VTK 实例40：均值滤波（图像光滑）

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

#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkImageConvolve.h>
#include <vtkImageMandelbrotSource.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkImageCast.h>
#include <vtkJPEGReader.h>
#include <vtkImageShiftScale.h>

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

    vtkSmartPointer<vtkImageCast> originalCastFilter =
        vtkSmartPointer<vtkImageCast>::New();
    originalCastFilter->SetInputConnection(reader->GetOutputPort());
    originalCastFilter->SetOutputScalarTypeToFloat();
    originalCastFilter->Update();

    vtkSmartPointer<vtkImageConvolve> convolveFilter =
        vtkSmartPointer<vtkImageConvolve>::New();
    convolveFilter->SetInputConnection(originalCastFilter->GetOutputPort());

    double kernel[25] = {0.04,0.04,0.04,0.04,0.04,
        0.04,0.04,0.04,0.04,0.04,
        0.04,0.04,0.04,0.04,0.04,
        0.04,0.04,0.04,0.04,0.04,
        0.04,0.04,0.04,0.04,0.04 };
    convolveFilter->SetKernel5x5(kernel);
    convolveFilter->Update();

    vtkSmartPointer<vtkImageCast> convCastFilter = 
        vtkSmartPointer<vtkImageCast>::New();
    convCastFilter->SetInputData(convolveFilter->GetOutput());
    convCastFilter->SetOutputScalarTypeToUnsignedChar();
    convCastFilter->Update();

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

    vtkSmartPointer<vtkImageActor> convolvedActor =
        vtkSmartPointer<vtkImageActor>::New();
    convolvedActor->SetInputData(convCastFilter->GetOutput());

    double leftViewport[4] = {0.0, 0.0, 0.5, 1.0};
    double rightViewport[4] = {0.5, 0.0, 1.0, 1.0};

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

    vtkSmartPointer<vtkRenderer> convolvedRenderer =
        vtkSmartPointer<vtkRenderer>::New();
    convolvedRenderer->SetViewport(rightViewport);
    convolvedRenderer->AddActor(convolvedActor);
    convolvedRenderer->SetBackground(1.0, 1.0, 1.0);
    convolvedRenderer->ResetCamera();

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

    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;
}