[Insight-users] CannyEdgeDetectionImageFilter GraftOutput() bug?

[Karthik Krishnan]

Thanks. That was  a bug. There was no need for the output to be 
allocated. Its fixed in CVS.

How were you trying to graft the output ?

thanks
karthik

Quan Chen wrote:

> I was trying to use GraftOutput() to set the output of 
> CannyEdgeDetectionImageFilter.  However, I find that the image does 
> not change.  I did same thing for other filters like Sigmoid and 
> AnisotropicDiffusion, and they worked well.  If I 
> use  g_OutputImage=cannyFilter->GetOutput(); g_OutputImage->DisconnectPipeline(); 
> it worked well. 
>  
> I read the CannyEdgeDetection code for a while.  Because I am still 
> not familiar with the ITK architecture, I am not sure about my 
> findings.  But it seems to me that the beginning of the GenerateData() 
> function just re-allocate the output buffer:
> template< class TInputImage, class TOutputImage >
> void
> CannyEdgeDetectionImageFilter< TInputImage, TOutputImage >
> ::GenerateData()
> {
>   // Need to allocate output buffer
>   typename OutputImageType::Pointer output = this->GetOutput();
>   output->SetBufferedRegion(output->GetRequestedRegion());
>   output->Allocate();
>  
>  
> And at last line
>  
>   this->GraftOutput(m_UpdateBuffer);
>  
> Sets the output buffer to be m_UpdateBuffer.
> Both m_UpdateBuffer and m_UpdateBuffer1 was allocated in 
> AllocateUpdateBuffer():
>  
>
> template <class TInputImage, class TOutputImage>
> void
> CannyEdgeDetectionImageFilter<TInputImage, TOutputImage>
> ::AllocateUpdateBuffer()
> {
>   // The update buffer looks just like the input.
>
>   typename TInputImage::ConstPointer input = this->GetInput();
>
>   m_UpdateBuffer->CopyInformation( input );
>   m_UpdateBuffer->SetRequestedRegion(input->GetRequestedRegion());
>   m_UpdateBuffer->SetBufferedRegion(input->GetBufferedRegion());
>   m_UpdateBuffer->Allocate();
>  
>   m_UpdateBuffer1->CopyInformation( input );
>   m_UpdateBuffer1->SetRequestedRegion(input->GetRequestedRegion());
>   m_UpdateBuffer1->SetBufferedRegion(input->GetBufferedRegion());
>   m_UpdateBuffer1->Allocate(); 
> }
>
> Can anyone from development team confirm it is sth wrong with the 
> code?  Or it just I use it incorrectly.
>
>  
>
>  
>  
>
>------------------------------------------------------------------------
>
>_______________________________________________
>Insight-users mailing list
>Insight-users at itk.org
>http://www.itk.org/mailman/listinfo/insight-users
>  
>