilterMultipleOutputs_txx
2. define __itkImageFilterMultipleOutputs_txx

1. include "ImageFilterMultipleOutputs.h"

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

namespace itk {

template< class TImage> ImageFilterMultipleOutputs<TImage>::ImageFilterMultipleOutputs() {

 this->SetNumberOfRequiredOutputs(2);
 this->SetNumberOfRequiredInputs(0);

 this->SetNthOutput( 0, this->MakeOutput(0) );
 this->SetNthOutput( 1, this->MakeOutput(1) );

}

template< class TImage> void ImageFilterMultipleOutputs<TImage>::GenerateData() {

 typename TImage::IndexType start;
 start[0] = 0;
 start[1] = 0;

 typename TImage::SizeType size;
 size[0] = 20;
 size[1] = 20;

 typename TImage::RegionType region;
 region.SetSize(size);
 region.SetIndex(start);
 
 // Setup output 1
 typename TImage::Pointer output1 = this->GetOutput1();
 output1->SetRegions(region);
 output1->Allocate();  
 
 itk::ImageRegionIterator<TImage> outputIterator1(output1, output1->GetLargestPossibleRegion());
 outputIterator1.GoToBegin();
 
 while(!outputIterator1.IsAtEnd())
   {
   if(outputIterator1.GetIndex()[0] == outputIterator1.GetIndex()[1])
     {
     outputIterator1.Set(255);
     }
   else
     {
     outputIterator1.Set(0);
     }

   ++outputIterator1;
   }

 // Setup output 2
 typename TImage::Pointer output2 = this->GetOutput2();
 output2->SetRegions(region);
 output2->Allocate();

 itk::ImageRegionIterator<TImage> outputIterator2(output2, output2->GetLargestPossibleRegion());
 outputIterator2.GoToBegin();

 while(!outputIterator2.IsAtEnd())
   {
   if(outputIterator2.GetIndex()[0] > 10)
     {
     outputIterator2.Set(255);
     }
   else
     {
     outputIterator2.Set(0);
     }

   ++outputIterator2;
   }

}

template< class TImage> DataObject::Pointer ImageFilterMultipleOutputs<TImage>::MakeOutput(unsigned int idx) {

 DataObject::Pointer output;

 switch ( idx )
   {
   case 0:
     output = ( TImage::New() ).GetPointer();
     break;
   case 1:
     output = ( TImage::New() ).GetPointer();
     break;
   default:
     std::cerr << "No output " << idx << std::endl;
     output = NULL;
     break;
   }
 return output.GetPointer();

}

template< class TImage> TImage* ImageFilterMultipleOutputs<TImage>::GetOutput1() {

 return dynamic_cast< TImage * >(
          this->ProcessObject::GetOutput(0) );

}

template< class TImage> TImage* ImageFilterMultipleOutputs<TImage>::GetOutput2() {

 return dynamic_cast< TImage * >(
          this->ProcessObject::GetOutput(1) );

}

}// end namespace

1. endif

</source>

CMakeLists.txt

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

project(ImageFilterMultipleOutputsExample)

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

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

endif()

add_executable(ImageFilterMultipleOutputsExample MACOSX_BUNDLE ImageFilterMultipleOutputsExample.cxx)

if( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(ImageFilterMultipleOutputsExample ITKReview ${ITK_LIBRARIES})

else( "${ITK_VERSION_MAJOR}" LESS 4 )

 target_link_libraries(ImageFilterMultipleOutputsExample ${ITK_LIBRARIES})

endif( "${ITK_VERSION_MAJOR}" LESS 4 )

</syntaxhighlight>

Download and Build ImageFilterMultipleOutputsExample

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

cd ImageFilterMultipleOutputsExample/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:

./ImageFilterMultipleOutputsExample

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.