ExtractComponents
VTKExamples/Cxx/Images/ExtractComponents
Description
This example separates an image into the red channel, the green channel, and the blue channel using {{class|vtkImageExtractComponents}}.
For the reverse operation, see .
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
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.