ImageMask
VTKExamples/Cxx/Images/ImageMask
Description¶
This example creates an all red image. Then it creates a mask of a small rectangle. The red pixels in this rectangle are copied to the output image, while the rest of the output image is black. The black region could be set to a different color using SetMaskedOutputValue.
Code¶
ImageMask.cxx
#include <vtkSmartPointer.h> #include <vtkImageData.h> #include <vtkImageMapper3D.h> #include <vtkJPEGWriter.h> #include <vtkImageCanvasSource2D.h> #include <vtkImageMask.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkInteractorStyleImage.h> #include <vtkRenderer.h> #include <vtkJPEGReader.h> #include <vtkImageActor.h> #include <vtkImageEllipsoidSource.h> #include <vtkImageCast.h> int main(int, char *[]) { // Create an image of a rectangle vtkSmartPointer<vtkImageCanvasSource2D> source = vtkSmartPointer<vtkImageCanvasSource2D>::New(); source->SetScalarTypeToUnsignedChar(); source->SetNumberOfScalarComponents(3); source->SetExtent(0, 200, 0, 200, 0, 0); // Create a red image source->SetDrawColor(255,0,0); source->FillBox(0,200,0,200); source->Update(); // Create a rectanglular mask vtkSmartPointer<vtkImageCanvasSource2D> maskSource = vtkSmartPointer<vtkImageCanvasSource2D>::New(); maskSource->SetScalarTypeToUnsignedChar(); maskSource->SetNumberOfScalarComponents(1); maskSource->SetExtent(0, 200, 0, 200, 0, 0); // Initialize the mask to black maskSource->SetDrawColor(0,0,0); maskSource->FillBox(0,200,0,200); // Create a square maskSource->SetDrawColor(255,255,255); //anything non-zero means "make the output pixel equal the input pixel." If the mask is zero, the output pixel is set to MaskedValue maskSource->FillBox(100,120,100,120); maskSource->Update(); vtkSmartPointer<vtkImageMask> maskFilter = vtkSmartPointer<vtkImageMask>::New(); maskFilter->SetInputConnection(0, source->GetOutputPort()); maskFilter->SetInputConnection(1, maskSource->GetOutputPort()); maskFilter->SetMaskedOutputValue(0,1,0); maskFilter->Update(); vtkSmartPointer<vtkImageMask> inverseMaskFilter = vtkSmartPointer<vtkImageMask>::New(); inverseMaskFilter->SetInputConnection(0, source->GetOutputPort()); inverseMaskFilter->SetInputConnection(1, maskSource->GetOutputPort()); inverseMaskFilter->SetMaskedOutputValue(0,1,0); inverseMaskFilter->NotMaskOn(); inverseMaskFilter->Update(); // Create actors vtkSmartPointer<vtkImageActor> originalActor = vtkSmartPointer<vtkImageActor>::New(); originalActor->GetMapper()->SetInputConnection(source->GetOutputPort()); vtkSmartPointer<vtkImageActor> maskActor = vtkSmartPointer<vtkImageActor>::New(); maskActor->GetMapper()->SetInputConnection(maskSource->GetOutputPort()); vtkSmartPointer<vtkImageActor> maskedActor = vtkSmartPointer<vtkImageActor>::New(); maskedActor->GetMapper()->SetInputConnection(maskFilter->GetOutputPort()); vtkSmartPointer<vtkImageActor> inverseMaskedActor = vtkSmartPointer<vtkImageActor>::New(); inverseMaskedActor->GetMapper()->SetInputConnection(inverseMaskFilter->GetOutputPort()); // Define viewport ranges // (xmin, ymin, xmax, ymax) double originalViewport[4] = {0.0, 0.0, 0.25, 1.0}; double maskViewport[4] = {0.25, 0.0, 0.5, 1.0}; double maskedViewport[4] = {0.5, 0.0, 0.75, 1.0}; double inverseMaskedViewport[4] = {0.75, 0.0, 1.0, 1.0}; // Setup renderers vtkSmartPointer<vtkRenderer> originalRenderer = vtkSmartPointer<vtkRenderer>::New(); originalRenderer->SetViewport(originalViewport); originalRenderer->AddActor(originalActor); originalRenderer->ResetCamera(); originalRenderer->SetBackground(.4, .5, .6); vtkSmartPointer<vtkRenderer> maskRenderer = vtkSmartPointer<vtkRenderer>::New(); maskRenderer->SetViewport(maskViewport); maskRenderer->AddActor(maskActor); maskRenderer->ResetCamera(); maskRenderer->SetBackground(.4, .5, .6); vtkSmartPointer<vtkRenderer> maskedRenderer = vtkSmartPointer<vtkRenderer>::New(); maskedRenderer->SetViewport(maskedViewport); maskedRenderer->AddActor(maskedActor); maskedRenderer->ResetCamera(); maskedRenderer->SetBackground(.4, .5, .6); vtkSmartPointer<vtkRenderer> inverseMaskedRenderer = vtkSmartPointer<vtkRenderer>::New(); inverseMaskedRenderer->SetViewport(inverseMaskedViewport); inverseMaskedRenderer->AddActor(inverseMaskedActor); inverseMaskedRenderer->ResetCamera(); inverseMaskedRenderer->SetBackground(.4, .5, .7); vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->SetSize(1000, 250); renderWindow->AddRenderer(originalRenderer); renderWindow->AddRenderer(maskRenderer); renderWindow->AddRenderer(maskedRenderer); renderWindow->AddRenderer(inverseMaskedRenderer); vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); vtkSmartPointer<vtkInteractorStyleImage> style = vtkSmartPointer<vtkInteractorStyleImage>::New(); renderWindowInteractor->SetInteractorStyle(style); renderWindowInteractor->SetRenderWindow(renderWindow); renderWindowInteractor->Initialize(); renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ImageMask) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ImageMask MACOSX_BUNDLE ImageMask.cxx) target_link_libraries(ImageMask ${VTK_LIBRARIES})
Download and Build ImageMask¶
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 ImageMask and its CMakeLists.txt file. Once the tarball ImageMask.tar has been downloaded and extracted,
cd ImageMask/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:
./ImageMask
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.