VTK之图像处理

在VTK中，图像数据被作为一种特别的数据类型来处理，由vtkImageData表示，这种数据类型是结构化的，这意味着每个数据点的位置可隐含由图像数据的原点（第一张图像左下角在世界坐标系中的位置）、数据点间距（沿坐标方向相邻两个数据点的距离，或体素的长宽高）和维数（沿坐标方向体素或数据点的数目）确定。

 

VTK为图像数据提供了很多处理类，这里给出运行成功的代码示例（pReader读取图像文件）：

 

（1）计算梯度：

 

 vtkImageGradient* pGradient = vtkImageGradient::New();

 pGradient->SetInput((vtkDataObject*)pReader->GetOutput());

 pGradient->SetDimensionality(3);

 

 vtkImageViewer* pViewer = vtkImageViewer::New();

 pViewer->SetInput(pGradient->GetOutput());

 pViewer->SetColorLevel(127.5);

 pViewer->SetColorWindow(256);

 pViewer->GetActor2D()->SetPosition(0,0);

 

 vtkRenderWindow* pRenWnd = vtkRenderWindow::New();

 pRenWnd->AddRenderer(pViewer->GetRenderer());

 pRenWnd->SetSize(512, 512);

 

 vtkRenderWindowInteractor* pRenWndInact = vtkRenderWindowInteractor::New();

 pRenWndInact->SetRenderWindow(pRenWnd);

 pRenWndInact->Initialize();

 pRenWndInact->Start();

 

（2）高斯平滑：

 

 vtkImageGaussianSmooth* pGaussian = vtkImageGaussianSmooth::New();

 pGaussian->SetInput((vtkDataObject*)pReader->GetOutput());

 pGaussian->SetDimensionality(2);

 pGaussian->SetStandardDeviations(1, 1);

 

 vtkImageViewer* pViewer = vtkImageViewer::New();

 pViewer->SetInput(pGaussian->GetOutput());

 pViewer->SetColorLevel(127.5);

 pViewer->SetColorWindow(256);

 pViewer->GetActor2D()->SetPosition(0,0);

 

 vtkRenderWindow* pRenWnd = vtkRenderWindow::New();

 pRenWnd->AddRenderer(pViewer->GetRenderer());

 pRenWnd->SetSize(512, 512);

 

 vtkRenderWindowInteractor* pRenWndInact = vtkRenderWindowInteractor::New();

 pRenWndInact->SetRenderWindow(pRenWnd);

 pRenWndInact->Initialize();

 pRenWndInact->Start();

 

（3）直方图：

 

 double range[2];

 vtkImageData* pImg = (vtkImageData*)pReader->GetOutput();

 pImg->Update();

 pImg->GetScalarRange(range);

 

 vtkImageAccumulate* pHistgram = vtkImageAccumulate::New();

 pHistgram->SetInput((vtkDataObject*)pReader->GetOutput());

 pHistgram->SetComponentExtent(0, static_cast<int>(range[1] - range[0]), 0, 0, 0, 0);

 pHistgram->SetComponentOrigin(range[0], 0, 0);

 pHistgram->UpdateWholeExtent();

 

 vtkXYPlotActor* plot = vtkXYPlotActor::New();

 plot->ExchangeAxesOff();

 plot->SetLabelFormat("%g");

 plot->SetXRange(range[0], range[1]);

 plot->SetYRange(0, 4096);

 plot->SetXTitle("Gray Level");

 plot->SetYTitle("");

 plot->AddInput(pHistgram->GetOutput());

 plot->SetXValuesToValue();

 

 vtkRenderer* pRender = vtkRenderer::New();

 pRender->AddActor(plot);

 

 vtkRenderWindow* pRenWnd = vtkRenderWindow::New();

 pRenWnd->AddRenderer(pRender);

 pRenWnd->SetSize(512, 512);

 

 vtkRenderWindowInteractor* pRenWndInact = vtkRenderWindowInteractor::New();

 pRenWndInact->SetRenderWindow(pRenWnd);

 pRenWndInact->Initialize();

 pRenWndInact->Start();

（4）布尔逻辑计算：

 vtkImageEllipsoidSource* psrc1 = vtkImageEllipsoidSource::New();

 vtkImageEllipsoidSource* psrc2 = vtkImageEllipsoidSource::New();

 psrc1->SetCenter(100, 100, 0);

 psrc2->SetCenter(170, 100, 0);

 psrc1->SetRadius(70, 70, 70);

 psrc2->SetRadius(70, 70, 70);

 

 vtkImageLogic* pxor = vtkImageLogic::New();

 pxor->SetInput1((vtkDataObject *)psrc1->GetOutput());

 pxor->SetInput2((vtkDataObject *)psrc2->GetOutput());

 pxor->SetOperationToXor();

 pxor->SetOutputTrueValue(150);

 vtkImageViewer* pViewer = vtkImageViewer::New();

 pViewer->SetInput(pxor->GetOutput());

 pViewer->SetColorWindow(255);

 pViewer->SetColorLevel(127.5);

 vtkRenderWindow* pRenWnd = vtkRenderWindow::New();

 pRenWnd->AddRenderer(pViewer->GetRenderer());

 pRenWnd->SetSize(270, 200);

 vtkRenderWindowInteractor* pRenWndInact = vtkRenderWindowInteractor::New();

 pRenWndInact->SetRenderWindow(pRenWnd);

 pRenWndInact->Initialize();

 pRenWndInact->Start();

 

trackback:http://blog.csdn.net/bingo_gmwu/article/details/4747038