ImageTranslateExtent
VTKExamples/Cxx/ImageData/ImageTranslateExtent
Description¶
If you are looking to change the extent to change the "origin" of the image from the corner to the center, see vtkImageChangeInformation (http://www.vtk.org/Wiki/VTK/Examples/Cxx/Images/CenterAnImage).
Currently this method changes the extent (shown by the terminal output in the example), but does not change where the corner of the image is displayed relative to the sphere at (0,0,0).
Code¶
ImageTranslateExtent.cxx
#include <vtkVersion.h> #include <vtkImageData.h> #include <vtkSmartPointer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkInteractorStyleImage.h> #include <vtkRenderer.h> #include <vtkImageMapper.h> #include <vtkImageSliceMapper.h> #include <vtkImageSlice.h> #include <vtkSphereSource.h> #include <vtkPolyDataMapper.h> #include <vtkActor.h> #include <vtkImageTranslateExtent.h> static void CreateColorImage(vtkImageData* const); int main(int, char *[]) { vtkSmartPointer<vtkImageData> colorImage = vtkSmartPointer<vtkImageData>::New(); CreateColorImage(colorImage); // This image has (0,0) at the bottom left corner int extent[6]; colorImage->GetExtent(extent); std::cout << "Old extent: " << extent[0] << " " << extent[1] << " " << extent[2] << " " << extent[3] << " " << extent[4] << " " << extent[5] << std::endl; // This moves the (0,0) position in the image to the center of the image // int extent[6]; // colorImage->GetExtent(extent); // colorImage->SetExtent(extent[0] - (extent[1] - extent[0])/2, extent[0] + (extent[1] - extent[0])/2, // extent[2] - (extent[3] - extent[2])/2, extent[2] + (extent[3] - extent[2])/2, // extent[4] - (extent[5] - extent[4])/2, extent[4] + (extent[5] - extent[4])/2); int dimensions[3]; colorImage->GetDimensions(dimensions); vtkSmartPointer<vtkImageTranslateExtent> translateExtent = vtkSmartPointer<vtkImageTranslateExtent>::New(); translateExtent->SetTranslation(-dimensions[0]/2,-dimensions[1]/2,0); #if VTK_MAJOR_VERSION <= 5 translateExtent->SetInput(colorImage); #else translateExtent->SetInputData(colorImage); #endif translateExtent->Update(); colorImage->DeepCopy(translateExtent->GetOutput()); colorImage->GetExtent(extent); std::cout << "New extent: " << extent[0] << " " << extent[1] << " " << extent[2] << " " << extent[3] << " " << extent[4] << " " << extent[5] << std::endl; vtkSmartPointer<vtkSphereSource> sphereSource = vtkSmartPointer<vtkSphereSource>::New(); sphereSource->SetCenter(0.0, 0.0, 0.0); sphereSource->SetRadius(1.0); sphereSource->Update(); vtkSmartPointer<vtkPolyDataMapper> sphereMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); sphereMapper->SetInputConnection(sphereSource->GetOutputPort()); vtkSmartPointer<vtkActor> sphereActor = vtkSmartPointer<vtkActor>::New(); sphereActor->SetMapper(sphereMapper); vtkSmartPointer<vtkImageSliceMapper> imageSliceMapper = vtkSmartPointer<vtkImageSliceMapper>::New(); #if VTK_MAJOR_VERSION <= 5 imageSliceMapper->SetInput(colorImage); #else imageSliceMapper->SetInputData(colorImage); #endif vtkSmartPointer<vtkImageSlice> imageSlice = vtkSmartPointer<vtkImageSlice>::New(); imageSlice->SetMapper(imageSliceMapper); imageSlice->SetPosition(0,0,0); // Setup renderers vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); renderer->AddViewProp(imageSlice); renderer->AddViewProp(sphereActor); renderer->ResetCamera(); // Setup render window vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->SetSize(300, 300); 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->Initialize(); renderWindowInteractor->Start(); return EXIT_SUCCESS; } void CreateColorImage(vtkImageData* const image) { image->SetDimensions(10, 10, 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 < 10; x++) { for(unsigned int y = 0; y < 10; y++) { unsigned char* pixel = static_cast<unsigned char*>(image->GetScalarPointer(x,y,0)); pixel[0] = 255; pixel[1] = 0; pixel[2] = 255; } } }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ImageTranslateExtent) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ImageTranslateExtent MACOSX_BUNDLE ImageTranslateExtent.cxx) target_link_libraries(ImageTranslateExtent ${VTK_LIBRARIES})
Download and Build ImageTranslateExtent¶
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 ImageTranslateExtent and its CMakeLists.txt file. Once the tarball ImageTranslateExtent.tar has been downloaded and extracted,
cd ImageTranslateExtent/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:
./ImageTranslateExtent
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.