ITK  5.2.0
Insight Toolkit
Examples/Filtering/SpatialObjectToImage1.cxx
/*=========================================================================
*
* Copyright NumFOCUS
*
* 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
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* See the License for the specific language governing permissions and
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*=========================================================================*/
// Software Guide : BeginLatex
//
// This example illustrates the use of the
// \doxygen{SpatialObjectToImageFilter}. This filter expect a
// \doxygen{SpatialObject} as input, and rasterize it in order to generate an
// output image. This is particularly useful for generating synthetic images,
// in particular binary images containing a mask.
//
// \index{itk::SpatialObjectToImageFilter|textbf}
//
// Software Guide : EndLatex
// Software Guide : BeginLatex
//
// The first step required for using this filter is to include its header
// file
//
// \index{itk::SpatialObjectToImageFilter!header}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// This filter takes as input a SpatialObject. However, SpatialObject can be
// grouped together in a hierarchical structure in order to produce more
// complex shapes. In this case, we illustrate how to aggregate multiple
// basic shapes. We should, therefore, include the headers of the individual
// elementary SpatialObjects.
//
// \index{itk::EllipseSpatialObject!header}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Then we include the header of the \doxygen{GroupSpatialObject} that will
// group together these instances of SpatialObjects.
//
// \index{itk::GroupSpatialObject!header}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
int
main(int argc, char * argv[])
{
if (argc != 2)
{
std::cerr << "Usage: " << argv[0] << " outputimagefile " << std::endl;
return EXIT_FAILURE;
}
// Software Guide : BeginLatex
//
// We declare the pixel type and dimension of the image to be produced as
// output.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using PixelType = signed short;
constexpr unsigned int Dimension = 3;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Using the same dimension, we instantiate the types of the elementary
// SpatialObjects that we plan to group, and we instantiate as well the
// type of the SpatialObject that will hold the group together.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We instantiate the SpatialObjectToImageFilter type by using as template
// arguments the input SpatialObject and the output image types.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using SpatialObjectToImageFilterType =
SpatialObjectToImageFilterType::Pointer imageFilter =
SpatialObjectToImageFilterType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The SpatialObjectToImageFilter requires that the user defines the grid
// parameters of the output image. This includes the number of pixels along
// each dimension, the pixel spacing, image direction and
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
size[0] = 50;
size[1] = 50;
size[2] = 150;
imageFilter->SetSize(size);
// Software Guide : EndCodeSnippet
// Software Guide : BeginCodeSnippet
ImageType::SpacingType spacing;
spacing[0] = 100.0 / size[0];
spacing[1] = 100.0 / size[1];
spacing[2] = 300.0 / size[2];
imageFilter->SetSpacing(spacing);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We create the elementary shapes that are going to be composed into the
// group spatial objects.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
EllipseType::Pointer ellipse = EllipseType::New();
TubeType::Pointer tube1 = TubeType::New();
TubeType::Pointer tube2 = TubeType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The Elementary shapes have internal parameters of their own. These
// parameters define the geometrical characteristics of the basic shapes.
// For example, a tube is defined by its radius and height.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
ellipse->SetRadiusInObjectSpace(size[0] * 0.2 * spacing[0]);
typename TubeType::PointType point;
typename TubeType::TubePointType tubePoint;
typename TubeType::TubePointListType tubePointList;
point[0] = size[0] * 0.2 * spacing[0];
point[1] = size[1] * 0.2 * spacing[1];
point[2] = size[2] * 0.2 * spacing[2];
tubePoint.SetPositionInObjectSpace(point);
tubePoint.SetRadiusInObjectSpace(size[0] * 0.05 * spacing[0]);
tubePointList.push_back(tubePoint);
point[0] = size[0] * 0.8 * spacing[0];
point[1] = size[1] * 0.2 * spacing[1];
point[2] = size[2] * 0.2 * spacing[2];
tubePoint.SetPositionInObjectSpace(point);
tubePoint.SetRadiusInObjectSpace(size[0] * 0.05 * spacing[0]);
tubePointList.push_back(tubePoint);
tube1->SetPoints(tubePointList);
tubePointList.clear();
point[0] = size[0] * 0.2 * spacing[0];
point[1] = size[1] * 0.8 * spacing[1];
point[2] = size[2] * 0.2 * spacing[2];
tubePoint.SetPositionInObjectSpace(point);
tubePoint.SetRadiusInObjectSpace(size[0] * 0.05 * spacing[0]);
tubePointList.push_back(tubePoint);
point[0] = size[0] * 0.8 * spacing[0];
point[1] = size[1] * 0.8 * spacing[1];
point[2] = size[2] * 0.8 * spacing[1];
tubePoint.SetPositionInObjectSpace(point);
