VTK中利用vtkImageExtractComponents可以方便的提取出彩色图像的各个颜色分量，该类的使用比较简单，只需要设置要提取的分量序号即可。下面代码说明了怎样提取彩色图像的某个颜色分量。

#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL);#include <vtkSmartPointer.h>
#include <vtkBMPReader.h>
#include <vtkImageExtractComponents.h>
#include <vtkImageActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>int main()
{vtkSmartPointer<vtkBMPReader> reader =vtkSmartPointer<vtkBMPReader>::New();reader->SetFileName("lena.bmp");vtkSmartPointer<vtkImageExtractComponents> redComponent =vtkSmartPointer<vtkImageExtractComponents>::New();redComponent->SetInputConnection(reader->GetOutputPort());redComponent->SetComponents(0);redComponent->Update();vtkSmartPointer<vtkImageExtractComponents> greenComponent =vtkSmartPointer<vtkImageExtractComponents>::New();greenComponent->SetInputConnection(reader->GetOutputPort());greenComponent->SetComponents(1);greenComponent->Update();vtkSmartPointer<vtkImageExtractComponents> blueComponent =vtkSmartPointer<vtkImageExtractComponents>::New();blueComponent->SetInputConnection(reader->GetOutputPort());blueComponent->SetComponents(2);blueComponent->Update();//创建演员vtkSmartPointer<vtkImageActor> origActor =vtkSmartPointer<vtkImageActor>::New();origActor->SetInputData(reader->GetOutput());vtkSmartPointer<vtkImageActor> redActor =vtkSmartPointer<vtkImageActor>::New();redActor->SetInputData(redComponent->GetOutput());vtkSmartPointer<vtkImageActor> greenActor =vtkSmartPointer<vtkImageActor>::New();greenActor->SetInputData(greenComponent->GetOutput());vtkSmartPointer<vtkImageActor> blueActor =vtkSmartPointer<vtkImageActor>::New();blueActor->SetInputData(blueComponent->GetOutput());//定义窗口 并化妆double origView[4] = { 0.0, 0.0, 0.25, 1.0 };double redView[4] = { 0.25, 0.0, 0.5, 1.0 };double greenView[4] = { 0.5, 0.0, 0.75, 1.0 };double blueView[4] = { 0.75, 0.0, 1.0, 1.0 };vtkSmartPointer<vtkRenderer> origRender =vtkSmartPointer<vtkRenderer>::New();origRender->SetViewport(origView);origRender->AddActor(origActor);origRender->ResetCamera();origRender->SetBackground(1.0, 1.0, 1.0);vtkSmartPointer<vtkRenderer> redRender =vtkSmartPointer<vtkRenderer>::New();redRender->SetViewport(redView);redRender->AddActor(redActor);redRender->ResetCamera();redRender->SetBackground(1.0, 1.0, 1.0);vtkSmartPointer<vtkRenderer> greenRender =vtkSmartPointer<vtkRenderer>::New();greenRender->SetViewport(greenView);greenRender->AddActor(greenActor);greenRender->ResetCamera();greenRender->SetBackground(1.0, 1.0, 1.0);vtkSmartPointer<vtkRenderer> blueRender =vtkSmartPointer<vtkRenderer>::New();blueRender->SetViewport(blueView);blueRender->AddActor(blueActor);blueRender->ResetCamera();blueRender->SetBackground(1.0, 1.0, 1.0);//上舞台vtkSmartPointer<vtkRenderWindow> renderwindow =vtkSmartPointer<vtkRenderWindow>::New();renderwindow->AddRenderer(origRender);renderwindow->AddRenderer(redRender);renderwindow->AddRenderer(greenRender);renderwindow->AddRenderer(blueRender);renderwindow->SetSize(960, 320);renderwindow->Render();renderwindow->SetWindowName("ExtraImageColorComponents");//设置交互vtkSmartPointer<vtkRenderWindowInteractor> rwi =vtkSmartPointer<vtkRenderWindowInteractor>::New();vtkSmartPointer<vtkInteractorStyleImage> style =vtkSmartPointer<vtkInteractorStyleImage>::New();rwi->SetInteractorStyle(style);rwi->SetRenderWindow(renderwindow);rwi->Initialize();rwi->Start(); return 0;
}

2.参看资料