[Insight-users] Seg. fault with ReleaseDataFlag and JoinImageFilter

[Benjamin King]

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Hello,

the attached code implements the following pipeline:

reader-->gradient magnitude-->JoinImageFilter
|                                   ^
|                                   |
|-----------------------------------|

When I use reader->ReleaseDataFlagOn(), the program produces a 
segmentation fault on joiner->Update() _unless_ preceeded by a 
gradient->Update(). Please see the comments in the code. I use a fairly 
recent ITK checkout and Linux.

My questions are:

1) Why does this happen? Maybe during Update(), the gradient magnitude 
filter makes the erroneous assumption that the reader's output is still 
valid...

2) Is there a better way to reduce the memory footprint than using 
ReleaseDataFlagOn()?


Thanks for the help,
   Benjamin


#include <iostream>
#include <stdexcept>
#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkGradientMagnitudeImageFilter.h"
#include "itkJoinImageFilter.h"

using std::exception;

int main(int argc, char *argv[])
{
   if (argc != 2)
   {
     std::cout <<
       "Makes a two component image of scalar value vs. gradient 
magnitude\n"
       "\n"
       "USAGE: " << argv[0] << " <volume>\n"
       "  <volume>: ITK volume file, e.g. Analyze. Example: foo.hdr\n"
       << std::endl;
     return 1;
   }

   typedef itk::Image<unsigned short, 3> InputImageType;
   typedef itk::Image<float, 3> DerivativeImageType;

   typedef itk::ImageFileReader<InputImageType> ImageReaderType;
   ImageReaderType::Pointer reader = ImageReaderType::New();
   reader->SetFileName(argv[1]);
   reader->ReleaseDataFlagOn(); // Either insert comment to prevent seg.  
fault...

   typedef itk::GradientMagnitudeImageFilter<InputImageType, 
DerivativeImageType> GradientFilterType;
   GradientFilterType::Pointer gradient = GradientFilterType::New();
   gradient->ReleaseDataFlagOn();
   gradient->SetInput(reader->GetOutput());

   typedef itk::JoinImageFilter<InputImageType, DerivativeImageType> 
JoinFilterType;
   JoinFilterType::Pointer combined = JoinFilterType::New();
   combined->SetInput1(reader->GetOutput());
   combined->SetInput2(gradient->GetOutput());

   try
   {
     // gradient->Update();  // ...or remove this comment to prevent seg. 
fault
     combined->Update();
   }
   catch (itk::ExceptionObject & e)
   {
     std::cerr << "ITK exception: " << e << std::endl;
   }
   catch (std::exception & e)
   {
     std::cerr << "std exception: " << e.what() << std::endl;
   }

   return 0;
}

-- 
Benjamin King
Institut für Medizinische Informatik
Medizinische Hochschule Hannover
Tel.: +49  511  532-2663
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#include <stdexcept>
#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkGradientMagnitudeImageFilter.h"
#include "itkJoinImageFilter.h"

using std::exception;

int main(int argc, char *argv[])
{
  if (argc != 2)
  {
    std::cout << 
      "Makes a two component image of scalar value vs. gradient magnitude\n"
      "\n"
      "USAGE: " << argv[0] << " <volume>\n"
      "  <volume>: ITK volume file, e.g. Analyze. Example: foo.hdr\n"
      << std::endl;
    return 1;
  }

  // Define image types
  typedef itk::Image<unsigned short, 3> InputImageType;
  typedef itk::Image<float, 3> DerivativeImageType;

  // Read Volume
  typedef itk::ImageFileReader<InputImageType> ImageReaderType;
  ImageReaderType::Pointer reader = ImageReaderType::New();
  reader->SetFileName(argv[1]);
  reader->ReleaseDataFlagOn(); // Either insert comment to prevent seg.  fault...

  // Compute gradient magnitude
  typedef itk::GradientMagnitudeImageFilter<InputImageType, DerivativeImageType> GradientFilterType;
  GradientFilterType::Pointer gradient = GradientFilterType::New();
  gradient->ReleaseDataFlagOn();
  gradient->SetInput(reader->GetOutput());

  // Join images
  typedef itk::JoinImageFilter<InputImageType, DerivativeImageType> JoinFilterType;
  JoinFilterType::Pointer combined = JoinFilterType::New();
  combined->SetInput1(reader->GetOutput());
  combined->SetInput2(gradient->GetOutput());

  try
  {
    // gradient->Update();  // ...or remove this comment to prevent seg. fault
    combined->Update();
  }
  catch (itk::ExceptionObject & e)
  {
    std::cerr << "ITK exception: " << e << std::endl;
  }
  catch (std::exception & e)
  {
    std::cerr << "std exception: " << e.what() << std::endl;
  }

  return 0;
}

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