[vtkusers] Re: DICOM data resolution reduction

[Goodwin Lawlor]

O'Connor, Aonghus wrote:
> Hi,
> 
> I have been having difficulty reducing the dataset size of a 512*512*87 
> DICOM dataset.
> 
>  
> 
> The memory requirement for such a large set are too demanding on my 
> computer. I’ve set the extent of the dataset to 1 / 4 of the original 
> size and found that I can render this.
> 
> For the whole set I’ve been messing with vtkImageShiftScale and 
> vtkImageShrink3D.
> 
> Here are the steps I take:
> 

Hi Aonghus,

Try using vtkImageMarchingCubes instead of vtkContourFilter
http://www.vtk.org/doc/release/5.0/html/a01553.html - it streams the 
volume in, lowering the memory requirement.

Have a look at vtkSliceCubes too which just reads in 4 slices at a time 
and writes the surface out to disk.
http://www.vtk.org/doc/release/5.0/html/a02018.html


You could also try using vtkDataObject::GlobalReleaseDataFlagOn() which 
prevents each filter hanging on to its data when its finished processing 
it. Your volume needs around 45MB of memory - it shouldn't be unmanageable.

hth

Goodwin