# CompressLossyJPEG.cs

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

      Program: GDCM (Grassroots DICOM). A DICOM library
      Module:  $URL$

      Copyright (c) 2006-2010 Mathieu Malaterre
      All rights reserved.
      See Copyright.txt or http://gdcm.sourceforge.net/Copyright.html 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 notice for more information.

    =========================================================================*/
    /*
     * Usage:
     * $ export LD_LIBRARY_PATH=$HOME/Perso/gdcm/debug-gcc/bin
     * $ mono bin/CompressLossyJPEG.exe input.dcm output.dcm
     */

    using System;
    using gdcm;

    public class CompressLossyJPEG
    {
      public static int Main(string[] args)
        {
        if( args.Length < 2 )
          {
          System.Console.WriteLine( " input.dcm output.dcm" );
          return 1;
          }
        string filename = args[0];
        string outfilename = args[1];

        ImageReader reader = new ImageReader();
        reader.SetFileName( filename );
        if( !reader.Read() )
          {
          System.Console.WriteLine( "Could not read: " + filename );
          return 1;
          }

        // The output of gdcm::Reader is a gdcm::File
        File file = reader.GetFile();

        // the dataset is the the set of element we are interested in:
        DataSet ds = file.GetDataSet();

        Image image = reader.GetImage();
        //image.Print( cout );

        ImageChangeTransferSyntax change = new ImageChangeTransferSyntax();
        TransferSyntax targetts =  new TransferSyntax( TransferSyntax.TSType.JPEGBaselineProcess1 );
        change.SetTransferSyntax( targetts );

        // Setup our JPEGCodec, warning it should be compatible with JPEGBaselineProcess1
        JPEGCodec jpegcodec = new JPEGCodec();
        if( !jpegcodec.CanCode( targetts ) )
          {
          System.Console.WriteLine( "Something went really wrong, JPEGCodec cannot handle JPEGBaselineProcess1" );
          return 1;
          }
        jpegcodec.SetLossless( false );
        jpegcodec.SetQuality( 50 ); // poor quality !
        change.SetUserCodec( jpegcodec ); // specify the codec to use to the ImageChangeTransferSyntax

        change.SetInput( image );
        bool b = change.Change();
        if( !b )
          {
          System.Console.WriteLine( "Could not change the Transfer Syntax" );
          return 1;
          }

        ImageWriter writer = new ImageWriter();
        writer.SetImage( change.GetOutput() );
        writer.SetFile( reader.GetFile() );
        writer.SetFileName( outfilename );
        if( !writer.Write() )
          {
          System.Console.WriteLine( "Could not write: " + outfilename );
          return 1;
          }

        return 0;
        }

    }