ITK  5.0.0
Insight Segmentation and Registration Toolkit
Examples/IO/ImageSeriesReadWrite.cxx
/*=========================================================================
*
* 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
//
// This example illustrates how to read a series of 2D slices from independent
// files in order to compose a volume. The class \doxygen{ImageSeriesReader}
// is used for this purpose. This class works in combination with a generator
// of filenames that will provide a list of files to be read. In this
// particular example we use the \doxygen{NumericSeriesFileNames} class as a
// filename generator. This generator uses a \code{printf} style of string format
// with a ``\code{\%d}'' field that will be successively replaced by a number specified
// by the user. Here we will use a format like ``\code{file\%03d.png}'' for reading
// PNG files named file001.png, file002.png, file003.png... and so on.
//
// This requires the following headers as shown.
//
// \index{itk::ImageSeriesReader!header}
// \index{itk::NumericSeriesFileNames!header}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
#include "itkImage.h"
#include "itkPNGImageIO.h"
// Software Guide : EndCodeSnippet
int main( int argc, char ** argv )
{
// Verify the number of parameters in the command line
if( argc < 4 )
{
std::cerr << "Usage: " << std::endl;
std::cerr << argv[0] << " firstSliceValue lastSliceValue outputImageFile " << std::endl;
return EXIT_FAILURE;
}
// Software Guide : BeginLatex
//
// We start by defining the \code{PixelType} and \code{ImageType}.
//
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using PixelType = unsigned char;
constexpr unsigned int Dimension = 3;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The image type is used as a template parameter to instantiate
// the reader and writer.
//
// \index{itk::ImageSeriesReader!Instantiation}
// \index{itk::ImageFileWriter!Instantiation}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
ReaderType::Pointer reader = ReaderType::New();
WriterType::Pointer writer = WriterType::New();
// Software Guide : EndCodeSnippet
const unsigned int first = std::stoi( argv[1] );
const unsigned int last = std::stoi( argv[2] );
const char * outputFilename = argv[3];
// Software Guide : BeginLatex
//
// Then, we declare the filename generator type and create one instance of it.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using NameGeneratorType = itk::NumericSeriesFileNames;
NameGeneratorType::Pointer nameGenerator = NameGeneratorType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The filename generator requires us to provide a pattern of text for the
// filenames, and numbers for the initial value, last value and increment to be
// used for generating the names of the files.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
nameGenerator->SetSeriesFormat( "vwe%03d.png" );
nameGenerator->SetStartIndex( first );
nameGenerator->SetEndIndex( last );
nameGenerator->SetIncrementIndex( 1 );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The ImageIO object that actually performs the read process is now connected
// to the ImageSeriesReader. This is the safest way of making sure that we use
// an ImageIO object that is appropriate for the type of files that we want to
// read.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
reader->SetImageIO( itk::PNGImageIO::New() );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The filenames of the input files must be provided to the reader, while the
// writer is instructed to write the same volume dataset in a single file.
//
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
reader->SetFileNames( nameGenerator->GetFileNames() );
writer->SetFileName( outputFilename );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We connect the output of the reader to the input of the writer.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
writer->SetInput( reader->GetOutput() );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Finally, execution of the pipeline can be triggered by invoking the
// \code{Update()} method in the writer. This call must be placed in a
// \code{try/catch} block since exceptions be potentially be thrown in the
// process of reading or writing the images.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
try
{
writer->Update();
}
catch( itk::ExceptionObject & err )
{
std::cerr << "ExceptionObject caught !" << std::endl;
std::cerr << err << std::endl;
return EXIT_FAILURE;
}
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}