ImageWeightedSum

VTKExamples/Cxx/ImageData/ImageWeightedSum


Description

Sum multiple images. Images must be of the same size and type.

Code

ImageWeightedSum.cxx

#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkImageCanvasSource2D.h>
#include <vtkImageWeightedSum.h>
#include <vtkImageMapper3D.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkImageCast.h>
#include <vtkImageMandelbrotSource.h>
#include <vtkImageSinusoidSource.h>

int main(int, char *[])
{
  //create an image
  vtkSmartPointer<vtkImageMandelbrotSource> source1 =
    vtkSmartPointer<vtkImageMandelbrotSource>::New();
  source1->SetWholeExtent(0, 255, 0, 255, 0, 0);
  source1->Update();

  vtkSmartPointer<vtkImageCast> source1Double =
    vtkSmartPointer<vtkImageCast>::New();
  source1Double->SetInputConnection(0, source1->GetOutputPort());
  source1Double->SetOutputScalarTypeToDouble();

  vtkSmartPointer<vtkImageSinusoidSource> source2 =
    vtkSmartPointer<vtkImageSinusoidSource>::New();
  source2->SetWholeExtent(0, 255, 0, 255, 0, 0);
  source2->Update();

  vtkSmartPointer<vtkImageWeightedSum> sumFilter =
    vtkSmartPointer<vtkImageWeightedSum>::New();
  sumFilter->SetWeight(0,.8);
  sumFilter->SetWeight(1,.2);
  sumFilter->AddInputConnection(source1Double->GetOutputPort());
  sumFilter->AddInputConnection(source2->GetOutputPort());

  sumFilter->Update();

  vtkSmartPointer<vtkImageCast> source1CastFilter =
    vtkSmartPointer<vtkImageCast>::New();
  source1CastFilter->SetInputConnection(source1->GetOutputPort());
  source1CastFilter->SetOutputScalarTypeToUnsignedChar();
  source1CastFilter->Update();

  vtkSmartPointer<vtkImageCast> source2CastFilter =
    vtkSmartPointer<vtkImageCast>::New();
  source2CastFilter->SetInputConnection(source2->GetOutputPort());
  source2CastFilter->SetOutputScalarTypeToUnsignedChar();
  source2CastFilter->Update();

  vtkSmartPointer<vtkImageCast> summedCastFilter =
    vtkSmartPointer<vtkImageCast>::New();
  summedCastFilter->SetInputConnection(sumFilter->GetOutputPort());
  summedCastFilter->SetOutputScalarTypeToUnsignedChar();
  summedCastFilter->Update();

  // Create actors
  vtkSmartPointer<vtkImageActor> source1Actor =
    vtkSmartPointer<vtkImageActor>::New();
#if VTK_MAJOR_VERSION <= 5
  source1Actor->SetInput(source1CastFilter->GetOutput());
#else
  source1Actor->GetMapper()->SetInputConnection(source1CastFilter->GetOutputPort());
#endif

  vtkSmartPointer<vtkImageActor> source2Actor =
    vtkSmartPointer<vtkImageActor>::New();
#if VTK_MAJOR_VERSION <= 5
  source2Actor->SetInput(source2CastFilter->GetOutput());
#else
  source2Actor->GetMapper()->SetInputConnection(source2CastFilter->GetOutputPort());
#endif

  vtkSmartPointer<vtkImageActor> summedActor =
    vtkSmartPointer<vtkImageActor>::New();
#if VTK_MAJOR_VERSION <= 5
  summedActor->SetInput(summedCastFilter->GetOutput());
#else
  summedActor->GetMapper()->SetInputConnection(summedCastFilter->GetOutputPort());
#endif

  // There will be one render window
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetSize(600, 300);

  // And one interactor
  vtkSmartPointer<vtkRenderWindowInteractor> interactor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);

  // Define viewport ranges
  // (xmin, ymin, xmax, ymax)
  double leftViewport[4] = {0.0, 0.0, 0.33, 1.0};
  double centerViewport[4] = {0.33, 0.0, .66, 1.0};
  double rightViewport[4] = {0.66, 0.0, 1.0, 1.0};

  // Setup renderers
  vtkSmartPointer<vtkRenderer> leftRenderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderWindow->AddRenderer(leftRenderer);
  leftRenderer->SetViewport(leftViewport);
  leftRenderer->SetBackground(.6, .5, .4);

  vtkSmartPointer<vtkRenderer> centerRenderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderWindow->AddRenderer(centerRenderer);
  centerRenderer->SetViewport(centerViewport);
  centerRenderer->SetBackground(.1, .5, .4);

  vtkSmartPointer<vtkRenderer> rightRenderer =
    vtkSmartPointer<vtkRenderer>::New();
  renderWindow->AddRenderer(rightRenderer);
  rightRenderer->SetViewport(rightViewport);
  rightRenderer->SetBackground(.4, .5, .6);

  leftRenderer->AddActor(source1Actor);
  centerRenderer->AddActor(source2Actor);
  rightRenderer->AddActor(summedActor);

  leftRenderer->ResetCamera();
  centerRenderer->ResetCamera();
  rightRenderer->ResetCamera();

  renderWindow->Render();
  interactor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(ImageWeightedSum)

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

add_executable(ImageWeightedSum MACOSX_BUNDLE ImageWeightedSum.cxx )

target_link_libraries(ImageWeightedSum ${VTK_LIBRARIES})

Download and Build ImageWeightedSum

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

cd ImageWeightedSum/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:

./ImageWeightedSum

WINDOWS USERS

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