GDCM 2.2.1

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DecompressJPEGFile.cs

This is a C# example on how to use gdcm::SequenceOfFragments

/*=========================================================================
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.
=========================================================================*/
/*
* Usage:
* $ export LD_LIBRARY_PATH=$HOME/Projects/gdcm/debug-gcc/bin
* $ mono bin/DecompressJPEGFile.exe somejpegfile.jpg
*/
using System;
using gdcm;
public class DecompressJPEGFile
{
public static int Main(string[] args)
{
string file1 = args[0];
System.IO.FileStream infile =
new System.IO.FileStream(file1, System.IO.FileMode.Open, System.IO.FileAccess.Read);
uint fsize = gdcm.PosixEmulation.FileSize(file1);
byte[] jstream = new byte[fsize];
infile.Read(jstream, 0 , jstream.Length);
Trace.DebugOn();
Image image = new Image();
image.SetNumberOfDimensions( 2 ); // important for now
DataElement pixeldata = new DataElement( new gdcm.Tag(0x7fe0,0x0010) );
// DO NOT set a ByteValue here, JPEG is a particular kind of encapsulated syntax
// in which can one cannot use a simple byte array for storage. Instead, see
// gdcm.SequenceOfFragments
//pixeldata.SetByteValue( jstream, new gdcm.VL( (uint)jstream.Length ) );
// Create a new SequenceOfFragments C++ object, store it as a SmartPointer :
SmartPtrFrag sq = SequenceOfFragments.New();
Fragment frag = new Fragment();
frag.SetByteValue( jstream, new gdcm.VL( (uint)jstream.Length) );
// Single file => single fragment
sq.AddFragment( frag );
// Pass by reference:
pixeldata.SetValue( sq.__ref__() );
// insert:
image.SetDataElement( pixeldata );
// JPEG use YBR to achieve better compression ratio by default (not RGB)
// FIXME hardcoded:
PhotometricInterpretation pi = new PhotometricInterpretation( PhotometricInterpretation.PIType.YBR_FULL );
image.SetPhotometricInterpretation( pi );
// FIXME hardcoded:
PixelFormat pixeltype = new PixelFormat(3,8,8,7);
image.SetPixelFormat( pixeltype );
// FIXME hardcoded:
image.SetTransferSyntax( new TransferSyntax( TransferSyntax.TSType.JPEGLosslessProcess14_1 ) );
image.SetDimension(0, 692);
image.SetDimension(1, 721);
// Decompress !
byte[] decompressedData = new byte[(int)image.GetBufferLength()];
image.GetBuffer(decompressedData);
// Write out the decompressed bytes
System.Console.WriteLine(image.toString());
using (System.IO.Stream stream =
System.IO.File.Open(@"/tmp/dd.raw",
System.IO.FileMode.Create))
{
System.IO.BinaryWriter writer = new System.IO.BinaryWriter(stream);
writer.Write(decompressedData);
}
return 0;
}
}