在VTK用canny算子进行边缘检测，出不来结果

[qq_41810300]

代码是网上的
#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkImageShiftScale.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkJPEGReader.h>
#include <vtkImageCast.h>
#include <vtkImageGaussianSmooth.h>
#include <vtkImageGradient.h>
#include <vtkImageMagnitude.h>
#include <vtkImageNonMaximumSuppression.h>
#include <vtkImageConstantPad.h>
#include <vtkImageToStructuredPoints.h>
#include <vtkLinkEdgels.h>
#include <vtkThreshold.h>
#include <vtkGeometryFilter.h>
#include <vtkSubPixelPositionEdgels.h>
#include <vtkCamera.h>
#include <vtkProperty.h>
#include <vtkStripper.h>
#include <vtkPolyDataMapper.h>

int main(int argc, char* argv[])
{
vtkSmartPointer<vtkJPEGReader> reader =
vtkSmartPointer<vtkJPEGReader>::New();
reader->SetFileName("D:/360/VTKdaima/Examples/Chap05/data/lena-gray.jpg");
reader->Update();

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

vtkSmartPointer<vtkImageGaussianSmooth> gs =
vtkSmartPointer<vtkImageGaussianSmooth>::New();
gs->SetInputConnection(ic->GetOutputPort());
gs->SetDimensionality(2);
gs->SetRadiusFactors(1, 1, 0);

vtkSmartPointer<vtkImageGradient> imgGradient =
vtkSmartPointer<vtkImageGradient>::New();
imgGradient->SetInputConnection(gs->GetOutputPort());
imgGradient->SetDimensionality(2);

vtkSmartPointer<vtkImageMagnitude> imgMagnitude =
vtkSmartPointer<vtkImageMagnitude>::New();
imgMagnitude->SetInputConnection(imgGradient->GetOutputPort());

vtkSmartPointer<vtkImageNonMaximumSuppression> nonMax =
vtkSmartPointer<vtkImageNonMaximumSuppression>::New();
nonMax->SetMagnitudeInputData(imgMagnitude->GetOutput());
nonMax->SetVectorInputData(imgGradient->GetOutput());
nonMax->SetDimensionality(2);

vtkSmartPointer<vtkImageConstantPad> pad =
vtkSmartPointer<vtkImageConstantPad>::New();
pad->SetInputConnection(imgGradient->GetOutputPort());
pad->SetOutputNumberOfScalarComponents(3);
pad->SetConstant(0);

vtkSmartPointer<vtkImageToStructuredPoints> i2sp1 =
vtkSmartPointer<vtkImageToStructuredPoints>::New();
i2sp1->SetInputConnection(nonMax->GetOutputPort());
i2sp1->SetVectorInputData(pad->GetOutput());

vtkSmartPointer<vtkLinkEdgels> imgLink =
vtkSmartPointer<vtkLinkEdgels>::New();
imgLink->SetInputData(i2sp1->GetOutput());
imgLink->SetGradientThreshold(2);

vtkSmartPointer<vtkThreshold> thresholdEdgels =
vtkSmartPointer<vtkThreshold>::New();
thresholdEdgels->SetInputConnection(imgLink->GetOutputPort());
thresholdEdgels->ThresholdByUpper(10);
thresholdEdgels->AllScalarsOff();

vtkSmartPointer<vtkGeometryFilter> gf =
vtkSmartPointer<vtkGeometryFilter>::New();
gf->SetInputConnection(thresholdEdgels->GetOutputPort());

vtkSmartPointer<vtkImageToStructuredPoints> i2sp =
vtkSmartPointer<vtkImageToStructuredPoints>::New();
i2sp->SetInputConnection(imgMagnitude->GetOutputPort());
i2sp->SetVectorInputData(pad->GetOutput());

vtkSmartPointer<vtkSubPixelPositionEdgels> spe =
vtkSmartPointer<vtkSubPixelPositionEdgels>::New();
spe->SetInputConnection(gf->GetOutputPort());
spe->SetGradMapsData(i2sp->GetStructuredPointsOutput());

vtkSmartPointer<vtkStripper> strip =
vtkSmartPointer<vtkStripper>::New();
strip->SetInputConnection(spe->GetOutputPort());

vtkSmartPointer<vtkPolyDataMapper> dsm =
vtkSmartPointer<vtkPolyDataMapper>::New();
dsm->SetInputConnection(strip->GetOutputPort());
dsm->ScalarVisibilityOff();

vtkSmartPointer<vtkActor> planeActor =
vtkSmartPointer<vtkActor>::New();
planeActor->SetMapper(dsm);
planeActor->GetProperty()->SetAmbient(1.0);
planeActor->GetProperty()->SetDiffuse(0.0);
planeActor->GetProperty()->SetColor(1.0, 0.0, 0.0);

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

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

vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->SetSize(900, 300);
renderWindow->AddRenderer(originalRenderer);
renderWindow->AddRenderer(gradRenderer);
renderWindow->Render();
renderWindow->SetWindowName("CannyExample");

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;
}