VTK 实例26：将BMP类型的RGB图像转换为灰度图像

#include "vtkAutoInit.h" 
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);

#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkBMPReader.h>
#include <vtkImageLuminance.h>

//测试图像：../data/lena.bmp
int main(int argc, char* argv[])
{
    vtkSmartPointer<vtkBMPReader> reader =
    vtkSmartPointer<vtkBMPReader>::New();
    reader->SetFileName ( "lena.bmp" );

    vtkSmartPointer<vtkImageLuminance> luminanceFilter = 
        vtkSmartPointer<vtkImageLuminance>::New();
    luminanceFilter->SetInputConnection(reader->GetOutputPort());
    luminanceFilter->Update();

    vtkSmartPointer<vtkImageActor> originalActor =
        vtkSmartPointer<vtkImageActor>::New();
    originalActor->SetInputData(reader->GetOutput());

    vtkSmartPointer<vtkImageActor> shiftscaleActor =
        vtkSmartPointer<vtkImageActor>::New();
    shiftscaleActor->SetInputData(luminanceFilter->GetOutput());

    double originalViewport[4] = {0.0, 0.0, 0.5, 1.0};
    double shiftscaleViewport[4] = {0.5, 0.0, 1.0, 1.0};

    vtkSmartPointer<vtkRenderer> originalRenderer =
        vtkSmartPointer<vtkRenderer>::New();
    originalRenderer->SetViewport(originalViewport);
    originalRenderer->AddActor(originalActor);
    originalRenderer->ResetCamera();
    originalRenderer->SetBackground(1.0, 1.0, 1.0);

    vtkSmartPointer<vtkRenderer> shiftscaleRenderer =
        vtkSmartPointer<vtkRenderer>::New();
    shiftscaleRenderer->SetViewport(shiftscaleViewport);
    shiftscaleRenderer->AddActor(shiftscaleActor);
    shiftscaleRenderer->ResetCamera();
    shiftscaleRenderer->SetBackground(1.0, 1.0, 1.0);

    vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
    renderWindow->AddRenderer(originalRenderer);
    renderWindow->AddRenderer(shiftscaleRenderer);
    renderWindow->SetSize( 640, 320 );
    renderWindow->Render();
    renderWindow->SetWindowName("Color2GrayImageExample");

    vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
    vtkSmartPointer<vtkInteractorStyleImage> style =
        vtkSmartPointer<vtkInteractorStyleImage>::New();

    renderWindowInteractor->SetInteractorStyle(style);
    renderWindowInteractor->SetRenderWindow(renderWindow);
    renderWindowInteractor->Initialize();

    renderWindowInteractor->Start();

    return EXIT_SUCCESS;
}