[vtkusers] [Gdcm2] Matching CT and RT dose coordinates

[Mathieu Malaterre]

On Fri, Feb 25, 2011 at 4:45 PM, Jothy <jothybasu at gmail.com> wrote:
> from gdcm docs
>
> "DataOrigin:When the reader is instanciated with FileLowerLeftOn the
> DataOrigin and Image Position (Patient) are identical. But when
> FileLowerLeft is Off, we have to reorder the Y-line of the image, and thus
> the DataOrigin is then translated to the other side of the image."From
> these, I feel the vtkGDCMImageReader flips the image and recalculates the
> data origin.
> And it also seems to flip the  X & Y. When I set the position of dose actors
> as setPosition(ImagePositionPatientct[0],ImagePositionPatientdose[0] it
> exactly matches.
>
> Does anyone have a beeter understanding of this?

You have to turn the FileLowerLeft before calling update to preserve
DICOM coordinate system. eg.

reader->FileLowerLeftOn();
reader->Update();

HTH
-- 
Mathieu