VTK系列39_使用拉普拉斯算子实现图像边缘检测

实例39：拉普拉斯算子（边缘检测）

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

#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkImageCanvasSource2D.h>
#include <vtkImageShiftScale.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkJPEGReader.h>
#include <vtkImageLaplacian.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<vtkImageLaplacian> lapFilter =
		vtkSmartPointer<vtkImageLaplacian>::New();
	lapFilter->SetInputConnection(reader->GetOutputPort());
	lapFilter->SetDimensionality(2);

	double range[2];
	lapFilter->GetOutput()->GetScalarRange(range);

	vtkSmartPointer<vtkImageShiftScale> ShiftScale =
		vtkSmartPointer<vtkImageShiftScale>::New();
	ShiftScale->SetOutputScalarTypeToUnsignedChar();
	ShiftScale->SetScale( 255 / (range[1]-range[0]) );
	ShiftScale->SetShift(-range[0]);
	ShiftScale->SetInputConnection(lapFilter->GetOutputPort());
	ShiftScale->Update();

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

	vtkSmartPointer<vtkImageActor> gradActor =
		vtkSmartPointer<vtkImageActor>::New();
	gradActor->SetInputData(ShiftScale->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(gradActor);
	gradRenderer->ResetCamera();
	gradRenderer->SetBackground(1.0, 1.0, 1.0);

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

	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;
}

VTK系列目录：

1 VTK基本概念

2 VTK图像处理

3 VTK图形处理

4 VTK体绘制