ExtractComponents
VTKExamples/Cxx/Images/ExtractComponents
Description¶
This example separates an image into the red channel, the green channel, and the blue channel using vtkImageExtractComponents.
Seealso
For the reverse operation, see CombiningRGBChannelss.
Code¶
ExtractComponents.cxx
#include <vtkImageData.h> #include <vtkJPEGReader.h> #include <vtkSmartPointer.h> #include <vtkImageExtractComponents.h> #include <vtkImageMapper3D.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkInteractorStyleImage.h> #include <vtkRenderer.h> #include <vtkJPEGReader.h> #include <vtkImageActor.h> int main(int argc, char *argv[]) { // Verify command line arguments if (argc != 2 ) { std::cout << "Required parameters: InputFilename" << std::endl; return EXIT_FAILURE; } // Parse command line arguments std::string inputFilename = argv[1]; // Read JPG file vtkSmartPointer<vtkJPEGReader> reader = vtkSmartPointer<vtkJPEGReader>::New(); reader->SetFileName(inputFilename.c_str()); reader->Update(); vtkSmartPointer<vtkImageExtractComponents> extractRedFilter = vtkSmartPointer<vtkImageExtractComponents>::New(); extractRedFilter->SetInputConnection(reader->GetOutputPort()); extractRedFilter->SetComponents(0); extractRedFilter->Update(); vtkSmartPointer<vtkImageExtractComponents> extractGreenFilter = vtkSmartPointer<vtkImageExtractComponents>::New(); extractGreenFilter->SetInputConnection(reader->GetOutputPort()); extractGreenFilter->SetComponents(1); extractGreenFilter->Update(); vtkSmartPointer<vtkImageExtractComponents> extractBlueFilter = vtkSmartPointer<vtkImageExtractComponents>::New(); extractBlueFilter->SetInputConnection(reader->GetOutputPort()); extractBlueFilter->SetComponents(2); extractBlueFilter->Update(); // Create actors vtkSmartPointer<vtkImageActor> inputActor = vtkSmartPointer<vtkImageActor>::New(); inputActor->GetMapper()->SetInputConnection(reader->GetOutputPort()); vtkSmartPointer<vtkImageActor> redActor = vtkSmartPointer<vtkImageActor>::New(); redActor->GetMapper()->SetInputConnection(extractRedFilter->GetOutputPort()); vtkSmartPointer<vtkImageActor> greenActor = vtkSmartPointer<vtkImageActor>::New(); greenActor->GetMapper()->SetInputConnection(extractGreenFilter->GetOutputPort()); vtkSmartPointer<vtkImageActor> blueActor = vtkSmartPointer<vtkImageActor>::New(); blueActor->GetMapper()->SetInputConnection(extractBlueFilter->GetOutputPort()); // Define viewport ranges // (xmin, ymin, xmax, ymax) double inputViewport[4] = {0.0, 0.0, 0.25, 1.0}; double redViewport[4] = {0.25, 0.0, 0.5, 1.0}; double greenViewport[4] = {0.5, 0.0, 0.75, 1.0}; double blueViewport[4] = {0.75, 0.0, 1.0, 1.0}; // Setup renderers vtkSmartPointer<vtkRenderer> inputRenderer = vtkSmartPointer<vtkRenderer>::New(); inputRenderer->SetViewport(inputViewport); inputRenderer->AddActor(inputActor); inputRenderer->ResetCamera(); inputRenderer->SetBackground(.4, .5, .9); vtkSmartPointer<vtkRenderer> redRenderer = vtkSmartPointer<vtkRenderer>::New(); redRenderer->SetViewport(redViewport); redRenderer->AddActor(redActor); redRenderer->ResetCamera(); redRenderer->SetBackground(.4, .5, .6); vtkSmartPointer<vtkRenderer> greenRenderer = vtkSmartPointer<vtkRenderer>::New(); greenRenderer->SetViewport(greenViewport); greenRenderer->AddActor(greenActor); greenRenderer->ResetCamera(); greenRenderer->SetBackground(.4, .5, .7); vtkSmartPointer<vtkRenderer> blueRenderer = vtkSmartPointer<vtkRenderer>::New(); blueRenderer->SetViewport(blueViewport); blueRenderer->AddActor(blueActor); blueRenderer->ResetCamera(); blueRenderer->SetBackground(.4, .5, .8); // Setup render window vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->SetSize(1000, 250); renderWindow->AddRenderer(inputRenderer); renderWindow->AddRenderer(redRenderer); renderWindow->AddRenderer(greenRenderer); renderWindow->AddRenderer(blueRenderer); // 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->Initialize(); renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ExtractComponents) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ExtractComponents MACOSX_BUNDLE ExtractComponents.cxx) target_link_libraries(ExtractComponents ${VTK_LIBRARIES})
Download and Build ExtractComponents¶
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 ExtractComponents and its CMakeLists.txt file. Once the tarball ExtractComponents.tar has been downloaded and extracted,
cd ExtractComponents/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:
./ExtractComponents
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.