# ConvertToQImage.cxx

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

      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.

    =========================================================================*/
    /*
     * This example shows how to setup the pipeline from a gdcm::ImageReader into a
     * Qt QImage data structure.
     * It only handles 2D image.
     *
     * Ref:
     * http://doc.trolltech.com/4.5/qimage.html
     *
     * Usage:
     *  ConvertToQImage gdcmData/012345.002.050.dcm output.png

     * Thanks:
     *   Sylvain ADAM (sylvain51 hotmail com) for contributing this example
     */

    #include "gdcmImageReader.h"
    #include <QImage>
    #include <QImageWriter>

    bool ConvertToFormat_RGB888(gdcm::Image const & gimage, char *buffer, QImage* &imageQt)
    {
      const unsigned int* dimension = gimage.GetDimensions();

      unsigned int dimX = dimension[0];
      unsigned int dimY = dimension[1];

      gimage.GetBuffer(buffer);

      // Let's start with the easy case:
      if( gimage.GetPhotometricInterpretation() == gdcm::PhotometricInterpretation::RGB )
        {
        if( gimage.GetPixelFormat() != gdcm::PixelFormat::UINT8 )
          {
          return false;
          }
        unsigned char *ubuffer = (unsigned char*)buffer;
        // QImage::Format_RGB888  13  The image is stored using a 24-bit RGB format (8-8-8).
        imageQt = new QImage(ubuffer, dimX, dimY, QImage::Format_RGB888);
        }
      else if( gimage.GetPhotometricInterpretation() == gdcm::PhotometricInterpretation::MONOCHROME2 )
        {
        if( gimage.GetPixelFormat() == gdcm::PixelFormat::UINT8 )
          {
          // We need to copy each individual 8bits into R / G and B:
          unsigned char *ubuffer = new unsigned char[dimX*dimY*3];
          unsigned char *pubuffer = ubuffer;
          for(int i = 0; i < dimX*dimY; i++)
            {
            *pubuffer++ = *buffer;
            *pubuffer++ = *buffer;
            *pubuffer++ = *buffer++;
            }

          imageQt = new QImage(ubuffer, dimX, dimY, QImage::Format_RGB888);
          }
        else if( gimage.GetPixelFormat() == gdcm::PixelFormat::INT16 )
          {
          // We need to copy each individual 16bits into R / G and B (truncate value)
          short *buffer16 = (short*)buffer;
          unsigned char *ubuffer = new unsigned char[dimX*dimY*3];
          unsigned char *pubuffer = ubuffer;
          for(int i = 0; i < dimX*dimY; i++)
            {
            // Scalar Range of gdcmData/012345.002.050.dcm is [0,192], we could simply do:
            // *pubuffer++ = *buffer16;
            // *pubuffer++ = *buffer16;
            // *pubuffer++ = *buffer16;
            *pubuffer++ = *buffer16 / 256;
            *pubuffer++ = *buffer16 / 256;
            *pubuffer++ = *buffer16 / 256;
            buffer16++;
            }

          imageQt = new QImage(ubuffer, dimX, dimY, QImage::Format_RGB888);
          }
        else
          {
          std::cerr << "Pixel Format is: " << gimage.GetPixelFormat() << std::endl;
          return false;
          }
        }
      else
        {
        std::cerr << "Unhandled PhotometricInterpretation: " << gimage.GetPhotometricInterpretation() << std::endl;
        return false;
        }

      return true;
    }

    int main(int argc, char *argv[])
    {
      if( argc < 2 )
        {
        return 1;
        }
      const char *filename = argv[1];
      const char *outfilename = argv[2];

      gdcm::ImageReader ir;
      ir.SetFileName( filename );
      if(!ir.Read())
        {
        //Read failed
        return 1;
        }

      std::cout<<"Getting image from ImageReader..."<<std::endl;

      const gdcm::Image &gimage = ir.GetImage();
      //This buffer has been declared elsewhere
      char *buffer = new char[gimage.GetBufferLength()];

      QImage *imageQt = NULL;
      if( !ConvertToFormat_RGB888( gimage, buffer, imageQt ) )
        {
        return 1;
        }

      QImageWriter writer;
      writer.setFormat("png");
      writer.setFileName( outfilename );
      if( !writer.write( *imageQt ) )
        {
        return 1;
        }

    //  delete[] buffer;

      return 0;
    }