STYLE: Use auto for declaration of variables initialized by New()

Replaced initializations of the forms `T::Pointer var = T::New()` and
`typename T::Pointer var = T::New()` with `auto var = T::New()`, to reduce
code redundancy.

Using Notepad++ v8.3.3, Find in Files (Regular expression):

  Find what:  typename (\w+)::Pointer[ ]+(\w+) = \1::New\(\);
  Replace with:  auto $2 = $1::New\(\);

And then again without `typename`.

Following ITK pull request InsightSoftwareConsortium/ITK#2994
commit InsightSoftwareConsortium/ITK@2f291f8
"STYLE: Use `auto` for variables initialized by `New()` in Examples",
by Jon Haitz Legarreta Gorroño, merged on 27 December 2021.

Author: N-Dekker

src/Bridge/VtkGlue/ConvertAnRGBitkImageTovtkImageData/Code.cxx

@@ -43,7 +43,7 @@ main(int argc, char * argv[])
   const auto input = itk::ReadImage<ImageType>(inputFileName);
 
   using FilterType = itk::ImageToVTKImageFilter<ImageType>;
-  FilterType::Pointer filter = FilterType::New();
+  auto filter = FilterType::New();
   filter->SetInput(input);
 
   try

src/Bridge/VtkGlue/ConvertAnitkImageTovtkImageData/Code.cxx

@@ -41,7 +41,7 @@ main(int argc, char * argv[])
   const auto input = itk::ReadImage<ImageType>(inputFileName);
 
   using FilterType = itk::ImageToVTKImageFilter<ImageType>;
-  FilterType::Pointer filter = FilterType::New();
+  auto filter = FilterType::New();
   filter->SetInput(input);
 
   try

src/Bridge/VtkGlue/ConvertRGBvtkImageDataToAnitkImage/Code.cxx

@@ -46,7 +46,7 @@ main(int argc, char * argv[])
   reader->SetDataScalarTypeToUnsignedChar();
 
   using FilterType = itk::VTKImageToImageFilter<ImageType>;
-  FilterType::Pointer filter = FilterType::New();
+  auto filter = FilterType::New();
   filter->SetInput(reader->GetOutput());
 
   try

src/Bridge/VtkGlue/ConvertvtkImageDataToAnitkImage/Code.cxx

@@ -49,7 +49,7 @@ main(int argc, char * argv[])
   magnitude->Update();
 
   using FilterType = itk::VTKImageToImageFilter<ImageType>;
-  FilterType::Pointer filter = FilterType::New();
+  auto filter = FilterType::New();
   filter->SetInput(magnitude->GetOutput());
 
   try

src/Bridge/VtkGlue/VTKImageToITKImage/Code.cxx

@@ -51,12 +51,12 @@ main(int argc, char * argv[])
 
   using VTKImageToImageType = itk::VTKImageToImageFilter<ImageType>;
 
-  VTKImageToImageType::Pointer vtkImageToImageFilter = VTKImageToImageType::New();
+  auto vtkImageToImageFilter = VTKImageToImageType::New();
   vtkImageToImageFilter->SetInput(luminanceFilter->GetOutput());
   // vtkImageToImageFilter->SetInput(reader->GetOutput());
   vtkImageToImageFilter->Update();
 
-  ImageType::Pointer image = ImageType::New();
+  auto image = ImageType::New();
   image->Graft(vtkImageToImageFilter->GetOutput()); // Need to do this because QuickView can't accept const
 
 #ifdef ENABLE_QUICKVIEW

src/Bridge/VtkGlue/VisualizeEvolvingDense2DLevelSetAsElevationMap/Code.cxx

@@ -62,7 +62,7 @@ main(int argc, char * argv[])
   // Generate a binary mask that will be used as initialization for the level
   // set evolution.
   using BinaryImageType = itk::Image<LevelSetOutputType, Dimension>;
-  BinaryImageType::Pointer binary = BinaryImageType::New();
+  auto binary = BinaryImageType::New();
   binary->SetRegions(input->GetLargestPossibleRegion());
   binary->CopyInformation(input);
   binary->Allocate();
@@ -90,19 +90,19 @@ main(int argc, char * argv[])
   // convert a binary mask to a level-set function
   using BinaryImageToLevelSetType = itk::BinaryImageToLevelSetImageAdaptor<BinaryImageType, LevelSetType>;
 
