[Insight-users] Setting image region index to 0 possible

[John]

hi,

I just wrote a filter which is changing the image size and therefor I overloaded
the GenerateOutputInformation(). Additionally I would like to set the index of
the largest possible region of the output image to zero.

Is that possible? If I use the index  of the input region for the output region
I have got no problem. But if I have a output index filled with 0, my filter
isn't working.

It always gives me: 
terminate called after throwing an instance of 'itk::InvalidRequestedRegionError'
  what():  /opt/itk-src/Code/Common/itkDataObject.cxx:397:
Requested region is (at least partially) outside the largest possible region.
Aborted
*** Exited with status: 134 ***

What am I doing wrong?

Thats the not working GenerateOutputInformation:

template < typename TImage >
void StraighteningFilter< TImage >
::GenerateOutputInformation()
{
  Superclass::GenerateOutputInformation();
  
  ImageConstPointer inputImage = this->GetInput();
  ImagePointer outputImage = this->GetOutput();
  
  if ( !inputImage || !outputImage )
  {
    return;
  }  
  
  RegionType inputRegion = inputImage->GetLargestPossibleRegion();
  IndexType inputStart = inputRegion.GetIndex();
  SizeType inputSize = inputRegion.GetSize();
  
  IndexType outputStart;
  outputStart.Fill(0);
  
  SizeType outputSize;
  outputSize[0] = inputSize[0];
  outputSize[1] = m_BelowISOS + 1 + m_AboveISOS;  
  
  RegionType outputRegion;
  outputRegion.SetIndex(outputStart);
  outputRegion.SetSize(outputSize);
  
  outputImage->SetLargestPossibleRegion(outputRegion);
  outputImage->SetSpacing(inputImage->GetSpacing());
  outputImage->SetDirection(inputImage->GetDirection());
  outputImage->SetOrigin(inputImage->GetOrigin());
}

Thank you for any help.

John