Method Sort

Modules/DICOM/src/mitkNormalDirectionConsistencySorter.cpp:74–162

}

void
mitk::NormalDirectionConsistencySorter
::Sort()
{
  DICOMDatasetList datasets = GetInput();

  if (datasets.size() > 1)
  {
    // at some point in the code, there is the expectation that
    // the direction of the slice normals is the same as the direction between
    // first and last slice origin. We need to make this sure here, because
    // we want to feed the files into itk::ImageSeriesReader with the consistent
    // setting of ReverseOrderOff.

    static const DICOMTag tagImagePositionPatient = DICOMTag(0x0020,0x0032); // Image Position (Patient)
    static const DICOMTag    tagImageOrientation = DICOMTag(0x0020, 0x0037); // Image Orientation

    DICOMDatasetAccess* firstDS = datasets.front();
    DICOMDatasetAccess*  lastDS = datasets.back();

    // make sure here that the direction from slice to slice is the direction of
    // image normals...
    const std::string imageOrientationString = firstDS->GetTagValueAsString( tagImageOrientation ).value;
    const std::string imagePositionPatientFirst = firstDS->GetTagValueAsString(tagImagePositionPatient).value;
    const std::string imagePositionPatientLast = lastDS->GetTagValueAsString(tagImagePositionPatient).value;

    Vector3D right; right.Fill(0.0);
    Vector3D up; up.Fill(0.0);
    bool hasOrientation(false);
    DICOMStringToOrientationVectors( imageOrientationString,
        right, up, hasOrientation );

    Point3D firstOrigin; firstOrigin.Fill(0.0f);
    bool firstHasOrigin(false);
    firstOrigin = DICOMStringToPoint3D( imagePositionPatientFirst, firstHasOrigin );

    Point3D lastOrigin; lastOrigin.Fill(0.0f);
    bool lastHasOrigin(false);
    lastOrigin = DICOMStringToPoint3D( imagePositionPatientLast, lastHasOrigin );

    Vector3D normal;
    normal[0] = right[1] * up[2] - right[2] * up[1];
    normal[1] = right[2] * up[0] - right[0] * up[2];
    normal[2] = right[0] * up[1] - right[1] * up[0];
    normal.Normalize();

    Vector3D directionOfSlices;
    directionOfSlices = lastOrigin - firstOrigin;
    directionOfSlices.Normalize();

    double projection = normal * directionOfSlices;

    MITK_DEBUG << "Making sense of \norientation '" << imageOrientationString
               << "'\nfirst position '" << imagePositionPatientFirst
               << "'\nlast position '" << imagePositionPatientLast << "'";
    MITK_DEBUG << "Normal: " << normal;
    MITK_DEBUG << "Direction of slices: " << directionOfSlices;
    MITK_DEBUG << "Projection of direction onto slice normal: " << projection;