-  BinaryImageToLevelSetType::Pointer adaptor = BinaryImageToLevelSetType::New();
+  auto adaptor = BinaryImageToLevelSetType::New();
   adaptor->SetInputImage(binary);
   adaptor->Initialize();
   LevelSetType::Pointer levelSet = adaptor->GetLevelSet();
 
   // The Heaviside function
   using HeavisideFunctionType = itk::SinRegularizedHeavisideStepFunction<LevelSetRealType, LevelSetRealType>;
-  HeavisideFunctionType::Pointer heaviside = HeavisideFunctionType::New();
+  auto heaviside = HeavisideFunctionType::New();
   heaviside->SetEpsilon(1.5);
 
   // Create the level set container
   using LevelSetContainerType = itk::LevelSetContainer<itk::IdentifierType, LevelSetType>;
-  LevelSetContainerType::Pointer levelSetContainer = LevelSetContainerType::New();
+  auto levelSetContainer = LevelSetContainerType::New();
   levelSetContainer->SetHeaviside(heaviside);
   levelSetContainer->AddLevelSet(0, levelSet);
 
@@ -111,51 +111,51 @@ main(int argc, char * argv[])
   // // Chan and Vese internal term
   using ChanAndVeseInternalTermType =
     itk::LevelSetEquationChanAndVeseInternalTerm<InputImageType, LevelSetContainerType>;
-  ChanAndVeseInternalTermType::Pointer cvInternalTerm = ChanAndVeseInternalTermType::New();
+  auto cvInternalTerm = ChanAndVeseInternalTermType::New();
   cvInternalTerm->SetInput(input);
   cvInternalTerm->SetCoefficient(0.5);
 
   // // Chan and Vese external term
   using ChanAndVeseExternalTermType =
     itk::LevelSetEquationChanAndVeseExternalTerm<InputImageType, LevelSetContainerType>;
-  ChanAndVeseExternalTermType::Pointer cvExternalTerm = ChanAndVeseExternalTermType::New();
+  auto cvExternalTerm = ChanAndVeseExternalTermType::New();
   cvExternalTerm->SetInput(input);
 
   // Create term container (equation rhs)
   using TermContainerType = itk::LevelSetEquationTermContainer<InputImageType, LevelSetContainerType>;
-  TermContainerType::Pointer termContainer = TermContainerType::New();
+  auto termContainer = TermContainerType::New();
   termContainer->SetLevelSetContainer(levelSetContainer);
   termContainer->SetInput(input);
   termContainer->AddTerm(0, cvInternalTerm);
   termContainer->AddTerm(1, cvExternalTerm);
 
   // Create equation container
   using EquationContainerType = itk::LevelSetEquationContainer<TermContainerType>;
-  EquationContainerType::Pointer equationContainer = EquationContainerType::New();
+  auto equationContainer = EquationContainerType::New();
   equationContainer->SetLevelSetContainer(levelSetContainer);
   equationContainer->AddEquation(0, termContainer);
 
   // Create stopping criteria
   using StoppingCriterionType = itk::LevelSetEvolutionNumberOfIterationsStoppingCriterion<LevelSetContainerType>;
-  StoppingCriterionType::Pointer criterion = StoppingCriterionType::New();
+  auto criterion = StoppingCriterionType::New();
   criterion->SetNumberOfIterations(numberOfIterations);
 
   // Create the visualizer
   using VisualizationType = itk::VTKVisualize2DLevelSetAsElevationMap<InputImageType, LevelSetType>;
-  VisualizationType::Pointer visualizer = VisualizationType::New();
+  auto visualizer = VisualizationType::New();
   visualizer->SetInputImage(input);
   visualizer->SetLevelSet(levelSet);
   visualizer->SetScreenCapture(true);
 
