[vtk-developers] Re: [vtkusers] Bug in vtkExtractVOI

[Berk Geveci]

Please wait until Charles can take a look at the problem before
applying a patch. I know he has done many changes to the extract
filters to fix problems which occur when using them in parallel.

-Berk

On Wed, 2003-04-23 at 11:43, bryan cole wrote:
> 
> > Maybe I looked to quickly.  One could keep the origin where it is, and
> > make sure the extent takes into account the extraction, or "move" the
> > origin so that extracted points are still at their correct positions. 
> > It then seems that the previous "working" version of vtkExtractVOI did
> > the latter which is obviously also good.
> > 
> > Could you perhaps post your patch?
> 
> A patch is attached (the result of 'cvs diff -u4' against todays CVS).
> It would be good to understand what 'lawcc' was aiming for when the
> previous changes to this filter were made, before using the patch to
> restore the old behaviour.
> 
> Bryan
> 
> -- 
> Bryan Cole
> Teraview Ltd., 302-304 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, United Kingdom.
> tel: +44 (1223) 435380 / 435386 (direct-dial) fax: +44 (1223) 435382
> ----
> 

> ? BEC-ExtractVOI.patch
> Index: Imaging/vtkExtractVOI.cxx
> ===================================================================
> RCS file: /cvsroot/VTK/VTK/Imaging/vtkExtractVOI.cxx,v
> retrieving revision 1.34
> diff -u -4 -r1.34 vtkExtractVOI.cxx
> --- Imaging/vtkExtractVOI.cxx	17 Jan 2003 14:31:08 -0000	1.34
> +++ Imaging/vtkExtractVOI.cxx	23 Apr 2003 15:25:52 -0000
> @@ -116,15 +116,15 @@
>        outDims[i] = 1;
>        }
>      }
>  
> -  // This makes sense for sample rates of 1, 1, 1.
> -  wholeExtent[0] = voi[0];
> -  wholeExtent[1] = voi[0] + outDims[0] - 1;
> -  wholeExtent[2] = voi[2];
> -  wholeExtent[3] = voi[2] + outDims[1] - 1;
> -  wholeExtent[4] = voi[4];
> -  wholeExtent[5] = voi[4] + outDims[2] - 1;
> +  // reverting to 'old' behaviour for output extents and origin
> +  wholeExtent[0] = 0;
> +  wholeExtent[1] = outDims[0] - 1;
> +  wholeExtent[2] = 0;
> +  wholeExtent[3] = outDims[1] - 1;
> +  wholeExtent[4] = 0;
> +  wholeExtent[5] = outDims[2] - 1;
>    
>    output->SetWholeExtent( wholeExtent );
>  }
>  
> @@ -200,9 +200,9 @@
>        outDims[i] = 1;
>        }
>  
>      outAR[i] = ar[i] * this->SampleRate[i];
> -    outOrigin[i] = origin[i] + voi[2*i]*ar[i] - outExt[2*i]*outAR[i];
> +    outOrigin[i] = origin[i] + voi[2*i]*ar[i];
>      outSize *= outDims[i];
>      }
>    
>    output->SetSpacing(outAR);