ImageWarp
Description¶
Combining the imaging and visualization pipelines to deform an image in the z-direction. The vtkMergeFilter is used to combine the warped surface with the original color data.
Info
See Figure 10-17 in Chapter 10 the VTK Textbook.
Other languages
See (Python)
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¶
ImageWarp.cxx
/*
* This example shows how to combine data from both the imaging
* and graphics pipelines. The vtkMergeData filter is used to
* merge the data from each together.
*/
#include <vtkActor.h>
#include <vtkBMPReader.h>
#include <vtkCamera.h>
#include <vtkDataSetMapper.h>
#include <vtkImageDataGeometryFilter.h>
#include <vtkImageLuminance.h>
#include <vtkMergeFilter.h>
#include <vtkNamedColors.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkWarpScalar.h>
#include <array>
#include <iomanip>
#include <iostream>
#include <string>
int main(int argc, char* argv[])
{
if (argc < 2)
{
std::cout << "Usage: " << argv[0] << " fileName" << std::endl;
std::cout << "where: fileName is the masonry.bmp file." << std::endl;
return EXIT_FAILURE;
}
std::string fileName = argv[1];
vtkSmartPointer<vtkNamedColors> colors =
vtkSmartPointer<vtkNamedColors>::New();
// Set the background color.
std::array<unsigned char , 4> bkg{{60, 93, 144, 255}};
colors->SetColor("BkgColor", bkg.data());
// Read in an image and compute a luminance value-> The image is extracted
// as a set of polygons (vtkImageDataGeometryFilter). We then will
// warp the plane using the scalar (luminance) values.
//
vtkSmartPointer<vtkBMPReader> reader = vtkSmartPointer<vtkBMPReader>::New();
reader->SetFileName(fileName.c_str());
// Convert the image to a grey scale.
vtkSmartPointer<vtkImageLuminance> luminance =
vtkSmartPointer<vtkImageLuminance>::New();
luminance->SetInputConnection(reader->GetOutputPort());
// Pass the data to the pipeline as polygons.
vtkSmartPointer<vtkImageDataGeometryFilter> geometry =
vtkSmartPointer<vtkImageDataGeometryFilter>::New();
geometry->SetInputConnection(luminance->GetOutputPort());
// Warp the data in a direction perpendicular to the image plane.
vtkSmartPointer<vtkWarpScalar> warp = vtkSmartPointer<vtkWarpScalar>::New();
warp->SetInputConnection(geometry->GetOutputPort());
warp->SetScaleFactor(-0.1);
// Use vtkMergeFilter to combine the original image with the warped geometry.
vtkSmartPointer<vtkMergeFilter> merge =
vtkSmartPointer<vtkMergeFilter>::New();
merge->SetGeometryConnection(warp->GetOutputPort());
merge->SetScalarsConnection(reader->GetOutputPort());
vtkSmartPointer<vtkDataSetMapper> mapper =
vtkSmartPointer<vtkDataSetMapper>::New();
mapper->SetInputConnection(merge->GetOutputPort());
mapper->SetScalarRange(0, 255);
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
// Create the rendering window, renderer, and interactive renderer.
//
vtkSmartPointer<vtkRenderer> ren = vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renWin =
vtkSmartPointer<vtkRenderWindow>::New();
renWin->AddRenderer(ren);
vtkSmartPointer<vtkRenderWindowInteractor> iren =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
iren->SetRenderWindow(renWin);
// Add the actors to the renderer, set the background and size.
ren->AddActor(actor);
ren->ResetCamera();
ren->SetBackground(colors->GetColor3d("BkgColor").GetData());
// ren->GetActiveCamera()->Azimuth(20);
// ren->GetActiveCamera()->Elevation(30);
// ren->ResetCameraClippingRange();
// ren->GetActiveCamera()->Zoom(1.3);
ren->GetActiveCamera()->SetPosition(-100, -130, 325);
ren->GetActiveCamera()->SetFocalPoint(105, 114, -29);
ren->GetActiveCamera()->SetViewUp(0.51, 0.54, 0.67);
ren->ResetCameraClippingRange();
renWin->SetSize(512, 512);
// Render the image.
renWin->Render();
iren->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
project(ImageWarp)
find_package(VTK COMPONENTS
vtkvtkCommonColor
vtkvtkCommonCore
vtkvtkFiltersCore
vtkvtkFiltersGeneral
vtkvtkFiltersGeometry
vtkvtkIOImage
vtkvtkImagingColor
vtkvtkInteractionStyle
vtkvtkRenderingContextOpenGL2
vtkvtkRenderingCore
vtkvtkRenderingFreeType
vtkvtkRenderingGL2PSOpenGL2
vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
message("Skipping ImageWarp: ${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(ImageWarp MACOSX_BUNDLE ImageWarp.cxx )
target_link_libraries(ImageWarp PRIVATE ${VTK_LIBRARIES})
else ()
# include all components
add_executable(ImageWarp MACOSX_BUNDLE ImageWarp.cxx )
target_link_libraries(ImageWarp PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS ImageWarp
MODULES ${VTK_LIBRARIES}
)
endif ()
Download and Build ImageWarp¶
Click here to download ImageWarp and its CMakeLists.txt file. Once the tarball ImageWarp.tar has been downloaded and extracted,
cd ImageWarp/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:
./ImageWarp
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.