ITK/Examples/Registration/LandmarkBasedTransformInitializer

LandmarkBasedTransformInitializer.cxx

<source lang="cpp">

1. include "itkImageFileReader.h"
2. include "itkImageFileWriter.h"
3. include "itkImage.h"
4. include "itkVector.h"
5. include "itkResampleImageFilter.h"
6. include "itkLandmarkBasedTransformInitializer.h"
7. include "itkRigid2DTransform.h"

const unsigned int Dimension = 2; typedef unsigned char PixelType; typedef itk::Image< PixelType, Dimension > ImageType;

static void CreateFixedImage(ImageType::Pointer image); static void CreateMovingImage(ImageType::Pointer image);

int main(int argc, char * argv[]) {

 typedef   float          VectorComponentType;

 typedef   itk::Vector< VectorComponentType, Dimension >    VectorType;
 typedef   itk::Image< VectorType,  Dimension >   DeformationFieldType;

 ImageType::Pointer fixedImage = ImageType::New();
 CreateFixedImage(fixedImage);
 
 ImageType::Pointer movingImage = ImageType::New();
 CreateMovingImage(movingImage);

 typedef itk::Rigid2DTransform< double > Rigid2DTransformType;
 typedef itk::LandmarkBasedTransformInitializer< Rigid2DTransformType, ImageType, ImageType > 
     LandmarkBasedTransformInitializerType;
     
 LandmarkBasedTransformInitializerType::Pointer landmarkBasedTransformInitializer =
   LandmarkBasedTransformInitializerType::New();
 //  Create source and target landmarks.
 typedef LandmarkBasedTransformInitializerType::LandmarkPointContainer     LandmarkContainerType;
 typedef LandmarkBasedTransformInitializerType::LandmarkPointType          LandmarkPointType;

 LandmarkContainerType fixedLandmarks;
 LandmarkContainerType movingLandmarks;

 LandmarkPointType fixedPoint;
 LandmarkPointType movingPoint;

 fixedPoint[0] = 10;
 fixedPoint[1] = 10;
 movingPoint[0] = 50;
 movingPoint[1] = 50;
 fixedLandmarks.push_back(fixedPoint );
 movingLandmarks.push_back(movingPoint );

 fixedPoint[0] = 10;
 fixedPoint[1] = 20;
 movingPoint[0] = 50;
 movingPoint[1] = 60;
 fixedLandmarks.push_back( fixedPoint );
 movingLandmarks.push_back( movingPoint );

 fixedPoint[0] = 20;
 fixedPoint[1] = 10;
 movingPoint[0] = 60;
 movingPoint[1] = 50;
 fixedLandmarks.push_back(fixedPoint );
 movingLandmarks.push_back(movingPoint );

 fixedPoint[0] = 20;
 fixedPoint[1] = 20;
 movingPoint[0] = 60;
 movingPoint[1] = 60;
 fixedLandmarks.push_back( fixedPoint );
 movingLandmarks.push_back(movingPoint );

 landmarkBasedTransformInitializer->SetFixedLandmarks( fixedLandmarks);
 landmarkBasedTransformInitializer->SetMovingLandmarks( movingLandmarks);
 
 Rigid2DTransformType::Pointer transform = Rigid2DTransformType::New();
 
 transform->SetIdentity();
 landmarkBasedTransformInitializer->SetTransform(transform);
 landmarkBasedTransformInitializer->InitializeTransform();
 
 typedef itk::ResampleImageFilter<ImageType, ImageType, double >    ResampleFilterType;
 ResampleFilterType::Pointer resampleFilter = ResampleFilterType::New();
 resampleFilter->SetInput( movingImage );
 resampleFilter->SetTransform( transform );
 resampleFilter->SetSize( fixedImage->GetLargestPossibleRegion().GetSize() );
 resampleFilter->SetOutputOrigin(  fixedImage->GetOrigin() );
 resampleFilter->SetOutputSpacing( fixedImage->GetSpacing() );
 resampleFilter->SetOutputDirection( fixedImage->GetDirection() );
 resampleFilter->SetDefaultPixelValue( 200 );
 resampleFilter->GetOutput();

 // Write the output
 typedef itk::ImageFileWriter<  ImageType  > WriterType;
 WriterType::Pointer writer = WriterType::New();
 writer->SetInput (  resampleFilter->GetOutput() );
 writer->SetFileName( "output.png" );
 writer->Update();
 
 return EXIT_SUCCESS;

}

void CreateFixedImage(ImageType::Pointer image) {

 // Create a black image with a white square
 ImageType::IndexType start;
 start.Fill(0);

 ImageType::SizeType size;
 size.Fill(100);

 ImageType::RegionType region;
 region.SetSize(size);
 region.SetIndex(start);

 image->SetRegions(region);
 image->Allocate();
 image->FillBuffer(0);

 itk::ImageRegionIterator<ImageType> imageIterator(image,region);

 while(!imageIterator.IsAtEnd())
   {
   if(imageIterator.GetIndex()[0] > 10 && imageIterator.GetIndex()[0] < 20 &&
     imageIterator.GetIndex()[1] > 10 && imageIterator.GetIndex()[1] < 20)
     {
     imageIterator.Set(255);
     }
   ++imageIterator;
   }

 // Write the deformation field
 typedef itk::ImageFileWriter<  ImageType  > WriterType;
 WriterType::Pointer writer = WriterType::New();
 writer->SetInput (  image );
 writer->SetFileName( "fixed.png" );
 writer->Update();

}

void CreateMovingImage(ImageType::Pointer image) {

 // Create a black image with a white square
 ImageType::IndexType start;
 start.Fill(0);

 ImageType::SizeType size;
 size.Fill(100);

 ImageType::RegionType region;
 region.SetSize(size);
 region.SetIndex(start);

 image->SetRegions(region);
 image->Allocate();
 image->FillBuffer(0);

 itk::ImageRegionIterator<ImageType> imageIterator(image,region);

 while(!imageIterator.IsAtEnd())
   {
   if(imageIterator.GetIndex()[0] > 50 && imageIterator.GetIndex()[0] < 60 &&
     imageIterator.GetIndex()[1] > 50 && imageIterator.GetIndex()[1] < 60)
     {
     imageIterator.Set(100);
     }
   ++imageIterator;
   }

 // Write the deformation field
 typedef itk::ImageFileWriter<  ImageType  > WriterType;
 WriterType::Pointer writer = WriterType::New();
 writer->SetInput (  image );
 writer->SetFileName( "moving.png" );
 writer->Update();

}

</source>

CMakeLists.txt

<source lang="cmake"> cmake_minimum_required(VERSION 2.6)

PROJECT(LandmarkBasedTransformInitializer)

FIND_PACKAGE(ITK REQUIRED) INCLUDE(${ITK_USE_FILE})

ADD_EXECUTABLE(LandmarkBasedTransformInitializer LandmarkBasedTransformInitializer.cxx) TARGET_LINK_LIBRARIES(LandmarkBasedTransformInitializer ${ITK_LIBRARIES}) </source>