   // Create evolution class
   using LevelSetEvolutionType = itk::LevelSetEvolution<EquationContainerType, LevelSetType>;
-  LevelSetEvolutionType::Pointer evolution = LevelSetEvolutionType::New();
+  auto evolution = LevelSetEvolutionType::New();
   evolution->SetEquationContainer(equationContainer);
   evolution->SetStoppingCriterion(criterion);
   evolution->SetLevelSetContainer(levelSetContainer);
 
   using IterationUpdateCommandType = itk::LevelSetIterationUpdateCommand<LevelSetEvolutionType, VisualizationType>;
-  IterationUpdateCommandType::Pointer iterationUpdateCommand = IterationUpdateCommandType::New();
+  auto iterationUpdateCommand = IterationUpdateCommandType::New();
   iterationUpdateCommand->SetFilterToUpdate(visualizer);
   iterationUpdateCommand->SetUpdatePeriod(5);
 

src/Bridge/VtkGlue/VisualizeEvolvingDense2DLevelSetZeroSet/Code.cxx

@@ -62,7 +62,7 @@ main(int argc, char * argv[])
   // Generate a binary mask that will be used as initialization for the level
   // set evolution.
   using BinaryImageType = itk::Image<LevelSetOutputType, Dimension>;
-  BinaryImageType::Pointer binary = BinaryImageType::New();
+  auto binary = BinaryImageType::New();
   binary->SetRegions(input->GetLargestPossibleRegion());
   binary->CopyInformation(input);
   binary->Allocate();
@@ -90,19 +90,19 @@ main(int argc, char * argv[])
   // convert a binary mask to a level-set function
   using BinaryImageToLevelSetType = itk::BinaryImageToLevelSetImageAdaptor<BinaryImageType, LevelSetType>;
 
-  BinaryImageToLevelSetType::Pointer adaptor = BinaryImageToLevelSetType::New();
+  auto adaptor = BinaryImageToLevelSetType::New();
   adaptor->SetInputImage(binary);
   adaptor->Initialize();
   LevelSetType::Pointer levelSet = adaptor->GetModifiableLevelSet();
 
   // The Heaviside function
   using HeavisideFunctionType = itk::SinRegularizedHeavisideStepFunction<LevelSetRealType, LevelSetRealType>;
-  HeavisideFunctionType::Pointer heaviside = HeavisideFunctionType::New();
+  auto heaviside = HeavisideFunctionType::New();
   heaviside->SetEpsilon(1.5);
 
   // Create the level set container
   using LevelSetContainerType = itk::LevelSetContainer<itk::IdentifierType, LevelSetType>;
-  LevelSetContainerType::Pointer levelSetContainer = LevelSetContainerType::New();
+  auto levelSetContainer = LevelSetContainerType::New();
   levelSetContainer->SetHeaviside(heaviside);
   levelSetContainer->AddLevelSet(0, levelSet);
 
@@ -111,51 +111,51 @@ main(int argc, char * argv[])
   // // Chan and Vese internal term
   using ChanAndVeseInternalTermType =
     itk::LevelSetEquationChanAndVeseInternalTerm<InputImageType, LevelSetContainerType>;
-  ChanAndVeseInternalTermType::Pointer cvInternalTerm = ChanAndVeseInternalTermType::New();
+  auto cvInternalTerm = ChanAndVeseInternalTermType::New();
   cvInternalTerm->SetInput(input);
   cvInternalTerm->SetCoefficient(0.5);
 
   // // Chan and Vese external term
   using ChanAndVeseExternalTermType =
     itk::LevelSetEquationChanAndVeseExternalTerm<InputImageType, LevelSetContainerType>;
-  ChanAndVeseExternalTermType::Pointer cvExternalTerm = ChanAndVeseExternalTermType::New();
+  auto cvExternalTerm = ChanAndVeseExternalTermType::New();
   cvExternalTerm->SetInput(input);
 
   // Create term container (equation rhs)
   using TermContainerType = itk::LevelSetEquationTermContainer<InputImageType, LevelSetContainerType>;
-  TermContainerType::Pointer termContainer = TermContainerType::New();
+  auto termContainer = TermContainerType::New();
   termContainer->SetLevelSetContainer(levelSetContainer);
   termContainer->SetInput(input);
   termContainer->AddTerm(0, cvInternalTerm);
   termContainer->AddTerm(1, cvExternalTerm);
 
