ImageStencil
VTKExamples/Cxx/Images/ImageStencil
Description¶
This example creates a red image and a green image. It creates a mask that is half on and half off. It then combines the images according to the mask using an ImageStencil.
Seealso
Code¶
ImageStencil.cxx
#include <vtkVersion.h> #include <vtkImageData.h> #include <vtkImageMapper3D.h> #include <vtkImageStencil.h> #include <vtkImageStencilData.h> #include <vtkImageToImageStencil.h> #include <vtkJPEGReader.h> #include <vtkPointData.h> #include <vtkSmartPointer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkInteractorStyleImage.h> #include <vtkRenderer.h> #include <vtkImageActor.h> static void CreateColorImage(vtkImageData*, unsigned int channel); static void CreateMask(vtkImageData*); int main(int, char *[]) { vtkSmartPointer<vtkImageData> image1 = vtkSmartPointer<vtkImageData>::New(); CreateColorImage(image1, 0); // Create a red image vtkSmartPointer<vtkImageData> image2 = vtkSmartPointer<vtkImageData>::New(); CreateColorImage(image2, 1); // Create a green image vtkSmartPointer<vtkImageData> mask = vtkSmartPointer<vtkImageData>::New(); CreateMask(mask); //vtkSmartPointer<vtkImageStencilData> stencilData = vtkSmartPointer<vtkImageStencilData>::New(); vtkSmartPointer<vtkImageToImageStencil> imageToImageStencil = vtkSmartPointer<vtkImageToImageStencil>::New(); #if VTK_MAJOR_VERSION <= 5 imageToImageStencil->SetInputConnection(mask->GetProducerPort()); #else imageToImageStencil->SetInputData(mask); #endif imageToImageStencil->ThresholdByUpper(122); vtkSmartPointer<vtkImageStencil> stencil = vtkSmartPointer<vtkImageStencil>::New(); stencil->SetInputConnection(2, imageToImageStencil->GetOutputPort()); stencil->ReverseStencilOn(); #if VTK_MAJOR_VERSION <= 5 stencil->SetBackgroundInput(image2); stencil->SetInputConnection(image1->GetProducerPort()); #else stencil->SetBackgroundInputData(image2); stencil->SetInputData(image1); #endif stencil->Update(); // Create an actor vtkSmartPointer<vtkImageActor> actor = vtkSmartPointer<vtkImageActor>::New(); actor->GetMapper()->SetInputConnection(stencil->GetOutputPort()); // Setup renderer vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); renderer->AddActor(actor); renderer->ResetCamera(); // Setup render window vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->AddRenderer(renderer); // Setup render window interactor vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); vtkSmartPointer<vtkInteractorStyleImage> style = vtkSmartPointer<vtkInteractorStyleImage>::New(); renderWindowInteractor->SetInteractorStyle(style); // Render and start interaction renderWindowInteractor->SetRenderWindow(renderWindow); renderWindowInteractor->Start(); return EXIT_SUCCESS; } void CreateColorImage(vtkImageData* image, const unsigned int channel) { unsigned int dim = 20; image->SetDimensions(dim, dim, 1); #if VTK_MAJOR_VERSION <= 5 image->SetNumberOfScalarComponents(3); image->SetScalarTypeToUnsignedChar(); image->AllocateScalars(); #else image->AllocateScalars(VTK_UNSIGNED_CHAR,3); #endif for(unsigned int x = 0; x < dim; x++) { for(unsigned int y = 0; y < dim; y++) { unsigned char* pixel = static_cast<unsigned char*>(image->GetScalarPointer(x,y,0)); pixel[0] = 0; pixel[1] = 0; pixel[2] = 0; pixel[channel] = 255; } } image->Modified(); } static void CreateMask(vtkImageData* image) { unsigned int dim = 20; image->SetDimensions(dim, dim, 1); #if VTK_MAJOR_VERSION <= 5 image->SetNumberOfScalarComponents(1); image->SetScalarTypeToUnsignedChar(); image->AllocateScalars(); #else image->AllocateScalars(VTK_UNSIGNED_CHAR, 1); #endif for(unsigned int x = 0; x < dim; x++) { for(unsigned int y = 0; y < dim; y++) { unsigned char* pixel = static_cast<unsigned char*>(image->GetScalarPointer(x,y,0)); if(x < dim/2) { pixel[0] = 0; } else { pixel[0] = 255; } } } image->Modified(); }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ImageStencil) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ImageStencil MACOSX_BUNDLE ImageStencil.cxx) target_link_libraries(ImageStencil ${VTK_LIBRARIES})
Download and Build ImageStencil¶
Danger
The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.
Click here to download ImageStencil and its CMakeLists.txt file. Once the tarball ImageStencil.tar has been downloaded and extracted,
cd ImageStencil/build
If VTK is installed:
cmake ..
If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:
cmake -DVTK_DIR:PATH=/home/me/vtk_build ..
Build the project:
make
and run it:
./ImageStencil
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.