ITK/Examples/ImageProcessing/AbsImageFilter

From KitwarePublic

Jump to: navigation, search
ITK Examples Baseline ImageProcessing TestAbsImageFilter.png

This example demonstrates how to compute the absolute value of each pixel in an image. The output shows the input image and the absolute value image. The input image, by necessity of this demonstration, has negative pixel values. This type of image is impossible to display directly, so it is scaled and shifted before being displayed so its values are in the range (0,255).

Contents

AbsImageFilter.cxx

#include "itkImage.h"
#include "itkImageFileWriter.h"
#include "itkRescaleIntensityImageFilter.h"
#include "itkAbsImageFilter.h"
 
#include "QuickView.h"
 
typedef itk::Image<unsigned char, 2>  UnsignedCharImageType;
typedef itk::Image<float, 2>  FloatImageType;
 
static void CreateImage(FloatImageType::Pointer image);
 
int main(int, char *[])
{
  FloatImageType::Pointer image = FloatImageType::New();
  CreateImage(image);
 
  // Take the absolute value of the image
  typedef itk::AbsImageFilter <FloatImageType, FloatImageType>
          AbsImageFilterType;
 
  AbsImageFilterType::Pointer absFilter
          = AbsImageFilterType::New ();
  absFilter->SetInput(image);
 
  QuickView viewer;
  viewer.AddImage<FloatImageType>(image);
  viewer.AddImage<FloatImageType>(absFilter->GetOutput());
  viewer.Visualize();
 
  return EXIT_SUCCESS;
}
 
void CreateImage(FloatImageType::Pointer image)
{
  // Create an image with negative values
  FloatImageType::RegionType region;
  FloatImageType::IndexType start;
  start[0] = 0;
  start[1] = 0;
 
  FloatImageType::SizeType size;
  size[0] = 200;
  size[1] = 300;
 
  region.SetSize(size);
  region.SetIndex(start);
 
  image->SetRegions(region);
  image->Allocate();
 
  itk::ImageRegionIterator<FloatImageType> imageIterator(image,region);
 
  while(!imageIterator.IsAtEnd())
    {
    imageIterator.Set(imageIterator.GetIndex()[0] - imageIterator.GetIndex()[1]);
    ++imageIterator;
    }
 
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)
 
project(AbsImageFilter)
 
find_package(ItkVtkGlue REQUIRED)
include(${ItkVtkGlue_USE_FILE})
 
add_executable(AbsImageFilter AbsImageFilter.cxx)
target_link_libraries(AbsImageFilter
  ItkVtkGlue vtkHybrid ${VTK_LIBRARIES} ${ITK_LIBRARIES})

Building All of the Examples

Many of the examples in the ITK Wiki Examples Collection require VTK. You can build all of the the examples by following these instructions. If you are a new VTK user, you may want to try the Superbuild which will build a proper ITK and VTK.

ItkVtkGlue

If you download the entire ITK Wiki Examples Collection, the ItkVtkGlue directory will be included and configured. If you wish to just build a few examples, then you will need to download ItkVtkGlue and build it. When you run cmake it will ask you to specify the location of the ItkVtkGlue binary directory.

Retrieved from "http://www.itk.org/Wiki/ITK/Examples/ImageProcessing/AbsImageFilter"
Personal tools