double
mitk::SortByImagePositionPatient
::InternalNumericDistance(const mitk::DICOMDatasetAccess* left, const mitk::DICOMDatasetAccess* right, bool& possible) const
{
// sort by distance to world origin, assuming (almost) equal orientation
static const DICOMTag tagImagePositionPatient = DICOMTag(0x0020,0x0032); // Image Position (Patient)
static const DICOMTag tagImageOrientation = DICOMTag(0x0020, 0x0037); // Image Orientation
Vector3D leftRight; leftRight.Fill(0.0);
Vector3D leftUp; leftUp.Fill(0.0);
bool leftHasOrientation(false);
DICOMStringToOrientationVectors( left->GetTagValueAsString( tagImageOrientation ).value,
leftRight, leftUp, leftHasOrientation );
Vector3D rightRight; rightRight.Fill(0.0);
Vector3D rightUp; rightUp.Fill(0.0);
bool rightHasOrientation(false);
DICOMStringToOrientationVectors(right->GetTagValueAsString(tagImageOrientation).value,
rightRight, rightUp, rightHasOrientation );
Point3D leftOrigin; leftOrigin.Fill(0.0f);
bool leftHasOrigin(false);
leftOrigin = DICOMStringToPoint3D(left->GetTagValueAsString(tagImagePositionPatient).value, leftHasOrigin);
Point3D rightOrigin; rightOrigin.Fill(0.0f);
bool rightHasOrigin(false);
rightOrigin = DICOMStringToPoint3D(right->GetTagValueAsString(tagImagePositionPatient).value, rightHasOrigin);
// we tolerate very small differences in image orientation, since we got to know about
// acquisitions where these values change across a single series (7th decimal digit)
// (http://bugs.mitk.org/show_bug.cgi?id=12263)
// still, we want to check if our assumption of 'almost equal' orientations is valid
for (unsigned int dim = 0; dim < 3; ++dim)
{
if ( fabs(leftRight[dim] - rightRight[dim]) > 0.0001
|| fabs(leftUp[dim] - rightUp[dim]) > 0.0001)
{
MITK_ERROR << "Dicom images have different orientations.";
throw std::logic_error("Dicom images have different orientations. Call GetSeries() first to separate images.");
}
}
Vector3D normal;
normal[0] = leftRight[1] * leftUp[2] - leftRight[2] * leftUp[1];
normal[1] = leftRight[2] * leftUp[0] - leftRight[0] * leftUp[2];
normal[2] = leftRight[0] * leftUp[1] - leftRight[1] * leftUp[0];
double leftDistance = 0.0;
double rightDistance = 0.0;
// this computes the distance from world origin (0,0,0) ALONG THE NORMAL of the image planes
for (unsigned int dim = 0; dim < 3; ++dim)
{
leftDistance += normal[dim] * leftOrigin[dim];
rightDistance += normal[dim] * rightOrigin[dim];
}
// if we can sort by just comparing the distance, we do exactly that
if ( fabs(leftDistance - rightDistance) >= mitk::eps)
{
possible = true;
// default: compare position
return rightDistance - leftDistance; // if (left < right> ==> diff > 0
}
else
{
possible = false;
return 0.0;
}
}
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...
std::string imageOrientationString = firstDS->GetTagValueAsString( tagImageOrientation );
std::string imagePositionPatientFirst = firstDS->GetTagValueAsString( tagImagePositionPatient );
std::string imagePositionPatientLast = lastDS->GetTagValueAsString( tagImagePositionPatient );
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;
if ( projection < 0.0 )
{
MITK_DEBUG << "Need to reverse filenames";
std::reverse( datasets.begin(), datasets.end() );
m_TiltInfo = GantryTiltInformation::MakeFromTagValues(
imagePositionPatientLast,
imagePositionPatientFirst,
imageOrientationString,
datasets.size() - 1
);
}
else
{
m_TiltInfo = GantryTiltInformation::MakeFromTagValues(
imagePositionPatientFirst,
imagePositionPatientLast,
imageOrientationString,
datasets.size() - 1
);
}
}
else // just ONE dataset, do not forget to reset tilt information
{
m_TiltInfo = GantryTiltInformation(); // empty info
}
this->SetNumberOfOutputs(1);
this->SetOutput(0, datasets);
}