void RunRegistration() {
_transform = TransformType::New();
OptiReporter::Pointer optiReporter = OptiReporter::New();
Metric::Pointer metric = Metric::New();
metric->SetFixedImage(_dst);
bool useIndexes = false;
if (useIndexes) {
_centerOfRotation.SetSize(ImageType::ImageDimension);
for (int i = 0; i < ImageType::ImageDimension; i++) {
_centerOfRotation[i] = i;
}
itk::ImageRegionConstIteratorWithIndex<LabelType> labelIter(_dstLabel, _dstLabel->GetBufferedRegion());
int nPixels = 0;
for (labelIter.GoToBegin(); !labelIter.IsAtEnd(); ++labelIter) {
LabelType::PixelType label = labelIter.Get();
if (label > 0) {
_labelIndexes.push_back(labelIter.GetIndex());
for (int i = 0; i < ImageType::ImageDimension; i++) {
_centerOfRotation[i] += labelIter.GetIndex()[i];
}
nPixels ++;
}
}
for (int i = 0; i < ImageType::ImageDimension; i++) {
_centerOfRotation[i] /= nPixels;
}
metric->SetFixedImageIndexes(_labelIndexes);
_transform->SetFixedParameters(_centerOfRotation);
} else {
metric->SetFixedImageRegion(_dst->GetBufferedRegion());
metric->SetUseAllPixels(true);
_centerOfRotation.SetSize(ImageType::ImageDimension);
for (int i = 0; i < 3; i++) {
_centerOfRotation[i] = _dstCenter[i];
}
_transform->SetFixedParameters(_centerOfRotation);
}
cout << "Fixed Parameters: " << _centerOfRotation << endl;
metric->SetMovingImage(_src);
metric->SetInterpolator(Interpolator::New());
metric->SetTransform(_transform);
metric->Initialize();
Optimizer::Pointer opti = Optimizer::New();
opti->SetCostFunction(metric);
Optimizer::ScalesType scales;
scales.SetSize(TransformType::ParametersDimension);
scales.Fill(1);
if (_method == "affine") {
cout << "apply affine scaling ..." << endl;
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
if (i == j) {
scales[3*i+j] = 160;
} else {
scales[3*i+j] = 30;
}
}
}
scales[9] = scales[10] = scales[11] = 0.1;
} else if (_method == "scale") {
scales[0] = scales[1] = scales[2] = 30;
scales[3] = scales[4] = scales[5] = .5;
scales[6] = scales[7] = scales[8] = 100;
} else if (_method == "similar") {
scales[0] = scales[1] = scales[2] = 10;
scales[3] = scales[4] = scales[5] = 0.5;
scales[6] = 100;
}
opti->SetScales(scales);
const int maxIters = 100;
#ifdef USE_CG_OPTIMIZER
opti->SetMaximumIteration(maxIters);
opti->SetMaximumLineIteration(10);
opti->SetUseUnitLengthGradient(true);
opti->SetStepLength(1);
opti->SetToFletchReeves();
#endif
#ifdef USE_GD_OPTIMIZER
opti->SetNumberOfIterations(maxIters);
opti->SetMinimumStepLength(1e-4);
opti->SetMaximumStepLength(3);
opti->SetRelaxationFactor(.5);
opti->SetGradientMagnitudeTolerance(1e-4);
#endif
opti->SetInitialPosition(_transform->GetParameters());
opti->AddObserver(itk::StartEvent(), optiReporter);
opti->AddObserver(itk::IterationEvent(), optiReporter);
opti->StartOptimization();
cout << "Current Cost: " << opti->GetValue() << endl;
_transformResult = opti->GetCurrentPosition();
_transform->SetParameters(opti->GetCurrentPosition());
}
