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/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
// Software Guide : BeginLatex
//
// The following example illustrates how to use the
// \doxygen{BSplineInterpolateImageFunction} for resampling an image. In this
// particular case an \doxygen{AffineTransform} is used to map the input space
// into the output space.
//
// \index{itk::AffineTransform!resampling}
//
// Software Guide : EndLatex
#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkResampleImageFilter.h"
#include "itkBSplineInterpolateImageFunction.h"
// Software Guide : BeginLatex
//
// The header of the affine transform is included below.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
#include "itkAffineTransform.h"
// Software Guide : EndCodeSnippet
int main( int argc, char * argv[] )
{
if( argc < 4 )
{
std::cerr << "Usage: " << std::endl;
std::cerr << argv[0] << " inputImageFile outputImageFile degrees" << std::endl;
return EXIT_FAILURE;
}
const unsigned int Dimension = 2;
typedef unsigned char InputPixelType;
typedef unsigned char OutputPixelType;
typedef itk::Image< InputPixelType, Dimension > InputImageType;
typedef itk::Image< OutputPixelType, Dimension > OutputImageType;
typedef itk::ImageFileReader< InputImageType > ReaderType;
typedef itk::ImageFileWriter< OutputImageType > WriterType;
ReaderType::Pointer reader = ReaderType::New();
WriterType::Pointer writer = WriterType::New();
reader->SetFileName( argv[1] );
writer->SetFileName( argv[2] );
const double angleInDegrees = atof( argv[3] );
// Software Guide : BeginLatex
//
// The Resampling filter is instantiated and created just like in previous examples.
// The Transform is instantiated and connected to the resampling filter.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::ResampleImageFilter<
InputImageType, OutputImageType > FilterType;
FilterType::Pointer filter = FilterType::New();
typedef itk::AffineTransform< double, Dimension > TransformType;
TransformType::Pointer transform = TransformType::New();
filter->SetTransform( transform );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The salient feature of this example is the use of the
// \doxygen{BSplineInterpolateImageFunction}, which uses cubic BSplines in
// order to interpolate the resampled image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::BSplineInterpolateImageFunction<
InputImageType, double > InterpolatorType;
InterpolatorType::Pointer interpolator = InterpolatorType::New();
filter->SetInterpolator( interpolator );
filter->SetDefaultPixelValue( 100 );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The parameters of the output image are taken from the input image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
reader->Update();
const InputImageType::SpacingType&
spacing = reader->GetOutput()->GetSpacing();
const InputImageType::PointType&
origin = reader->GetOutput()->GetOrigin();
const InputImageType::DirectionType&
direction = reader->GetOutput()->GetDirection();
InputImageType::SizeType size =
reader->GetOutput()->GetLargestPossibleRegion().GetSize();
filter->SetOutputOrigin( origin );
filter->SetOutputSpacing( spacing );
filter->SetOutputDirection( direction );
filter->SetSize( size );
// Software Guide : EndCodeSnippet
filter->SetInput( reader->GetOutput() );
writer->SetInput( filter->GetOutput() );
TransformType::OutputVectorType translation1;
const double imageCenterX = origin[0] + spacing[0] * size[0] / 2.0;
const double imageCenterY = origin[1] + spacing[1] * size[1] / 2.0;
translation1[0] = -imageCenterX;
translation1[1] = -imageCenterY;
transform->Translate( translation1 );
std::cout << "imageCenterX = " << imageCenterX << std::endl;
std::cout << "imageCenterY = " << imageCenterY << std::endl;
const double degreesToRadians = std::atan(1.0) / 45.0;
const double angle = angleInDegrees * degreesToRadians;
transform->Rotate2D( -angle, false );
TransformType::OutputVectorType translation2;
translation2[0] = imageCenterX;
translation2[1] = imageCenterY;
transform->Translate( translation2, false );
// Software Guide : BeginLatex
//
// The output of the resampling filter is connected to a writer and the
// execution of the pipeline is triggered by a writer update.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
try
{
writer->Update();
}
catch( itk::ExceptionObject & excep )
{
std::cerr << "Exception catched !" << std::endl;
std::cerr << excep << std::endl;
}
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}
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