   // Create equation container
   using EquationContainerType = itk::LevelSetEquationContainer<TermContainerType>;
-  EquationContainerType::Pointer equationContainer = EquationContainerType::New();
+  auto equationContainer = EquationContainerType::New();
   equationContainer->SetLevelSetContainer(levelSetContainer);
   equationContainer->AddEquation(0, termContainer);
 
   // Create stopping criteria
   using StoppingCriterionType = itk::LevelSetEvolutionNumberOfIterationsStoppingCriterion<LevelSetContainerType>;
-  StoppingCriterionType::Pointer criterion = StoppingCriterionType::New();
+  auto criterion = StoppingCriterionType::New();
   criterion->SetNumberOfIterations(numberOfIterations);
 
   // Create the visualizer
   using VisualizationType = itk::VTKVisualizeImageLevelSetIsoValues<InputImageType, LevelSetType>;
-  VisualizationType::Pointer visualizer = VisualizationType::New();
+  auto visualizer = VisualizationType::New();
   visualizer->SetInputImage(input);
   visualizer->SetLevelSet(levelSet);
   visualizer->SetScreenCapture(true);
 
   // Create evolution class
   using LevelSetEvolutionType = itk::LevelSetEvolution<EquationContainerType, LevelSetType>;
-  LevelSetEvolutionType::Pointer evolution = LevelSetEvolutionType::New();
+  auto evolution = LevelSetEvolutionType::New();
   evolution->SetEquationContainer(equationContainer);
   evolution->SetStoppingCriterion(criterion);
   evolution->SetLevelSetContainer(levelSetContainer);
 
   using IterationUpdateCommandType = itk::LevelSetIterationUpdateCommand<LevelSetEvolutionType, VisualizationType>;
-  IterationUpdateCommandType::Pointer iterationUpdateCommand = IterationUpdateCommandType::New();
+  auto iterationUpdateCommand = IterationUpdateCommandType::New();
   iterationUpdateCommand->SetFilterToUpdate(visualizer);
   iterationUpdateCommand->SetUpdatePeriod(5);
 

src/Bridge/VtkGlue/VisualizeStaticDense2DLevelSetAsElevationMap/Code.cxx

@@ -60,29 +60,29 @@ main(int argc, char * argv[])
   // Generate a binary mask that will be used as initialization for the level
   // set evolution.
   using OtsuFilterType = itk::OtsuMultipleThresholdsImageFilter<InputImageType, LevelSetImageType>;
-  OtsuFilterType::Pointer otsu = OtsuFilterType::New();
+  auto otsu = OtsuFilterType::New();
   otsu->SetInput(input);
   otsu->SetNumberOfHistogramBins(256);
   otsu->SetNumberOfThresholds(1);
 
   using RescaleType = itk::RescaleIntensityImageFilter<LevelSetImageType, LevelSetImageType>;
-  RescaleType::Pointer rescaler = RescaleType::New();
+  auto rescaler = RescaleType::New();
   rescaler->SetInput(otsu->GetOutput());
   rescaler->SetOutputMinimum(0);
   rescaler->SetOutputMaximum(1);
 
   // convert a binary mask to a level-set function
   using BinaryImageToLevelSetType = itk::BinaryImageToLevelSetImageAdaptor<LevelSetImageType, LevelSetType>;
 
-  BinaryImageToLevelSetType::Pointer adaptor = BinaryImageToLevelSetType::New();
+  auto adaptor = BinaryImageToLevelSetType::New();
   adaptor->SetInputImage(rescaler->GetOutput());
   adaptor->Initialize();
 
   LevelSetType::Pointer levelSet = adaptor->GetModifiableLevelSet();
 
