Hi Martin - option (a).
Cheers, Steve.
On Mon, 22 Aug 2005, Martin Kavec wrote:
> Hi Steve,
>
> I am getting back to this subject with another question.
>
> On Monday 25 July 2005 22:06, Stephen Smith wrote:
> > Hi - this is just in the bits of code that test for whether the USAN
> > (local neighbourhood of similar valued voxels to the centre voxel) is
> > empty or not - these constants represent the value which is generated by
> > the centre voxel itself - which clearly isn't of interest in judging
> > whether the USAN is "empty" - hence this value is first subtracted from
> > the USAN sum. By default, if the USAN is empty, then the algorithm reverts
> > to the median.
>
> If USAN is empty:
>
> (a) median is the only thing applied to the central pixel
>
> or
>
> (b) after removing salt-and-pepper noise, USAN is searched again, and is
> followed by "selective" Gaussian filtering, just like for any pixel with
> non-empty USAN.
>
> Thanks
> Martin
>
--
Stephen M. Smith DPhil
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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