VTK学习笔记之图像处理

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();

本文来源：http://blog.csdn.net/bingo_gmwu/article/details/4747038