[vtkusers] Advice on preprocessing before surface rendering

[Martin Kavec]

Hi Carl,

thanks for your advice, I'll try the Gaussian filter. I gave a trial to the 
vessel enhancing filter recently published in the ITK's Insight Journal ( 
http://hdl.handle.net/1926/558 ), but I was not able to tweak the parameters 
to get satisfactory results. I had a good hope that it could work.

Thanks,

Martin

On Wednesday 19 September 2007 12:53:18 you wrote:
> Hello Martin,
>
> You can try passing your data through a Gaussian Filter which will smooth
> out some your noise:
>
> smImg = vtkImageGaussianSmooth()
> smImg.SetDimensionality(3)
> smImg.SetRadiusFactors([1.0,1.0,1.0])
> smImg.SetInput(srcImg.GetOutput())
>
> Also you can try setting the threshold in Marching Cubes to a higher value
> to see if you can remove some of the noise that way.
>
> If you decimate that can also alter the look of noise.
>
> I don't know how big your data sets are but I typically have to subsample
> my data which also removes a bit of noise. But I do this step in a seperate
> program outside of VTK.
>
> There are also software packages out there that allow you to manually edit
> image stacks.
>
> Otherwise getting the trade-off between noise and data involves a lot of
> trial and error.
>
> regards,
>
> Henrik