VTK 实例36：图像二值化

#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 <vtkJPEGReader.h>
#include <vtkImageThreshold.h>
#include <vtkImageCast.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<vtkImageThreshold> thresholdFilter =
        vtkSmartPointer<vtkImageThreshold>::New();
    thresholdFilter->SetInputConnection(reader->GetOutputPort());
    thresholdFilter->ThresholdByUpper(100);//设置阈值为100
    thresholdFilter->SetInValue(255);//大于100的设置为255
    thresholdFilter->SetOutValue(0);//小于100的设置为0
    thresholdFilter->Update();//算法执行后必须添加更新消息

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

    vtkSmartPointer<vtkImageActor> binaryActor =
        vtkSmartPointer<vtkImageActor>::New();
    binaryActor->SetInputData(thresholdFilter->GetOutput());

    double originalViewport[4] = {0.0, 0.0, 0.5, 1.0};
    double binaryviewport[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> binaryRenderer =
        vtkSmartPointer<vtkRenderer>::New();
    binaryRenderer->SetViewport(binaryviewport);
    binaryRenderer->AddActor(binaryActor);
    binaryRenderer->ResetCamera();
    binaryRenderer->SetBackground(1.0, 1.0, 1.0);

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

    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;
}