VTK读取DICOM医学图片进行体绘制的几种方法

注意的是：VTK中不同的vtkVolumeMapper支持不同的数据类型。比如vtkVolumeRayCastMapper和vtkVolumeTextureMapper2D只能支持单分组VTK_UNSIGNED_CHAR和VTK_UNSIGNED_SHORT类型数据，因此当读入其他类型的图像数据时，需要对数据进行转换，比如采用vtkImageCast或者vtkImageScale:而vtkVolumeTextMapper3D则支持任意数据类型，但是必须是单分组数据或者多元独立数据。vtkFixedPointVolumeRayCastMapper灵活性最高，可以支持所有类型数据，最高四元数据。

使用vtkFixedPointVolumeRayCastMapper类

#include "vtkRenderer.h"  #include "vtkRenderWindow.h"  #include "vtkRenderWindowInteractor.h"  #include "vtkActor.h"  #include "vtkSmartPointer.h"  #include "vtkProperty.h"  #include "vtkCamera.h"  #include "vtkDICOMImageReader.h"  #include "vtkImageCast.h"  #include "vtkPiecewiseFunction.h"  #include "vtkColorTransferFunction.h"  #include "vtkVolumeProperty.h"  #include "vtkVolumeRayCastCompositeFunction.h"  #include "vtkVolumeRayCastMapper.h"  #include "vtkVolume.h" #include "vtkAutoInit.h"#include "vtkFixedPointVolumeRayCastMapper.h"VTK_MODULE_INIT(vtkRenderingOpenGL);VTK_MODULE_INIT(vtkInteractionStyle);VTK_MODULE_INIT(vtkRenderingFreeType);VTK_MODULE_INIT(vtkRenderingVolumeOpenGL);int main(){    std::string str = "F:\\CT3";    vtkSmartPointer<vtkDICOMImageReader> reader = vtkSmartPointer<vtkDICOMImageReader>::New();    reader->SetDirectoryName(str.c_str());    reader->Update();    vtkSmartPointer<vtkPiecewiseFunction> opacityFun = vtkSmartPointer<vtkPiecewiseFunction>::New();    opacityFun->AddPoint(120,0.0);    opacityFun->AddPoint(250,1.0);    opacityFun->AddPoint(520,1.0);    opacityFun->AddPoint(650,0.0);    vtkSmartPointer<vtkColorTransferFunction> TransferFun = vtkSmartPointer<vtkColorTransferFunction>::New();    TransferFun->AddRGBPoint(120, 255 / 255.0, 98 / 255.0, 98 / 255.0);    TransferFun->AddRGBPoint(250, 255 / 255.0, 255 / 255.0, 180 / 255.0);    TransferFun->AddRGBPoint(520, 1.0, 1.0, 1.0);    TransferFun->AddRGBPoint(650, 1.0, 1.0, 1.0);    vtkSmartPointer<vtkPiecewiseFunction> grideFun = vtkSmartPointer<vtkPiecewiseFunction>::New();    grideFun->AddPoint(120, 2.0);    grideFun->AddPoint(250, 2.0);    grideFun->AddPoint(520, 0.1);    grideFun->AddPoint(650, 0.1);    vtkSmartPointer<vtkVolumeProperty> volumeProperty = vtkSmartPointer<vtkVolumeProperty>::New();    volumeProperty->SetColor(TransferFun);    volumeProperty->SetScalarOpacity(opacityFun);    volumeProperty->SetGradientOpacity(grideFun);    volumeProperty->ShadeOn();    volumeProperty->SetAmbient(0.2);    volumeProperty->SetDiffuse(0.9);    volumeProperty->SetSpecular(0.2);    volumeProperty->SetSpecularPower(10);    vtkSmartPointer<vtkVolumeRayCastCompositeFunction> rayCastFun = vtkSmartPointer<vtkVolumeRayCastCompositeFunction>::New();    vtkSmartPointer<vtkFixedPointVolumeRayCastMapper> mapper1 = vtkSmartPointer<vtkFixedPointVolumeRayCastMapper>::New();    mapper1->SetInputConnection(reader->GetOutputPort());    mapper1->SetAutoAdjustSampleDistances(0);    vtkSmartPointer<vtkVolume> volume = vtkSmartPointer<vtkVolume>::New();    volume->SetMapper(mapper1);    volume->SetProperty(volumeProperty);    vtkSmartPointer<vtkRenderer> ren = vtkSmartPointer<vtkRenderer>::New();    ren->AddVolume(volume);    ren->SetBackground(1.0,1.0,1.0);    vtkSmartPointer<vtkRenderWindow> renwin = vtkSmartPointer<vtkRenderWindow>::New();    renwin->AddRenderer(ren);    renwin->SetSize(740, 480);    vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New();    iren->SetRenderWindow(renwin);    iren->Initialize();    renwin->Render();    iren->Start();    return 0;}

