VTK/Examples/Cxx/Images/CombineImages

This example takes two images and super imposes them. The opacity of each image can be set to control how they are combined.

CombineImages.cxx

#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkJPEGReader.h>
#include <vtkImageData.h>
#include <vtkSmartPointer.h>
#include <vtkImageViewer2.h>
#include <vtkImageBlend.h>
#include <string>

int main ( int argc, char* argv[] )
{
  // Parse input arguments
  if ( argc != 3 )
    {
    std::cerr << "Usage: " << argv[0]
              << " Input1Filename Input2Filename" << std::endl;
    return EXIT_FAILURE;
    }

  std::string input1Filename = argv[1];
  std::string input2Filename = argv[2];

  // Read the images
  vtkSmartPointer<vtkJPEGReader> jPEGReader1 =
    vtkSmartPointer<vtkJPEGReader>::New();
  jPEGReader1->SetFileName ( input1Filename.c_str() );
  
  vtkSmartPointer<vtkJPEGReader> jPEGReader2 =
    vtkSmartPointer<vtkJPEGReader>::New();
  jPEGReader2->SetFileName ( input2Filename.c_str() );

  // Combine the images (blend takes multiple connections on the 0th input port)
  vtkSmartPointer<vtkImageBlend> blend =
    vtkSmartPointer<vtkImageBlend>::New();
  blend->AddInputConnection(jPEGReader1->GetOutputPort());
  blend->AddInputConnection(jPEGReader2->GetOutputPort());
  blend->SetOpacity(0,.5);
  blend->SetOpacity(1,.5);
  
  // Display the result
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();

  vtkSmartPointer<vtkImageViewer2> imageViewer =
    vtkSmartPointer<vtkImageViewer2>::New();
  imageViewer->SetInputConnection(blend->GetOutputPort());
  imageViewer->SetupInteractor(renderWindowInteractor);
  imageViewer->GetRenderer()->ResetCamera();
  imageViewer->GetRenderer()->SetBackground(1,0,0); //red
  
  renderWindowInteractor->Initialize();
  renderWindowInteractor->Start();
  
  return EXIT_SUCCESS;
}

Please try the new VTKExamples website.

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(CombineImages)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(CombineImages MACOSX_BUNDLE CombineImages.cxx)

if(VTK_LIBRARIES)
  target_link_libraries(CombineImages ${VTK_LIBRARIES})
else()
  target_link_libraries(CombineImages vtkHybrid vtkWidgets)
endif()

Download and Build CombineImages

Click here to download CombineImages. and its CMakeLists.txt file.

Once the tarball CombineImages.tar has been downloaded and extracted,

cd CombineImages/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:

./CombineImages

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.

Comments

Display the input images as well as the output (3 renderers side-by-side).