ITK/Examples/ImageProcessing/CropImageFilter: Difference between revisions

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<div class="floatcenter">[[File:ITK_Examples_Baseline_ImageProcessing_TestCropImageFilter.png]]</div>
{{warning|1=The media wiki content on this page is no longer maintained. The examples presented on the https://itk.org/Wiki/* pages likely require ITK version 4.13 or earlier releasesIn many cases, the examples on this page no longer conform to the best practices for modern ITK versions.
==Description==
}}
This example demonstrates how to crop an image. The SetBoundaryCropSize( cropSize ) method specifies the size of the boundary to be cropped at both the uppper & lower ends of the image - e.g. cropSize/2 pixels will be removed at both upper & lower extents.
 
==Classes Demonstrated==
{{ITKDoxygenURL|CropImageFilter}}
 
==Output==
The original image is displayed on the left. The cropped image is displayed on the right.
 
==CropImageFilter.cxx==
<source lang="cpp">
#include "itkImage.h"
#include "itkImageFileWriter.h"
#include "itkImageFileReader.h"
#include "itkCropImageFilter.h"
 
#include "itksys/SystemTools.hxx"
 
#include "QuickView.h"
 
typedef itk::RGBPixel<unsigned char> PixelType;
typedef itk::Image<PixelType, 2>    ImageType;
 
static void CreateImage(ImageType::Pointer image);
 
int main(int argc, char *argv[])
{
  ImageType::Pointer image = ImageType::New();
  ImageType::SizeType cropSize;
  std::stringstream desc;
 
  if (argc > 1)
    {
    typedef itk::ImageFileReader<ImageType> ReaderType;
    ReaderType::Pointer reader = ReaderType::New();
    reader->SetFileName( argv[1] );
    if (argc > 2)
      {
      cropSize[0] = atoi(argv[2]);
      cropSize[1] = atoi(argv[3]);
      }
    reader->Update();
    image = reader->GetOutput();
    desc << itksys::SystemTools::GetFilenameName(argv[1]);
    }
  else
    {
    CreateImage(image);
    cropSize[0] = 10;
    cropSize[1] = 14;
    desc << "Synthetic image";
    }
 
  typedef itk::CropImageFilter <ImageType, ImageType>
    CropImageFilterType;
 
  CropImageFilterType::Pointer cropFilter
    = CropImageFilterType::New();
  cropFilter->SetInput(image);
  // The SetBoundaryCropSize( cropSize ) method specifies the size of
  // the boundary to be cropped at both the uppper & lower ends of the
  // image eg. cropSize/2 pixels will be removed at both upper & lower
  // extents
 
  cropFilter->SetBoundaryCropSize(cropSize);
 
  // The below three lines are equivalent to the above two lines:
  //ImageType::SizeType halfCropSize = {5,7};
  //cropFilter->SetUpperBoundaryCropSize(halfCropSize);
  //cropFilter->SetLowerBoundaryCropSize(halfCropSize);
 
  QuickView viewer;
  viewer.AddRGBImage(
    image.GetPointer(),
    true,
    desc.str());  
 
  std::stringstream desc2;
  desc2 << "CropImageFilter, crop size = {"
        << cropSize[0] << ", " << cropSize[1] << "}";
  viewer.AddRGBImage(
    cropFilter->GetOutput(),
    true,
    desc2.str()); 
 
  viewer.Visualize();
 
  return EXIT_SUCCESS;
}
 
void CreateImage(ImageType::Pointer image)
{
   // Create an image with 2 connected components
  ImageType::RegionType region;
  ImageType::IndexType start;
  start[0] = 0;
  start[1] = 0;
 
  ImageType::SizeType size;
  unsigned int NumRows = 200;
  unsigned int NumCols = 300;
  size[0] = NumRows;
  size[1] = NumCols;
 
  region.SetSize(size);
  region.SetIndex(start);
 
  image->SetRegions(region);
  image->Allocate();
  image->FillBuffer( itk::NumericTraits<ImageType::PixelType>::Zero);
 
  // Make a rectangle, centered at (100,150) with sides 160 & 240
  // This provides a 20 x 30 border around the square for the crop filter to remove
  for(unsigned int r = 20; r < 180; r++)
    {
    for(unsigned int c = 30; c < 270; c++)
      {
      ImageType::IndexType pixelIndex;
      pixelIndex[0] = r;
      pixelIndex[1] = c;
     
      image->SetPixel(pixelIndex, 200);
      }
    }
}
</source>
 
{{ITKCMakeLists|{{SUBPAGENAME}}}}

Latest revision as of 19:25, 5 June 2019

Warning: The media wiki content on this page is no longer maintained. The examples presented on the https://itk.org/Wiki/* pages likely require ITK version 4.13 or earlier releases. In many cases, the examples on this page no longer conform to the best practices for modern ITK versions.