[Insight-users] pixel access of filter output image

[Jie Zhu]

Thank you, Luis.
-Jie


On Fri, 29 Oct 2004 15:16:20 -0400, Luis Ibanez <luis.ibanez at kitware.com> wrote:
> 
> Hi Jie,
> 
> 1) You shouldn't take the region for the iterator from
>    the RequestedRegion of the filter.
> 
> 2) You don't seem to need to use the LinearIterators,
>    it will be simpler to use the plain ImageRegionIterator.
> 
> Like:
> 
>    ImageType::Pointer image = smoothing->GetOutput();
> 
>    typedef itk::ImageRegionIterator<ImageType> IteratorType;
> 
>    IteratorType it( image, image->GetBufferedRegion() );
> 
>    it.GoToBegin();
>    while( !it.IsAtEnd() )
>      {
>      PixelType value = it.Get();
>      ++it;
>      }
> 
>   Regards,
> 
>      Luis
> 
> -----------------
> 
> 
> Jie Zhu wrote:
> 
> > Hi All,
> > I am having trouble when I try to access pixels in an image output by
> > a smoothing (or other types of ) filter.
> > I have a smoothing filter like below and I gave it some input image, I
> > checked the output image and it is working fine. But if I try to
> > access pixels in this output image using iterators it just crashes.
> > Why is this happening?
> > Thanks a lot,
> > Jie
> >
> >   typedef   float           InternalPixelType;
> >   const     unsigned int    Dimension = 2;
> >   typedef itk::Image< InternalPixelType, Dimension >  InternalImageType;
> >
> >   typedef   itk::CurvatureAnisotropicDiffusionImageFilter<
> >                                InternalImageType,
> >                                InternalImageType >  SmoothingFilterType;
> >
> >   SmoothingFilterType::Pointer smoothing = SmoothingFilterType::New();
> >   smoothing->SetInput( reader->GetOutput() );
> >
> >   typedef itk::ImageLinearIteratorWithIndex< InternalImageType > IteratorType;
> >
> >   IteratorType it( smoothing->GetOutput(), smoothing->GetRequestedRegion() );
> >   it.SetDirection(0);
> >   for ( it.GoToBegin(); ! it.IsAtEnd();it.NextLine()){
> >     it.GoToBeginOfLine();
> >     float pixelValue;
> >     InternalImageType::IndexType  tmpIndx;
> >     while ( ! it.IsAtEndOfLine() ){
> >       pixelValue = it.Get();   //<--------------------- crashes here
> >       ++it;
> >     }
> >   }
> > _______________________________________________
> 
> 
> > Insight-users mailing list
> > Insight-users at itk.org
> > http://www.itk.org/mailman/listinfo/insight-users
> >
> >
> 
> 


-- 
Jie Zhu
Cornell University