tubePoint.SetRadiusInObjectSpace(size[0] * 0.05 * spacing[0]);
tubePointList.push_back(tubePoint);
tube2->SetPoints(tubePointList);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Each one of these components will be placed in a different position and
// orientation. We define transforms in order to specify those relative
// positions and orientations.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using TransformType = GroupType::TransformType;
TransformType::Pointer transform1 = TransformType::New();
TransformType::Pointer transform2 = TransformType::New();
TransformType::Pointer transform3 = TransformType::New();
transform1->SetIdentity();
transform2->SetIdentity();
transform3->SetIdentity();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Then we set the specific values of the transform parameters, and we
// assign the transforms to the elementary shapes.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
TransformType::OutputVectorType translation;
translation[0] = size[0] * spacing[0] / 2.0;
translation[1] = size[1] * spacing[1] / 4.0;
translation[2] = size[2] * spacing[2] / 2.0;
transform1->Translate(translation, false);
translation[1] = size[1] * spacing[1] / 2.0;
translation[2] = size[2] * spacing[2] * 0.22;
transform2->Rotate(1, 2, itk::Math::pi / 2.0);
transform2->Translate(translation, false);
translation[2] = size[2] * spacing[2] * 0.78;
transform3->Rotate(1, 2, itk::Math::pi / 2.0);
transform3->Translate(translation, false);
ellipse->SetObjectToParentTransform(transform1);
tube1->SetObjectToParentTransform(transform2);
tube2->SetObjectToParentTransform(transform3);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The elementary shapes are aggregated in a parent group, that in turn is
// passed as input to the filter.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
GroupType::Pointer group = GroupType::New();
group->AddChild(ellipse);
group->AddChild(tube1);
group->AddChild(tube2);
ellipse->Update();
tube1->Update();
tube2->Update();
imageFilter->SetInput(group);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// By default, the filter will rasterize the aggregation of elementary
// shapes and will assign a pixel value to locations that fall inside of
// any of the elementary shapes, and a different pixel value to locations
// that fall outside of all of the elementary shapes. It is possible,
// however, to generate richer images if we allow the filter to use the
// values that the elementary spatial objects return via their
// \code{ValueAt} methods. This is what we choose to do in this example, by
// using the following code.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
const PixelType airHounsfieldUnits = -1000;
constexpr PixelType boneHounsfieldUnits = 800;
ellipse->SetDefaultInsideValue(boneHounsfieldUnits);
tube1->SetDefaultInsideValue(boneHounsfieldUnits);
tube2->SetDefaultInsideValue(boneHounsfieldUnits);
ellipse->SetDefaultOutsideValue(airHounsfieldUnits);
tube1->SetDefaultOutsideValue(airHounsfieldUnits);
tube2->SetDefaultOutsideValue(airHounsfieldUnits);
imageFilter->SetUseObjectValue(true);
imageFilter->SetOutsideValue(airHounsfieldUnits);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Finally we are ready to run the filter. We use the typical invocation of
// the \code{Update} method, and we instantiate an \code{ImageFileWriter}
// in order to save the generated image into a file.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using WriterType = itk::ImageFileWriter<ImageType>;
WriterType::Pointer writer = WriterType::New();
writer->SetFileName(argv[1]);
writer->SetInput(imageFilter->GetOutput());
try
{
imageFilter->Update();
writer->Update();
}
catch (const itk::ExceptionObject & excp)
{
std::cerr << excp << std::endl;
return EXIT_FAILURE;
}
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}
itk::TubeSpatialObject
Representation of a tube based on the spatial object classes.
Definition: itkTubeSpatialObject.h:42
itkEllipseSpatialObject.h
itk::GTest::TypedefsAndConstructors::Dimension2::PointType
ImageBaseType::PointType PointType
Definition: itkGTestTypedefsAndConstructors.h:51
itk::GTest::TypedefsAndConstructors::Dimension2::SizeType
ImageBaseType::SizeType SizeType
Definition: itkGTestTypedefsAndConstructors.h:49
itk::SpatialObjectToImageFilter
Base class for filters that take a SpatialObject as input and produce an image as output....
Definition: itkSpatialObjectToImageFilter.h:41
itk::EllipseSpatialObject
Definition: itkEllipseSpatialObject.h:38
itkGroupSpatialObject.h
itk::ImageFileWriter
Writes image data to a single file.
Definition: itkImageFileWriter.h:87
itkSpatialObjectToImageFilter.h
itkImageFileWriter.h
itk::Size::SetSize
void SetSize(const SizeValueType val[VDimension])
Definition: itkSize.h:179
itk::Image
Templated n-dimensional image class.
Definition: itkImage.h:86
itk::Math::pi
static constexpr double pi
Definition: itkMath.h:64
itk::GroupSpatialObject
Representation of a group based on the spatial object classes.
Definition: itkGroupSpatialObject.h:39
itk::GTest::TypedefsAndConstructors::Dimension2::Dimension
constexpr unsigned int Dimension
Definition: itkGTestTypedefsAndConstructors.h:44
itkTubeSpatialObject.h