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/*=========================================================================
Program: GDCM (Grassroots DICOM). A DICOM library
Copyright (c) 2006-2011 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 rewrite a ELSCINT1/PMSCT_RLE1 compressed
* image so that it is readable by most 3rd party software (DICOM does
* not specify this particular encoding).
* This is required for the sake of interoperability with any standard
* conforming DICOM system.
*
* Everything done in this code is for the sole purpose of writing interoperable
* software under Sect. 1201 (f) Reverse Engineering exception of the DMCA.
* If you believe anything in this code violates any law or any of your rights,
* please contact us (gdcm-developers@lists.sourceforge.net) so that we can
* find a solution.
*
* Everything you do with this code is at your own risk, since decompression
* algorithm was not written from specification documents.
*
* Special thanks to:
* Mauro Maiorca for bringing to our attention on this new ELSCINT1
* compression algorithm : PMSCT_RLE1 (different from the 'LOSSLESS RICE')
* See post at:
* http://groups.google.com/group/comp.protocols.dicom/msg/f2b99bf706a7f8ca
*
* Thanks to Jesus Spinola, for more datasets,
* http://www.itk.org/pipermail/insight-users/2008-April/025571.html
*
* And last but not least, a very big thank to Ivo van Poorten, without
* whom we would still be looking at this compressed byte stream as if
* it was RLE compressed.
*/
#include "gdcmReader.h"
#include "gdcmPrivateTag.h"
#include "gdcmAttribute.h"
#include "gdcmImageWriter.h"
/* FIXME: Why is PhilipsLosslessRice.dcm a 512x512 image ... */
void delta_decode(const char *inbuffer, size_t length, std::vector<unsigned short> &output)
{
// RLE pass
std::vector<char> temp;
for(size_t i = 0; i < length; ++i)
{
if( inbuffer[i] == (char)0xa5 )
{
//unsigned char repeat = (unsigned char)inbuffer[i+1] + 1;
//assert( (unsigned char)inbuffer[i+1] != 255 );
int repeat = (unsigned char)inbuffer[i+1] + 1;
char value = inbuffer[i+2];
while(repeat)
{
temp.push_back( value );
--repeat;
}
i+=2;
}
else
{
temp.push_back( inbuffer[i] );
}
}
// Delta encoding pass
unsigned short delta = 0;
for(size_t i = 0; i < temp.size(); ++i)
{
if( temp[i] == 0x5a )
{
unsigned char v1 = (unsigned char)temp[i+1];
unsigned char v2 = (unsigned char)temp[i+2];
unsigned short value = (unsigned short)(v2 * 256 + v1);
output.push_back( value );
delta = value;
i+=2;
}
else
{
unsigned short value = (unsigned short)(temp[i] + delta);
output.push_back( value );
delta = value;
}
//assert( output[output.size()-1] == ref[output.size()-1] );
}
if ( output.size() % 2 )
{
output.resize( output.size() - 1 );
}
std::cout << length << " -> " << output.size() * 2 << std::endl;
}
int main(int argc, char *argv [])
{
if( argc < 2 )
{
std::cerr << argv[0] << "input.dcm [output.dcm]" << std::endl;
std::cerr << "will default to 'outrle.dcm' unless output.dcm is specified."
<< std::endl;
return 1;
}
const char *filename = argv[1];
gdcm::Reader reader;
reader.SetFileName( filename );
if( !reader.Read() )
{
std::cerr << "Failed to read: " << filename << std::endl;
return 1;
}
const gdcm::DataSet& ds = reader.GetFile().GetDataSet();
// (07a1,1011) CS [PMSCT_RLE1] # 10,1 Tamar Compression Type
const gdcm::PrivateTag tcompressiontype(0x07a1,0x0011,"ELSCINT1");
if( !ds.FindDataElement( tcompressiontype ) ) return 1;
const gdcm::DataElement& compressiontype = ds.GetDataElement( tcompressiontype );
if ( compressiontype.IsEmpty() ) return 1;
const gdcm::ByteValue * bv = compressiontype.GetByteValue();
std::string comprle = "PMSCT_RLE1";
std::string comprgb = "PMSCT_RGB1";
bool isrle = false;
bool isrgb = false;
if( strncmp( bv->GetPointer(), comprle.c_str(), comprle.size() ) == 0 )
{
isrle = true;
}
if( strncmp( bv->GetPointer(), comprgb.c_str(), comprgb.size() ) == 0 )
{
isrgb = true;
std::cerr << "See: pmsct_rgb1.cxx instead" << std::endl;
return 1;
}
if( !isrgb && !isrle ) return 1;
const gdcm::PrivateTag tcompressedpixeldata(0x07a1,0x000a,"ELSCINT1");
if( !ds.FindDataElement( tcompressedpixeldata) ) return 1;
const gdcm::DataElement& compressionpixeldata = ds.GetDataElement( tcompressedpixeldata);
if ( compressionpixeldata.IsEmpty() ) return 1;
const gdcm::ByteValue * bv2 = compressionpixeldata.GetByteValue();
gdcm::Attribute<0x0028,0x0010> at1;
at1.SetFromDataSet( ds );
gdcm::Attribute<0x0028,0x0011> at2;
at2.SetFromDataSet( ds );
gdcm::DataElement pixeldata( gdcm::Tag(0x7fe0,0x0010) );
pixeldata.SetVR( gdcm::VR::OW );
gdcm::VL bv2l = bv2->GetLength();
gdcm::VL at1l = at1.GetValue() * at2.GetValue() * 2; /* sizeof(unsigned short) == 2 */
// Handle special case that is not compressed:
if( bv2l == at1l )
{
pixeldata.SetByteValue( bv2->GetPointer(), bv2->GetLength() );
}
else
{
std::vector<unsigned short> buffer;
delta_decode(bv2->GetPointer(), bv2->GetLength(), buffer);
pixeldata.SetByteValue( (char*)&buffer[0], (uint32_t)(buffer.size() * sizeof( unsigned short )) );
}
// TODO we should check that decompress byte buffer match the expected size (row*col*...)
// Add the pixel data element
reader.GetFile().GetDataSet().Replace( pixeldata );
reader.GetFile().GetHeader().SetDataSetTransferSyntax(
gdcm::TransferSyntax::ExplicitVRLittleEndian);
gdcm::Writer writer;
writer.SetFile( reader.GetFile() );
// Cleanup stuff:
// remove the compressed pixel data:
// FIXME: should I remove more private tags ? all of them ?
// oh well this is just an example
// use gdcm::Anonymizer::RemovePrivateTags if needed...
writer.GetFile().GetDataSet().Remove( compressionpixeldata.GetTag() );
std::string outfilename;
if (argc > 2)
outfilename = argv[2];
else
outfilename = "outrle.dcm";
writer.SetFileName( outfilename.c_str() );
if( !writer.Write() )
{
std::cerr << "Failed to write" << std::endl;
return 1;
}
std::cout << "success !" << std::endl;
return 0;
}
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