ITK  5.3.0
Insight Toolkit
Examples/IO/TransformReadWrite.cxx
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* Licensed under the Apache License, Version 2.0 (the "License");
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// Software Guide : BeginLatex
//
// \index{itk::TransformReader}
// \index{itk::TransformWriter}
//
// This example shows how to read and write a transform
// using the \doxygen{TransformFileReader} and
// \doxygen{TransformFileWriter}.
// Let's first include the two appropriate header files.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
int
main(int argc, char * argv[])
{
if (argc < 2)
{
std::cerr << "Usage: " << argv[0] << " transformFile" << std::endl;
return EXIT_FAILURE;
}
const char * transformFileName = argv[1];
using ScalarType = double;
constexpr unsigned int Dimension = 3;
using CompositeTransformType =
CompositeTransformType::Pointer composite = CompositeTransformType::New();
using AffineTransformType = itk::AffineTransform<ScalarType, Dimension>;
AffineTransformType::Pointer affine = AffineTransformType::New();
AffineTransformType::InputPointType cor;
cor.Fill(12);
affine->SetCenter(cor);
composite->AddTransform(affine);
constexpr unsigned int SplineOrder = 5;
using BSplineTransformType =
using BSplineTransformFType =
// By default only BSpline transforms of order 3 are registered.
// Manually register this order 5 bspline for both float and double
// scalar types, so that we can read the correct order transform.
BSplineTransformType::Pointer bspline = BSplineTransformType::New();
BSplineTransformType::OriginType origin;
origin.Fill(100);
BSplineTransformType::PhysicalDimensionsType dimensions;
dimensions.Fill(1.5 * 9.0);
bspline->SetTransformDomainOrigin(origin);
bspline->SetTransformDomainPhysicalDimensions(dimensions);
BSplineTransformType::ParametersType parameters(
bspline->GetNumberOfParameters());
bspline->SetParameters(parameters);
bspline->SetIdentity();
composite->AddTransform(bspline);
// Software Guide : BeginLatex
//
// The transform reader and writer is templated. The conversion is precision
// done if necessary when writing or reading the file. We create a writer
// using smart pointers.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using TransformWriterType = itk::TransformFileWriterTemplate<ScalarType>;
TransformWriterType::Pointer writer = TransformWriterType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We add a CompositeTransform with the
// SetInput() function. This function takes any \doxygen{Transform}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
writer->SetInput(composite);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Then we set the filename using the SetFileName() function.
// Then we call the Update()function to write the transform(s)
// onto the disk.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
writer->SetFileName(transformFileName);
// Software Guide : EndCodeSnippet
try
{
// Software Guide : BeginCodeSnippet
writer->Update();
// Software Guide : EndCodeSnippet
}
catch (const itk::ExceptionObject & excp)
{
std::cerr << "Error while saving the transforms" << std::endl;
std::cerr << excp << std::endl;
return EXIT_FAILURE;
}
// Software Guide : BeginLatex
//
// In order to read a transform file, we instantiate a TransformFileReader.
// Like the writer, the reader is templated.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using ReadScalarType = float;
using TransformReaderType =
TransformReaderType::Pointer reader = TransformReaderType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We then set the name of the file we want to read, and call the
// Update() function.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
reader->SetFileName(transformFileName);
// Software Guide : EndCodeSnippet
try
{
// Software Guide : BeginCodeSnippet
reader->Update();
// Software Guide : EndCodeSnippet
}
catch (const itk::ExceptionObject & excp)
{
std::cerr << "Error while reading the transform file" << std::endl;
std::cerr << excp << std::endl;
std::cerr << "[FAILED]" << std::endl;
return EXIT_FAILURE;
}
// Software Guide : BeginLatex
//
// The transform reader is templated and it returns a list
// of \doxygen{Transform}'s. Even thought the reader instantiate the
// appropriate transform class when reading the file, it is up to the user
// to do the approriate cast. To get the output list of transform we use the
// GetTransformList() function.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
const TransformReaderType::TransformListType * transforms =
reader->GetTransformList();
std::cout << "Number of transforms = " << transforms->size() << std::endl;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We then use an STL iterator to go through the list of transforms. We show
// here how to do the proper casting of the resulting transform.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using ReadCompositeTransformType =
auto it = transforms->begin();
if (!strcmp((*it)->GetNameOfClass(), "CompositeTransform"))
{
ReadCompositeTransformType::Pointer compositeRead =
static_cast<ReadCompositeTransformType *>((*it).GetPointer());
compositeRead->Print(std::cout);
}
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}
itk::CompositeTransform
This class contains a list of transforms and concatenates them by composition.
Definition: itkCompositeTransform.h:87
itkTransformFileReader.h
itkAffineTransform.h
itk::AffineTransform
Definition: itkAffineTransform.h:101
itk::LightObject::Print
void Print(std::ostream &os, Indent indent=0) const
itk::BSplineTransform
Deformable transform using a BSpline representation.
Definition: itkBSplineTransform.h:103
itkBSplineTransform.h
itk::TransformFileReaderTemplate
TODO.
Definition: itkTransformFileReader.h:37
itkTransformFactory.h
itk::TransformFactory::RegisterTransform
static void RegisterTransform()
Definition: itkTransformFactory.h:49
itk::TransformFileWriterTemplate
TODO.
Definition: itkTransformFileWriter.h:39
itkCompositeTransform.h
itkTransformFileWriter.h
itk::GTest::TypedefsAndConstructors::Dimension2::Dimension
constexpr unsigned int Dimension
Definition: itkGTestTypedefsAndConstructors.h:44