   // Create the visualizer
   using VisualizationType = itk::VTKVisualize2DLevelSetAsElevationMap<InputImageType, LevelSetType>;
-  VisualizationType::Pointer visualizer = VisualizationType::New();
+  auto visualizer = VisualizationType::New();
   visualizer->SetInputImage(input);
   visualizer->SetLevelSet(levelSet);
 

src/Bridge/VtkGlue/VisualizeStaticDense2DLevelSetZeroSet/Code.cxx

@@ -60,29 +60,29 @@ main(int argc, char * argv[])
   // Generate a binary mask that will be used as initialization for the level
   // set evolution.
   using OtsuFilterType = itk::OtsuMultipleThresholdsImageFilter<InputImageType, LevelSetImageType>;
-  OtsuFilterType::Pointer otsu = OtsuFilterType::New();
+  auto otsu = OtsuFilterType::New();
   otsu->SetInput(input);
   otsu->SetNumberOfHistogramBins(256);
   otsu->SetNumberOfThresholds(1);
 
   using RescaleType = itk::RescaleIntensityImageFilter<LevelSetImageType, LevelSetImageType>;
-  RescaleType::Pointer rescaler = RescaleType::New();
+  auto rescaler = RescaleType::New();
   rescaler->SetInput(otsu->GetOutput());
   rescaler->SetOutputMinimum(0);
   rescaler->SetOutputMaximum(1);
 
   // convert a binary mask to a level-set function
   using BinaryImageToLevelSetType = itk::BinaryImageToLevelSetImageAdaptor<LevelSetImageType, LevelSetType>;
 
-  BinaryImageToLevelSetType::Pointer adaptor = BinaryImageToLevelSetType::New();
+  auto adaptor = BinaryImageToLevelSetType::New();
   adaptor->SetInputImage(rescaler->GetOutput());
   adaptor->Initialize();
 
   LevelSetType::Pointer levelSet = adaptor->GetModifiableLevelSet();
 
   // Create the visualizer
   using VisualizationType = itk::VTKVisualizeImageLevelSetIsoValues<InputImageType, LevelSetType>;
-  VisualizationType::Pointer visualizer = VisualizationType::New();
+  auto visualizer = VisualizationType::New();
   visualizer->SetInputImage(input);
   visualizer->SetLevelSet(levelSet);
 

src/Bridge/VtkGlue/VisualizeStaticMalcolm2DLevelSetLayers/Code.cxx

@@ -50,29 +50,29 @@ main(int argc, char * argv[])
   // Generate a binary mask that will be used as initialization for the level
   // set evolution.
   using OtsuFilterType = itk::OtsuMultipleThresholdsImageFilter<InputImageType, InputImageType>;
-  OtsuFilterType::Pointer otsu = OtsuFilterType::New();
+  auto otsu = OtsuFilterType::New();
   otsu->SetInput(input);
   otsu->SetNumberOfHistogramBins(256);
   otsu->SetNumberOfThresholds(1);
 
   using RescaleType = itk::RescaleIntensityImageFilter<InputImageType, InputImageType>;
-  RescaleType::Pointer rescaler = RescaleType::New();
+  auto rescaler = RescaleType::New();
   rescaler->SetInput(otsu->GetOutput());
   rescaler->SetOutputMinimum(0);
   rescaler->SetOutputMaximum(1);
 
   // convert a binary mask to a level-set function
   using BinaryImageToLevelSetType = itk::BinaryImageToLevelSetImageAdaptor<InputImageType, LevelSetType>;
 
-  BinaryImageToLevelSetType::Pointer adaptor = BinaryImageToLevelSetType::New();
+  auto adaptor = BinaryImageToLevelSetType::New();
   adaptor->SetInputImage(rescaler->GetOutput());
   adaptor->Initialize();
 
   LevelSetType::Pointer levelSet = adaptor->GetModifiableLevelSet();
 
   // Create the visualizer
   using VisualizationType = itk::VTKVisualize2DSparseLevelSetLayers<InputImageType, LevelSetType>;
-  VisualizationType::Pointer visualizer = VisualizationType::New();
+  auto visualizer = VisualizationType::New();
   visualizer->SetInputImage(input);
   visualizer->SetLevelSet(levelSet);
   visualizer->SetScreenCapture(true);