ImageAccumulate
VTKExamples/Cxx/Images/ImageAccumulate
Code¶
ImageAccumulate.cxx
/* * In this example, the resulting histogram has 6 pixels (all of them) in the 3rd bin (value = 2) and zero in the rest of the bins */ #include <vtkVersion.h> #include <vtkImageAccumulate.h> #include <vtkImageData.h> #include <vtkSmartPointer.h> static void CreateImage(vtkSmartPointer<vtkImageData> image); int main(int, char *[] ) { vtkSmartPointer<vtkImageData> image = vtkSmartPointer<vtkImageData>::New(); CreateImage(image); vtkSmartPointer<vtkImageAccumulate> imageAccumulate = vtkSmartPointer<vtkImageAccumulate>::New(); #if VTK_MAJOR_VERSION <= 5 imageAccumulate->SetInputConnection(image->GetProducerPort()); #else imageAccumulate->SetInputData(image); #endif imageAccumulate->SetComponentExtent(0,255,0,0,0,0); imageAccumulate->SetComponentOrigin(0,0,0); imageAccumulate->SetComponentSpacing(1,0,0); // This will count exactly the number of pixels of each color. Use (10,0,0) to make bins of width 10 instead. imageAccumulate->Update(); int dims[3]; imageAccumulate->GetOutput()->GetDimensions(dims); for(vtkIdType bin = 0; bin < dims[0]; ++bin) { std::cout << *(static_cast<int*>(imageAccumulate->GetOutput()->GetScalarPointer(bin, 0, 0))) << " "; } std::cout << std::endl; double mean[3]; imageAccumulate->GetMean(mean); std::cout << "Mean: " << mean[0] << " " << mean[1] << " " << mean[2] << std::endl; return EXIT_SUCCESS; } void CreateImage(vtkSmartPointer<vtkImageData> image) { // Specify the size of the image data image->SetDimensions(2,3,1); //image->SetExtent(0,2,0,3,0,1); #if VTK_MAJOR_VERSION <= 5 image->SetNumberOfScalarComponents(1); image->SetScalarTypeToDouble(); image->AllocateScalars(); #else image->AllocateScalars(VTK_DOUBLE,1); #endif int* dims = image->GetDimensions(); // int dims[3]; // can't do this std::cout << "Dims: " << " x: " << dims[0] << " y: " << dims[1] << " z: " << dims[2] << std::endl; // Fill every entry of the image data with "2.0" for (int z = 0; z < dims[2]; z++) { for (int y = 0; y < dims[1]; y++) { for (int x = 0; x < dims[0]; x++) { double* pixel = static_cast<double*>(image->GetScalarPointer(x,y,z)); pixel[0] = 2.0; } } } }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ImageAccumulate) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ImageAccumulate MACOSX_BUNDLE ImageAccumulate.cxx) target_link_libraries(ImageAccumulate ${VTK_LIBRARIES})
Download and Build ImageAccumulate¶
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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 ImageAccumulate and its CMakeLists.txt file. Once the tarball ImageAccumulate.tar has been downloaded and extracted,
cd ImageAccumulate/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:
./ImageAccumulate
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.