JPEGWriter

VTKEx/Cxx/IO/JPEGWriter

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Question

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Code¶

JPEGWriter.cxx

#include <vtkSmartPointer.h>
#include <vtkImageCanvasSource2D.h>
#include <vtkJPEGWriter.h>

int main(int vtkNotUsed(argc), char* vtkNotUsed(argv)[])
{
  std::string outputFilename = "output.jpg";

  // Create a 100x100 image to save into the jpeg file
  int extent[6] = { 0, 99, 0, 99, 0, 0 };
  vtkSmartPointer<vtkImageCanvasSource2D> imageSource =
    vtkSmartPointer<vtkImageCanvasSource2D>::New();
  imageSource->SetExtent( extent );
  imageSource->SetScalarTypeToUnsignedChar(); // vtkJPEGWriter only accepts unsigned char input
  imageSource->SetNumberOfScalarComponents( 3 ); // 3 color channels: Red, Green and Blue

  // Fill the whole image with a blue background
  imageSource->SetDrawColor( 0, 127, 255 );
  imageSource->FillBox( extent[0], extent[1], extent[2], extent[3] );

  // Paint a 30x30 white square into the image
  imageSource->SetDrawColor( 255, 255, 255 );
  imageSource->FillBox( 40, 70, 20, 50 );

  vtkSmartPointer<vtkJPEGWriter> writer =
    vtkSmartPointer<vtkJPEGWriter>::New();
  writer->SetFileName( outputFilename.c_str() );
  writer->SetInputConnection( imageSource->GetOutputPort() );
  writer->Write();

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(JPEGWriter)

find_package(VTK COMPONENTS 
  vtkvtkCommonCore
  vtkvtkIOImage
  vtkvtkImagingSources QUIET)
if (NOT VTK_FOUND)
  message("Skipping JPEGWriter: ${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(JPEGWriter MACOSX_BUNDLE JPEGWriter.cxx )
  target_link_libraries(JPEGWriter PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(JPEGWriter MACOSX_BUNDLE JPEGWriter.cxx )
  target_link_libraries(JPEGWriter PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS JPEGWriter
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build JPEGWriter¶

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

cd JPEGWriter/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:

./JPEGWriter

WINDOWS USERS

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