[Insight-users] ImageWriter does not write Orientation (Direction Cosines)

[Bryn Lloyd]

Hi Bill, anybody!

I am working with images that have a variable orientation relative to
another image. Which is why I decided to use the itkOrientedImage class.
My problem is when I try to write the image. Somehow the orientation is
lost. I try to save the image using the meta-header format (.mhd).

Is this a bug or am I doing something wrong?

Thanks!

Bryn


--------------

the header looks like this

ObjectType = Image
NDims = 3
BinaryData = True
BinaryDataByteOrderMSB = False
TransformMatrix = 1 0 0 0 1 0 0 0 1
Offset = 0 0 0
CenterOfRotation = 0 0 0
AnatomicalOrientation = RSP
ElementSpacing = 0.859375 0.859375 5
DimSize = 256 256 1
ElementType = MET_DOUBLE
ElementDataFile = I020.raw


I would assume the TransformMatrix should contain the direction cosines!?

------------------

  const unsigned int Dimension = 3;
  typedef   double  PixelType;

  typedef itk::OrientedImage< PixelType,   Dimension >        ImageType;

  typedef itk::ImageFileReader< ImageType >      ReaderType;
  typedef itk::ImageFileWriter< ImageType >      WriterType;

  ReaderType::Pointer reader = ReaderType::New();
   reader->SetFileName( filenameGE5 );
   reader->Update();

 ImageType::Pointer image = reader->GetOutput();
  this->ReadHeader( filenameGE5 );


/* set direction cosines */

 typedef itk::Matrix<double,3,3>  DirectionType;
  DirectionType direction;
  direction.Fill(0.0);
  direction[0][0] = 1.0;   // 1 0 0
  direction[1][2] = 1.0;   // 0 0 1
  direction[2][1] = 1.0;   // 0 1 0


  std::cout << "New Direction Cosines " << std::endl << direction <<
std::endl;

  image->SetDirection(direction);
  std::cout << "Image Direction Cosines " << std::endl <<
image->GetDirection() << std::endl;


 WriterType::Pointer writer = WriterType::New();
  writer->SetInput( image );
  writer->SetFileName( filenameOut );
  writer->Update();