ITK 重采样 resample

Itk 重新采样有二多种情况，这里说二种情况

1. 输入参数，和输出相关数据，输出范围，spacing ；

	typedef itk::Image< float, 3 > itkFloatImageType;

	typedef itk::ResampleImageFilter < itkFloatImageType, itkFloatImageType > ResampleImageFilter;
	ResampleImageFilter::Pointer resampleImageFilter = ResampleImageFilter::New();
	typedef itk::LinearInterpolateImageFunction<itkFloatImageType, double> T_Interpolator;
	itkFloatImageType::Pointer itkImage;
	mitk::CastToItkImage(inputImage, itkImage);

	itkFloatImageType::Pointer itkImageOut;
	mitk::CastToItkImage(segmentationA, itkImageOut);

	itkFloatImageType::SpacingType outputSpacingItk = itkImageOut->GetSpacing();
	itkFloatImageType::SizeType outputSizeItk = itkImageOut->GetLargestPossibleRegion().GetSize();
  
	typedef itk::IdentityTransform<double, 3> TransformType;
	T_Interpolator::Pointer _pInterpolator = T_Interpolator::New();
	resampleImageFilter->SetInput(itkImage);
 
	resampleImageFilter->SetTransform(TransformType::New());
	resampleImageFilter->SetInterpolator(_pInterpolator);
	resampleImageFilter->SetReferenceImage(itkImageOut);
	resampleImageFilter->UseReferenceImageOn();
	//resampleImageFilter->UpdateLargestPossibleRegion();
	resampleImageFilter->Update();

注意输入是 float

其它类型转 to float

vtkImageData *  ToFloatScaleValue(vtkImageData * VtkImageData)
{
 
	 Thresholding
	vtkSmartPointer<vtkImageThreshold> imageThreshold = vtkSmartPointer<vtkImageThreshold>::New();
	imageThreshold->SetInputData(VtkImageData);
	imageThreshold->SetOutputScalarTypeToFloat();

	imageThreshold->ThresholdByLower(0.2); // range is inclusive but always in double. Precision issue.
	imageThreshold->SetOutValue(255);
	imageThreshold->SetInValue(0);
	imageThreshold->ReleaseDataFlagOn();
	imageThreshold->UpdateInformation();
	imageThreshold->Update();
 

	return imageThreshold->GetOutput();
 }

2. 输入参数 ,输入数据，和输出相关数据， spacing ；需要自己求出 bounds 输出范围

 typedef itk::ResampleImageFilter < itkFloatImageType, itkFloatImageType > ResampleImageFilter;
    ResampleImageFilter::Pointer resampleImageFilter = ResampleImageFilter::New();

    itkFloatImageType::Pointer itkImage;
    mitk::CastToItkImage(out, itkImage);
    itkFloatImageType::SpacingType outputSpacing;
    itkFloatImageType::SizeType inputSize = itkImage->GetLargestPossibleRegion().GetSize();
    itkFloatImageType::SizeType outputSize = inputSize;

    outputSpacing[0] = itkImage->GetSpacing()[0];
    outputSpacing[1] = resampleSpacing;
    outputSpacing[2] = itkImage->GetSpacing()[2];

    outputSize[1] = inputSize[1] * itkImage->GetSpacing()[1] / outputSpacing[1];

    typedef itk::IdentityTransform<double, 3> TransformType;
    resampleImageFilter->SetInput(itkImage);
    resampleImageFilter->SetSize(outputSize);
    resampleImageFilter->SetOutputSpacing(outputSpacing);
    resampleImageFilter->SetTransform(TransformType::New());

    resampleImageFilter->UpdateLargestPossibleRegion();