使用 Reconstruction Toolkit 去伪影的c++代码

这里提供一个基于 Reconstruction Toolkit (RTK) 的 C++ 代码，用于去除伪影：

#include <rtkForwardWarpBackProjectionImageFilter.h>
#include <rtkConstantImageSource.h>
#include <rtkFDKConeBeamReconstructionFilter.h>
#include <rtkThreeDCircularProjectionGeometry.h>
#include <rtkCyclicDeformationImageFilter.h>
#include <rtkDisplacedDetectorImageFilter.h>
#include <rtkLagCorrectionImageFilter.h>

// Define types
typedef float OutputPixelType;
const unsigned int Dimension = 3;
typedef itk::Image< OutputPixelType, Dimension > OutputImageType;

// Create and set geometry
rtk::ThreeDCircularProjectionGeometry::Pointer geometry = rtk::ThreeDCircularProjectionGeometry::New();
// Set up projection geometry
// ...

// Create a reader for the input volume and the projection stack
// ...

// Create a forward projection filter
typedef rtk::FDKConeBeamReconstructionFilter< OutputImageType > FDKType;
FDKType::Pointer fdk = FDKType::New();
fdk->SetInputVolume(volumeReader->GetOutput());
fdk->SetInputProjectionStack(projectionReader->GetOutput());
fdk->SetGeometry(geometry);

// Create the forward warper
typedef rtk::ForwardWarpBackProjectionImageFilter<OutputImageType> WarperType;
WarperType::Pointer warper = WarperType::New();
warper->SetInput(fdk->GetOutput());
warper->SetInputVolume(volumeReader->GetOutput());
warper->SetDisplacementField(displacementFieldReader->GetOutput());
warper->SetGeometry(geometry);

// Create a constant image source for the displaced detector image
typedef rtk::ConstantImageSource< OutputImageType > ConstantImageSourceType;
ConstantImageSourceType::Pointer constantImageSource = ConstantImageSourceType::New();
constantImageSource->SetSize(fdk->GetOutput()->GetLargestPossibleRegion().GetSize());
constantImageSource->SetSpacing(fdk->GetOutput()->GetSpacing());
constantImageSource->SetOrigin(fdk->GetOutput()->GetOrigin());
constantImageSource->SetDirection(fdk->GetOutput()->GetDirection());
constantImageSource->SetConstant(0.);

// Create a filter for the displaced detector image
typedef rtk::DisplacedDetectorImageFilter< OutputImageType > DisplacedDetectorType;
DisplacedDetectorType::Pointer displacedDetector = DisplacedDetectorType::New();
displacedDetector->SetInput(constantImageSource->GetOutput());
displacedDetector->SetInputGeometry(geometry);
displacedDetector->SetDisplacementField(displacementFieldReader->GetOutput());

// Create a filter for cyclic deformation
typedef rtk::CyclicDeformationImageFilter< OutputImageType > CyclicDeformationType;
CyclicDeformationType::Pointer cyclicDeformation = CyclicDeformationType::New();
cyclicDeformation->SetInput(displacedDetector->GetOutput());
cyclicDeformation->SetGeometry(geometry);

// Create a filter for lag correction
typedef rtk::LagCorrectionImageFilter< OutputImageType > LagCorrectionType;
LagCorrectionType::Pointer lagCorrection = LagCorrectionType::New();
lagCorrection->SetInput(warper->GetOutput());
lagCorrection->SetInputReference(cyclicDeformation->GetOutput());
lagCorrection->SetGeometry(geometry);

// Set up and run the pipeline
// ...

// Write the output volume
// ...

这里的代码中，我们使用了 RTK 中的几个滤波器，分别是：

- `rtk::FDKConeBeamReconstructionFilter`: 用于重建 CT 体数据的 FDK 滤波器。
- `rtk::ForwardWarpBackProjectionImageFilter`: 用于前向投影和反向投影的滤波器，它将重建后的体数据通过使用位移场进行前向变形，然后进行投影，最后再通过反向变形将投影像素值反投影回体数据中。
- `rtk::ConstantImageSource`: 用于创建一个常数图像。
- `rtk::DisplacedDetectorImageFilter`: 用于模拟位移场对探测器位置的影响。
- `rtk::CyclicDeformationImageFilter`: 用于模拟探测器的周期性变形。
- `rtk::LagCorrectionImageFilter`: 用于修正探测器的滞后效应。

这些滤波器的具体用法和参数设置可以参考 RTK 的文档。