ITK  5.4.0 Insight Toolkit
Examples/Filtering/FlipImageFilter.cxx
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// Software Guide : BeginCommandLineArgs
// INPUTS: {BrainProtonDensitySlice.png}
// OUTPUTS: {FlipImageFilterOutput.png}
// ARGUMENTS: 0 1
// Software Guide : EndCommandLineArgs
// Software Guide : BeginLatex
//
// The \doxygen{FlipImageFilter} is used for flipping the image content in
// any of the coordinate axes. This filter must be used with \textbf{EXTREME}
// caution. You probably don't want to appear in the newspapers as
// responsible for a surgery mistake in which a doctor extirpates the left
// kidney when he should have extracted the right one\footnote{\emph{Wrong
// side} surgery accounts for $2\%$ of the reported medical errors in the
// United States. Trivial... but equally dangerous.} . If that prospect
// doesn't scare you, maybe it is time for you to reconsider your career in
// medical image processing. Flipping effects which seem innocuous at first
// view may still have dangerous consequences. For example, flipping the
// cranio-caudal axis of a CT scan forces an observer to flip the left-right
// axis in order to make sense of the image.
//
// \index{itk::FlipImageFilter}
//
// Software Guide : EndLatex
#include "itkImage.h"
// Software Guide : BeginLatex
//
// The header file corresponding to this filter should be included first.
//
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
int
main(int argc, char * argv[])
{
if (argc < 5)
{
std::cerr << "Usage: " << std::endl;
std::cerr << argv[0]
<< " inputImageFile outputImageFile flipAxisX flipAxisY"
<< std::endl;
return EXIT_FAILURE;
}
// Software Guide : BeginLatex
//
// Then the pixel types for input and output image must be defined and,
// with them, the image types can be instantiated.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using PixelType = unsigned char;
using ImageType = itk::Image<PixelType, 2>;
// Software Guide : EndCodeSnippet
using WriterType = itk::ImageFileWriter<ImageType>;
auto writer = WriterType::New();
writer->SetFileName(argv[2]);
// Software Guide : BeginLatex
//
// Using the image types it is now possible to instantiate the filter type
// and create the filter object.
//
// \index{itk::FlipImageFilter!instantiation}
// \index{itk::FlipImageFilter!New()}
// \index{itk::FlipImageFilter!Pointer}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using FilterType = itk::FlipImageFilter<ImageType>;
auto filter = FilterType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The axes to flip are specified in the form of an Array. In this case we
// take them from the command line arguments.
//
// \index{itk::FlipImageFilter!Neighborhood}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using FlipAxesArrayType = FilterType::FlipAxesArrayType;
FlipAxesArrayType flipArray;
flipArray[0] = std::stoi(argv[3]);
flipArray[1] = std::stoi(argv[4]);
filter->SetFlipAxes(flipArray);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The input to the filter can be taken from any other filter, for example
// a reader. The output can be passed down the pipeline to other filters,
// for example, a writer. Invoking \code{Update()} on any downstream filter
// will trigger the execution of the FlipImage filter.
//
// \index{itk::FlipImageFilter!SetInput()}
// \index{itk::FlipImageFilter!GetOutput()}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
writer->SetInput(filter->GetOutput());
writer->Update();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// \begin{figure}
// \center
// \includegraphics[width=0.44\textwidth]{BrainProtonDensitySlice}
// \includegraphics[width=0.44\textwidth]{FlipImageFilterOutput}
// \itkcaption[Effect of the FlipImageFilter]{Effect of the FlipImageFilter
// on a slice from a MRI proton density brain image.}
// \label{fig:FlipImageFilterOutput}
// \end{figure}
//
// Figure \ref{fig:FlipImageFilterOutput} illustrates the effect of this
// filter on a slice of an MRI brain image using a flip array $[0,1]$ which
// means that the $Y$ axis was flipped while the $X$ axis was conserved.
//
// Software Guide : EndLatex
return EXIT_SUCCESS;
}
itkFlipImageFilter.h
itkImage.h
Data source that reads image data from a single file.