ResizeImageDemo
VTKEx/Cxx/Images/ResizeImageDemo
Question
If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum
Code¶
ResizeImageDemo.cxx
#include <vtkImageResize.h>
#include <vtkImageSincInterpolator.h>
#include <vtkSmartPointer.h>
#include <vtkActor2D.h>
#include <vtkCamera.h>
#include <vtkImageActor.h>
#include <vtkImageCanvasSource2D.h>
#include <vtkImageData.h>
#include <vtkImageMapper3D.h>
#include <vtkImageReader2.h>
#include <vtkImageReader2Factory.h>
#include <vtkInteractorStyleImage.h>
#include <vtkNamedColors.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkTextMapper.h>
#include <vtkTextProperty.h>
#include <string>
#include <vector>
int main(int argc, char* argv[])
{
vtkSmartPointer<vtkImageData> imageData;
double factor = .5;
int newSize[2];
// Verify input arguments
if (argc > 1)
{
// Read the image
auto readerFactory = vtkSmartPointer<vtkImageReader2Factory>::New();
vtkSmartPointer<vtkImageReader2> reader;
reader.TakeReference(readerFactory->CreateImageReader2(argv[1]));
reader->SetFileName(argv[1]);
reader->Update();
imageData = reader->GetOutput();
if (argc > 2)
{
factor = atof(argv[2]);
}
}
else
{
vtkSmartPointer<vtkImageCanvasSource2D> canvasSource =
vtkSmartPointer<vtkImageCanvasSource2D>::New();
canvasSource->SetExtent(0, 100, 0, 100, 0, 0);
canvasSource->SetScalarTypeToUnsignedChar();
canvasSource->SetNumberOfScalarComponents(3);
canvasSource->SetDrawColor(127, 127, 100);
canvasSource->FillBox(0, 100, 0, 100);
canvasSource->SetDrawColor(100, 255, 255);
canvasSource->FillTriangle(10, 10, 25, 10, 25, 25);
canvasSource->SetDrawColor(255, 100, 255);
canvasSource->FillTube(75, 75, 0, 75, 5.0);
canvasSource->Update();
imageData = canvasSource->GetOutput();
}
std::cout << "Original dimensions: " << imageData->GetDimensions()[0] << ", "
<< imageData->GetDimensions()[1] << std::endl;
newSize[0] = imageData->GetDimensions()[0] * factor;
newSize[1] = imageData->GetDimensions()[1] * factor;
std::cout << "New dimensions: " << newSize[0] << ", " << newSize[1]
<< std::endl;
auto colors = vtkSmartPointer<vtkNamedColors>::New();
// One camera for all
auto camera = vtkSmartPointer<vtkCamera>::New();
// Create one text property for all
auto textProperty = vtkSmartPointer<vtkTextProperty>::New();
textProperty->SetFontSize(20);
textProperty->SetJustificationToCentered();
textProperty->SetColor(0.3, 0.3, 0.3);
// Setup render window
auto renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
std::vector<vtkSmartPointer<vtkRenderer>> renderers;
for (int i = -1; i <= 10; ++i)
{
auto interpolator = vtkSmartPointer<vtkImageSincInterpolator>::New();
auto windowFunction = i;
interpolator->UseWindowParameterOn();
auto resize = vtkSmartPointer<vtkImageResize>::New();
resize->SetInputData(imageData);
resize->SetInterpolator(interpolator);
resize->SetOutputDimensions(newSize[0], newSize[1], 1);
resize->InterpolateOn();
// Create an image actor to display the image
auto imageActor = vtkSmartPointer<vtkImageActor>::New();
imageActor->GetMapper()->SetInputConnection(resize->GetOutputPort());
imageActor->InterpolateOff();
// Create textActors
auto textMapper = vtkSmartPointer<vtkTextMapper>::New();
textMapper->SetTextProperty(textProperty);
if (windowFunction < 0)
{
resize->InterpolateOff();
textMapper->SetInput("Nearest neighbor");
}
else
{
resize->InterpolateOn();
interpolator->SetWindowFunction(windowFunction);
textMapper->SetInput(interpolator->GetWindowFunctionAsString());
}
auto textActor = vtkSmartPointer<vtkActor2D>::New();
textActor->SetMapper(textMapper);
textActor->SetPosition(100, 16);
// Setup renderer
auto renderer = vtkSmartPointer<vtkRenderer>::New();
renderer->AddActor(imageActor);
renderer->AddActor(textActor);
;
renderer->SetBackground(colors->GetColor3d("Burlywood").GetData());
renderer->SetActiveCamera(camera);
renderer->ResetCamera();
renderer->GetActiveCamera()->Dolly(5);
renderer->ResetCameraClippingRange();
renderers.push_back(renderer);
renderWindow->AddRenderer(renderer);
}
// Setup viewports for the renderers
int rendererSize = 200;
unsigned int xGridDimensions = 4;
unsigned int yGridDimensions = 3;
renderWindow->SetSize(rendererSize * xGridDimensions,
rendererSize * yGridDimensions);
for (int row = 0; row < static_cast<int>(yGridDimensions); row++)
{
for (int col = 0; col < static_cast<int>(xGridDimensions); col++)
{
int index = row * xGridDimensions + col;
// (xmin, ymin, xmax, ymax)
double viewport[4] = {static_cast<double>(col) * rendererSize /
(xGridDimensions * rendererSize),
static_cast<double>(yGridDimensions - (row + 1)) *
rendererSize / (yGridDimensions * rendererSize),
static_cast<double>(col + 1) * rendererSize /
(xGridDimensions * rendererSize),
static_cast<double>(yGridDimensions - row) *
rendererSize /
(yGridDimensions * rendererSize)};
renderers[index]->SetViewport(viewport);
}
}
// Setup render window interactor
auto renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
auto style = vtkSmartPointer<vtkInteractorStyleImage>::New();
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(ResizeImageDemo)
find_package(VTK COMPONENTS
vtkvtkCommonColor
vtkvtkCommonCore
vtkvtkCommonDataModel
vtkvtkIOImage
vtkvtkImagingCore
vtkvtkImagingSources
vtkvtkInteractionStyle
vtkvtkRenderingContextOpenGL2
vtkvtkRenderingCore
vtkvtkRenderingFreeType
vtkvtkRenderingGL2PSOpenGL2
vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
message("Skipping ResizeImageDemo: ${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(ResizeImageDemo MACOSX_BUNDLE ResizeImageDemo.cxx )
target_link_libraries(ResizeImageDemo PRIVATE ${VTK_LIBRARIES})
else ()
# include all components
add_executable(ResizeImageDemo MACOSX_BUNDLE ResizeImageDemo.cxx )
target_link_libraries(ResizeImageDemo PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS ResizeImageDemo
MODULES ${VTK_LIBRARIES}
)
endif ()
Download and Build ResizeImageDemo¶
Click here to download ResizeImageDemo and its CMakeLists.txt file. Once the tarball ResizeImageDemo.tar has been downloaded and extracted,
cd ResizeImageDemo/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:
./ResizeImageDemo
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.