使用tkVolumeRayCastCompositeFunction类

#include "vtkRenderer.h"  #include "vtkRenderWindow.h"  #include "vtkRenderWindowInteractor.h"  #include "vtkActor.h"  #include "vtkSmartPointer.h"  #include "vtkProperty.h"  #include "vtkCamera.h"  #include "vtkDICOMImageReader.h"  #include "vtkImageCast.h"  #include "vtkPiecewiseFunction.h"  #include "vtkColorTransferFunction.h"  #include "vtkVolumeProperty.h"  #include "vtkVolumeRayCastCompositeFunction.h"  #include "vtkVolumeRayCastMapper.h"  #include "vtkVolume.h" #include "vtkAutoInit.h"VTK_MODULE_INIT(vtkRenderingOpenGL);VTK_MODULE_INIT(vtkInteractionStyle);VTK_MODULE_INIT(vtkRenderingFreeType);VTK_MODULE_INIT(vtkRenderingVolumeOpenGL);int main(){    std::string str = "F:\\CT3";    vtkSmartPointer<vtkDICOMImageReader> reader = vtkSmartPointer<vtkDICOMImageReader>::New();    reader->SetDirectoryName(str.c_str());    reader->SetDataByteOrderToLittleEndian();// 小端字节序    reader->Update();    vtkSmartPointer<vtkImageCast> imageCast = vtkSmartPointer<vtkImageCast>::New();    imageCast->SetInputConnection(reader->GetOutputPort());    imageCast->SetOutputScalarTypeToUnsignedShort();    imageCast->Update();    vtkSmartPointer<vtkPiecewiseFunction> opacityFun = vtkSmartPointer<vtkPiecewiseFunction>::New();    opacityFun->AddPoint(120,0.0);    opacityFun->AddPoint(250,1.0);    opacityFun->AddPoint(520,1.0);    opacityFun->AddPoint(650,0.0);    vtkSmartPointer<vtkColorTransferFunction> TransferFun = vtkSmartPointer<vtkColorTransferFunction>::New();    TransferFun->AddRGBPoint(120, 255 / 255.0, 98 / 255.0, 98 / 255.0);    TransferFun->AddRGBPoint(250, 255 / 255.0, 255 / 255.0, 180 / 255.0);    TransferFun->AddRGBPoint(520, 1.0, 1.0, 1.0);    TransferFun->AddRGBPoint(650, 1.0, 1.0, 1.0);    vtkSmartPointer<vtkPiecewiseFunction> grideFun = vtkSmartPointer<vtkPiecewiseFunction>::New();    grideFun->AddPoint(120, 2.0);    grideFun->AddPoint(250, 2.0);    grideFun->AddPoint(520, 0.1);    grideFun->AddPoint(650, 0.1);    vtkSmartPointer<vtkVolumeProperty> volumeProperty = vtkSmartPointer<vtkVolumeProperty>::New();    volumeProperty->SetColor(TransferFun);    volumeProperty->SetScalarOpacity(opacityFun);    volumeProperty->SetGradientOpacity(grideFun);    volumeProperty->ShadeOn();    volumeProperty->SetAmbient(0.2);    volumeProperty->SetDiffuse(0.9);    volumeProperty->SetSpecular(0.2);    volumeProperty->SetSpecularPower(10);    vtkSmartPointer<vtkVolumeRayCastCompositeFunction> rayCastFun = vtkSmartPointer<vtkVolumeRayCastCompositeFunction>::New();    vtkSmartPointer<vtkVolumeRayCastMapper> mapper1 = vtkSmartPointer<vtkVolumeRayCastMapper>::New();    mapper1->SetVolumeRayCastFunction(rayCastFun);    mapper1->SetInputConnection(imageCast->GetOutputPort());    mapper1->SetAutoAdjustSampleDistances(0);    vtkSmartPointer<vtkVolume> volume = vtkSmartPointer<vtkVolume>::New();    volume->SetMapper(mapper1);    volume->SetProperty(volumeProperty);    vtkSmartPointer<vtkRenderer> ren = vtkSmartPointer<vtkRenderer>::New();    ren->AddVolume(volume);    ren->SetBackground(1.0,1.0,1.0);    vtkSmartPointer<vtkRenderWindow> renwin = vtkSmartPointer<vtkRenderWindow>::New();    renwin->AddRenderer(ren);    renwin->SetSize(740, 480);    vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New();    iren->SetRenderWindow(renwin);    iren->Initialize();    renwin->Render();    iren->Start();    return 0;}

使用vtkPiecewiseFunction 设置不透明度和梯度不透明vtkTransferFunctiony设置颜色传输。