VTK 实例37：梯度算子（边缘检测）

 1 #include "vtkAutoInit.h" 
 2 VTK_MODULE_INIT(vtkRenderingOpenGL2);
 3 VTK_MODULE_INIT(vtkInteractionStyle);
 4 
 5 #include <vtkSmartPointer.h>
 6 #include <vtkImageData.h>
 7 #include <vtkRenderWindow.h>
 8 #include <vtkRenderWindowInteractor.h>
 9 #include <vtkInteractorStyleImage.h>
10 #include <vtkRenderer.h>
11 #include <vtkImageActor.h>
12 #include <vtkJPEGReader.h>
13 #include <vtkImageGradient.h>
14 #include <vtkImageMagnitude.h>
15 #include <vtkImageCast.h>
16 #include <vtkImageShiftScale.h>
17 
18 //测试图像：../data/lena-gray.jpg
19 int main(int argc, char* argv[])
20 {
21     vtkSmartPointer<vtkJPEGReader> reader =
22         vtkSmartPointer<vtkJPEGReader>::New();
23     reader->SetFileName("lena-gray.jpg");
24     reader->Update();
25 
26     vtkSmartPointer<vtkImageGradient> gradientFilter =
27         vtkSmartPointer<vtkImageGradient>::New();
28     gradientFilter->SetInputConnection(reader->GetOutputPort());
29     gradientFilter->SetDimensionality(2);
30 
31     vtkSmartPointer<vtkImageMagnitude> magnitudeFilter =
32         vtkSmartPointer<vtkImageMagnitude>::New();
33     magnitudeFilter->SetInputConnection(gradientFilter->GetOutputPort());
34     magnitudeFilter->Update();
35 
36     double range[2];
37     magnitudeFilter->GetOutput()->GetScalarRange(range);
38 
39     vtkSmartPointer<vtkImageShiftScale> ShiftScale =
40         vtkSmartPointer<vtkImageShiftScale>::New();
41     ShiftScale->SetOutputScalarTypeToUnsignedChar();
42     ShiftScale->SetScale( 255 / range[1] );
43     ShiftScale->SetInputConnection(magnitudeFilter->GetOutputPort());
44     ShiftScale->Update();
45 
46     vtkSmartPointer<vtkImageActor> originalActor =
47         vtkSmartPointer<vtkImageActor>::New();
48     originalActor->SetInputData(reader->GetOutput());
49 
50     vtkSmartPointer<vtkImageActor> gradActor =
51         vtkSmartPointer<vtkImageActor>::New();
52     gradActor->SetInputData(ShiftScale->GetOutput());
53 
54     double originalViewport[4] = {0.0, 0.0, 0.5, 1.0};
55     double gradviewport[4] = {0.5, 0.0, 1.0, 1.0};
56 
57     vtkSmartPointer<vtkRenderer> originalRenderer =
58         vtkSmartPointer<vtkRenderer>::New();
59     originalRenderer->SetViewport(originalViewport);
60     originalRenderer->AddActor(originalActor);
61     originalRenderer->ResetCamera();
62     originalRenderer->SetBackground(1.0, 1.0, 1.0);
63 
64     vtkSmartPointer<vtkRenderer> gradRenderer =
65         vtkSmartPointer<vtkRenderer>::New();
66     gradRenderer->SetViewport(gradviewport);
67     gradRenderer->AddActor(gradActor);
68     gradRenderer->ResetCamera();
69     gradRenderer->SetBackground(1.0, 1.0, 1.0);
70 
71     vtkSmartPointer<vtkRenderWindow> renderWindow =
72         vtkSmartPointer<vtkRenderWindow>::New();
73     renderWindow->AddRenderer(originalRenderer);
74     renderWindow->AddRenderer(gradRenderer);
75     renderWindow->SetSize( 640, 320 );
76     renderWindow->Render();
77     renderWindow->SetWindowName("ImageGradientExample");
78 
79     vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
80         vtkSmartPointer<vtkRenderWindowInteractor>::New();
81     vtkSmartPointer<vtkInteractorStyleImage> style =
82         vtkSmartPointer<vtkInteractorStyleImage>::New();
83 
84     renderWindowInteractor->SetInteractorStyle(style);
85     renderWindowInteractor->SetRenderWindow(renderWindow);
86     renderWindowInteractor->Initialize();
87     renderWindowInteractor->Start();
88 
89     return EXIT_SUCCESS;
90 }