/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: ImageReadWrite.cxx,v $
  Language:  C++
  Date:      $Date: 2006/05/10 20:27:17 $
  Version:   $Revision: 1.19 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#if defined(_MSC_VER)
#pragma warning ( disable : 4786 )
#endif

#ifdef __BORLANDC__
#define ITK_LEAN_AND_MEAN
#endif

//  Software Guide : BeginLatex
//
//  The classes responsible for reading and writing images are located at the
//  beginning and end of the data processing pipeline. These classes are
//  known as data sources (readers) and data sinks (writers).
//  Generally speaking they are referred to as filters, although readers have
//  no pipeline input and writers have no pipeline output.
//
//  The reading of images is managed by the class \doxygen{ImageFileReader}
//  while writing is performed by the class \doxygen{ImageFileWriter}. These
//  two classes are independent of any particular file format. The actual low
//  level task of reading and writing specific file formats is done behind
//  the scenes by a family of classes of type \doxygen{ImageIO}.
//
//  The first step for performing reading and writing is to include the
//  following headers.
//
//  \index{itk::ImageFileReader|textbf}
//  \index{itk::ImageFileReader!header}
//
//  \index{itk::ImageFileWriter|textbf}
//  \index{itk::ImageFileWriter!header}
//
//  Software Guide : EndLatex

// Software Guide : BeginCodeSnippet
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
// Software Guide : EndCodeSnippet


#include "itkImage.h"


int main( int argc, char ** argv )
{
  // Verify the number of parameters in the command line
  if( argc < 3 )
    {
    std::cerr << "Usage: " << std::endl;
    std::cerr << argv[0] << " inputImageFile  outputImageFile " << std::endl;
    return EXIT_FAILURE;
    }


  //  Software Guide : BeginLatex
  //
  //  Then, as usual, a decision must be made about the type of pixel used to
  //  represent the image processed by the pipeline. Note that when reading
  //  and writing images, the pixel type of the image \textbf{is not
  //  necessarily} the same as the pixel type stored in the file.  Your
  //  choice of the pixel type (and hence template parameter) should be
  //  driven mainly by two considerations:
  //
  //  \begin{itemize}
  //  \item It should be possible to cast the file pixel type in the file to
  //  the pixel type you select. This casting will be performed using the
  //  standard C-language rules, so you will have to make sure that the
  //  conversion does not result in information being lost.
  //  \item The pixel type in memory should be appropriate to the type of
  //  processing you intended to apply on the images. 
  //  \end{itemize}
  //
  //  A typical selection for medical images is illustrated in
  //  the following lines.
  //
  //  Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  typedef short      PixelType;
  const   unsigned int        Dimension = 2;
  typedef itk::Image< PixelType, Dimension >    ImageType;
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  Note that the dimension of the image in memory should match the one of
  //  the image in file. There are a couple of special cases in which this
  //  condition may be relaxed, but in general it is better to ensure that both
  //  dimensions match.
  //
  //  We can now instantiate the types of the reader and writer. These two
  //  classes are parameterized over the image type.
  //
  //  \index{itk::ImageFileReader!Instantiation}
  //  \index{itk::ImageFileWriter!Instantiation}
  //
  //  Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  typedef itk::ImageFileReader< ImageType >  ReaderType;
  typedef itk::ImageFileWriter< ImageType >  WriterType;
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  Then, we create one object of each type using the New() method and
  //  assigning the result to a \doxygen{SmartPointer}.
  //
  //  \index{itk::ImageFileReader!New()}
  //  \index{itk::ImageFileWriter!New()}
  //  \index{itk::ImageFileReader!SmartPointer}
  //  \index{itk::ImageFileWriter!SmartPointer}
  //
  //  Software Guide : EndLatex 

  // Software Guide : BeginCodeSnippet
  ReaderType::Pointer reader = ReaderType::New();
  WriterType::Pointer writer = WriterType::New();
  // Software Guide : EndCodeSnippet


  // Here we recover the file names from the command line arguments
  //
  const char * inputFilename  = argv[1];
  const char * outputFilename = argv[2];


  //  Software Guide : BeginLatex
  //
  //  The name of the file to be read or written is passed with the
  //  SetFileName() method. 
  //
  //  \index{itk::ImageFileReader!SetFileName()}
  //  \index{itk::ImageFileWriter!SetFileName()}
  //  \index{SetFileName()!itk::ImageFileReader}
  //  \index{SetFileName()!itk::ImageFileWriter}
  //
  //  Software Guide : EndLatex 

  // Software Guide : BeginCodeSnippet
  reader->SetFileName( inputFilename  );
  writer->SetFileName( outputFilename );
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  We can now connect these readers and writers to filters to create a
  //  pipeline. For example, we can create a short pipeline by passing
  //  the output of the reader directly to the input of the writer.
  //
  //  Software Guide : EndLatex 

  // Software Guide : BeginCodeSnippet
  writer->SetInput( reader->GetOutput() );
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  At first view, this may seem as a quite useless program, but it is
  //  actually implementing a powerful file format conversion tool! The
  //  execution of the pipeline is triggered by the invocation of the
  //  \code{Update()} methods in one of the final objects. In this case, the final
  //  data pipeline object is the writer. It is a wise practice of defensive
  //  programming to insert any \code{Update()} call inside a \code{try/catch} block
  //  in case exceptions are thrown during the execution of the pipeline.
  //
  //  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


  //  Software Guide : BeginLatex
  //
  //  Note that exceptions should only be caught by pieces of code that know
  //  what to do with them. In a typical application this \code{catch} block
  //  should probably reside on the GUI code. The action on the \code{catch}
  //  block could inform the user about the failure of the IO operation.
  //
  //  The IO architecture of the toolkit makes it possible to avoid explicit
  //  specification of the file format used to read or write
  //  images.\footnote{In this example no file format is specified; this
  //  program can be used as a general file conversion utility.}  The object
  //  factory mechanism enables the ImageFileReader and ImageFileWriter to
  //  determine (at run-time) with which file format it is working
  //  with. Typically, file formats are chosen based on the filename
  //  extension, but the architecture supports arbitrarily complex processes
  //  to determine whether a file can be read or written. Alternatively, the
  //  user can specify the data file format by explicit instantiation and
  //  assignment the appropriate \doxygen{ImageIO} subclass.
  //
  //  For historical reasons and as a convenience to the user, the
  //  \doxygen{ImageFileWriter} also has a Write() method that is aliased to
  //  the \code{Update()} method. You can in principle use either of them but
  //  \code{Update()} is recommended since Write() may be deprecated in the future.
  //
  //  Software Guide : EndLatex 

  return EXIT_SUCCESS;
}



