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Cast

vtk-examples/Cxx/Images/Cast


Description

Cast an image to a different type.

Other languages

See (Python), (Java)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

Cast.cxx

#include <vtkImageActor.h>
#include <vtkImageCast.h>
#include <vtkImageData.h>
#include <vtkImageMandelbrotSource.h>
#include <vtkImageMapper3D.h>
#include <vtkInteractorStyleImage.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  // Create a float image
  vtkNew<vtkImageMandelbrotSource> source;
  source->Update();

  std::cout << source->GetOutput()->GetScalarTypeAsString() << std::endl;

  vtkNew<vtkImageCast> castFilter;
  castFilter->SetInputConnection(source->GetOutputPort());
  castFilter->SetOutputScalarTypeToUnsignedChar();
  castFilter->Update();

  // Create an actor
  vtkNew<vtkImageActor> actor;
  actor->GetMapper()->SetInputConnection(castFilter->GetOutputPort());

  // Setup renderer
  vtkNew<vtkRenderer> renderer;
  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("DarkSlateGray").GetData());
  renderer->ResetCamera();

  // Setup render window
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("Cast");

  // Setup render window interactor
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  vtkNew<vtkInteractorStyleImage> style;

  renderWindowInteractor->SetInteractorStyle(style);

  // Render and start interaction
  renderWindowInteractor->SetRenderWindow(renderWindow);
  renderWindow->Render();
  renderWindowInteractor->Initialize();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(Cast)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkImagingCore
  vtkImagingSources
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping Cast: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(Cast MACOSX_BUNDLE Cast.cxx )
  target_link_libraries(Cast PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(Cast MACOSX_BUNDLE Cast.cxx )
  target_link_libraries(Cast PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS Cast
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build Cast

Click here to download Cast and its CMakeLists.txt file. Once the tarball Cast.tar has been downloaded and extracted,

cd Cast/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:

./Cast

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.