ImageCorrelation
VTKExamples/Cxx/Images/ImageCorrelation
Code¶
ImageCorrelation.cxx
#include <vtkSmartPointer.h> #include <vtkImageShiftScale.h> #include <vtkImageCast.h> #include <vtkImageMapper3D.h> #include <vtkMath.h> #include <vtkImageData.h> #include <vtkPointData.h> #include <vtkDataArray.h> #include <vtkImageCanvasSource2D.h> #include <vtkImageCorrelation.h> #include <vtkInteractorStyleImage.h> #include <vtkImageActor.h> #include <vtkActor.h> #include <vtkRenderWindow.h> #include <vtkRenderer.h> #include <vtkRenderWindowInteractor.h> int main(int, char *[]) { // Create an image vtkSmartPointer<vtkImageCanvasSource2D> imageSource = vtkSmartPointer<vtkImageCanvasSource2D>::New(); imageSource->SetNumberOfScalarComponents(3); imageSource->SetScalarTypeToUnsignedChar(); imageSource->SetExtent(0, 300, 0, 300, 0, 0); imageSource->SetDrawColor(0, 0, 0); imageSource->FillBox(0, 300, 0, 300); imageSource->SetDrawColor(255, 0, 0); //red imageSource->FillTriangle(10, 100, 190, 150, 40, 250); imageSource->Update(); // Create an actor vtkSmartPointer<vtkImageActor> originalActor = vtkSmartPointer<vtkImageActor>::New(); originalActor->GetMapper()->SetInputConnection( imageSource->GetOutputPort()); // Create a kernel vtkSmartPointer<vtkImageCanvasSource2D> kernelSource = vtkSmartPointer<vtkImageCanvasSource2D>::New(); kernelSource->SetNumberOfScalarComponents(3); kernelSource->SetScalarTypeToUnsignedChar(); kernelSource->SetExtent(0, 30, 0, 30, 0, 0); kernelSource->SetDrawColor(0, 0, 0); kernelSource->FillBox(0, 30, 0, 30); kernelSource->SetDrawColor(255, 0, 0); //red kernelSource->FillTriangle(10, 1, 25, 10, 1, 5); kernelSource->Update(); // Create an actor vtkSmartPointer<vtkImageActor> kernelActor = vtkSmartPointer<vtkImageActor>::New(); kernelActor->GetMapper()->SetInputConnection( kernelSource->GetOutputPort()); // Compute the correlation vtkSmartPointer<vtkImageCorrelation> correlationFilter = vtkSmartPointer<vtkImageCorrelation>::New(); correlationFilter->SetInputConnection(0, imageSource->GetOutputPort()); correlationFilter->SetInputConnection(1, kernelSource->GetOutputPort()); correlationFilter->Update(); // At this point, corr pixels are doubles // So, get the scalar range vtkImageData* corr = correlationFilter->GetOutput(); double corrRange[2]; corr->GetPointData()->GetScalars()->GetRange( corrRange ); // Rescale the correlation filter output. note that it implies // that minimum correlation is always zero. vtkSmartPointer<vtkImageShiftScale> imageScale = vtkSmartPointer<vtkImageShiftScale>::New(); imageScale->SetInputConnection( correlationFilter->GetOutputPort( )); imageScale->SetScale( 255 / corrRange[1] ); imageScale->SetOutputScalarTypeToUnsignedChar( ); imageScale->Update(); vtkSmartPointer<vtkImageCast> correlationCastFilter = vtkSmartPointer<vtkImageCast>::New(); correlationCastFilter->SetInputConnection(imageScale->GetOutputPort()); correlationCastFilter->SetOutputScalarTypeToUnsignedChar(); correlationCastFilter->Update(); // Create an actor vtkSmartPointer<vtkImageActor> correlationActor = vtkSmartPointer<vtkImageActor>::New(); correlationActor->GetMapper()->SetInputConnection( correlationCastFilter->GetOutputPort()); // Define viewport ranges // (xmin, ymin, xmax, ymax) double originalViewport[4] = {0.0, 0.0, 0.33, 1.0}; double kernelViewport[4] = {0.33, 0.0, 0.66, 1.0}; double correlationViewport[4] = {0.66, 0.0, 1.0, 1.0}; // Setup renderers vtkSmartPointer<vtkRenderer> originalRenderer = vtkSmartPointer<vtkRenderer>::New(); originalRenderer->SetViewport(originalViewport); originalRenderer->AddActor(originalActor); originalRenderer->ResetCamera(); vtkSmartPointer<vtkRenderer> kernelRenderer = vtkSmartPointer<vtkRenderer>::New(); kernelRenderer->SetViewport(kernelViewport); kernelRenderer->AddActor(kernelActor); kernelRenderer->ResetCamera(); vtkSmartPointer<vtkRenderer> correlationRenderer = vtkSmartPointer<vtkRenderer>::New(); correlationRenderer->SetViewport(correlationViewport); correlationRenderer->AddActor(correlationActor); correlationRenderer->ResetCamera(); // Setup render window vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->SetSize(900,300); renderWindow->AddRenderer(originalRenderer); renderWindow->AddRenderer(kernelRenderer); renderWindow->AddRenderer(correlationRenderer); // 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(ImageCorrelation) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ImageCorrelation MACOSX_BUNDLE ImageCorrelation.cxx) target_link_libraries(ImageCorrelation ${VTK_LIBRARIES})
Download and Build ImageCorrelation¶
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 ImageCorrelation and its CMakeLists.txt file. Once the tarball ImageCorrelation.tar has been downloaded and extracted,
cd ImageCorrelation/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:
./ImageCorrelation
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.