ImageGradientMagnitude
VTKExamples/Cxx/Images/ImageGradientMagnitude
Code
ImageGradientMagnitude.cxx
#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkImageMapper3D.h>
#include <vtkImageGradientMagnitude.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkJPEGReader.h>
#include <vtkImageActor.h>
#include <vtkImageEllipsoidSource.h>
#include <vtkImageCast.h>
int main(int, char *[])
{
// Create an image
vtkSmartPointer<vtkImageEllipsoidSource> source =
vtkSmartPointer<vtkImageEllipsoidSource>::New();
source->SetWholeExtent(0, 20, 0, 20, 0, 0);
source->SetCenter(10,10,0);
source->SetRadius(3,4,0);
source->Update();
vtkSmartPointer<vtkImageGradientMagnitude> gradientMagnitudeFilter =
vtkSmartPointer<vtkImageGradientMagnitude>::New();
gradientMagnitudeFilter->SetInputConnection(source->GetOutputPort());
gradientMagnitudeFilter->Update();
vtkSmartPointer<vtkImageCast> gradientMagnitudeCastFilter =
vtkSmartPointer<vtkImageCast>::New();
gradientMagnitudeCastFilter->SetInputConnection(gradientMagnitudeFilter->GetOutputPort());
gradientMagnitudeCastFilter->SetOutputScalarTypeToUnsignedChar();
gradientMagnitudeCastFilter->Update();
// Create actors
vtkSmartPointer<vtkImageActor> originalActor =
vtkSmartPointer<vtkImageActor>::New();
originalActor->GetMapper()->SetInputConnection(source->GetOutputPort());
vtkSmartPointer<vtkImageActor> gradientMagnitudeActor =
vtkSmartPointer<vtkImageActor>::New();
gradientMagnitudeActor->GetMapper()->SetInputConnection(
gradientMagnitudeCastFilter->GetOutputPort());
// Define viewport ranges
// (xmin, ymin, xmax, ymax)
double originalViewport[4] = {0.0, 0.0, 0.5, 1.0};
double gradientMagnitudeViewport[4] = {0.5, 0.0, 1.0, 1.0};
// Setup renderers
vtkSmartPointer<vtkRenderer> originalRenderer =
vtkSmartPointer<vtkRenderer>::New();
originalRenderer->SetViewport(originalViewport);
originalRenderer->AddActor(originalActor);
originalRenderer->ResetCamera();
originalRenderer->SetBackground(.4, .5, .6);
vtkSmartPointer<vtkRenderer> gradientMagnitudeRenderer =
vtkSmartPointer<vtkRenderer>::New();
gradientMagnitudeRenderer->SetViewport(gradientMagnitudeViewport);
gradientMagnitudeRenderer->AddActor(gradientMagnitudeActor);
gradientMagnitudeRenderer->ResetCamera();
gradientMagnitudeRenderer->SetBackground(.4, .5, .7);
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->SetSize(600, 300);
renderWindow->AddRenderer(originalRenderer);
renderWindow->AddRenderer(gradientMagnitudeRenderer);
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
vtkSmartPointer<vtkInteractorStyleImage> style =
vtkSmartPointer<vtkInteractorStyleImage>::New();
renderWindowInteractor->SetInteractorStyle(style);
renderWindowInteractor->SetRenderWindow(renderWindow);
renderWindowInteractor->Initialize();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(ImageGradientMagnitude)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(ImageGradientMagnitude MACOSX_BUNDLE ImageGradientMagnitude.cxx)
target_link_libraries(ImageGradientMagnitude ${VTK_LIBRARIES})
Download and Build ImageGradientMagnitude
Click here to download ImageGradientMagnitude and its CMakeLists.txt file. Once the tarball ImageGradientMagnitude.tar has been downloaded and extracted,
cd ImageGradientMagnitude/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:
./ImageGradientMagnitude
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.