Hi,
thank you for your quick answer. I started using ip for temporal filtering, esp. removing low drifts
from the signal. I discovered that I can also apply spatial filtering using ip. The advantages are
obvious to me - it is one step instead of two (using ip and susan_smooth) and it doesn`t need a
change of magnitude of numbers (the 16bit integer issue in susan_smooth).
So the question is basically about the linear Gaussian filtering and the lowpass median filtering -
what do I lose by not using susan?
I guess that can`t be answered in general but only for my data.
That`s why I would like to read more about way the ip-filtering (esp. spatial) works, to understand
what is doing what.
I hope I was more precise this time...
Mareike
Steve Smith wrote:
> Hi,
>
> Yes, susan_smooth is nonlinear spatial smoothing, ip contains various
> options, including lineas Gaussian smoothing, temporal filtering and
> intensity normalisation.
>
> Without knowing what context you are asking about it's hard to answer
> your question - are you talking about smoothing of FMRI data?
>
> Cheers.
>
>
> On 24 Oct 2006, at 15:53, Mareike Menz wrote:
>
>> Dear FSLers,
>>
>> I wonder about about the algorithm ip is using. As far as I understood
>> it is different from susan_smooth - am I right about that?
>> I also read about a difference between FSL and SPM in regard to
>> smoothing/filtering.
>>
>> Maybe you could give me a hint, where to look for information?
>> Is there any reference you could give to me or a technical report I
>> could read? In case it is the susan-paper I`ve got it.
>>
>> Thank you in advance,
>>
>> greetings from Hamburg,
>> Mareike
>>
>>
>> --
>> Mareike Menz
>> NeuroImage Nord Lübeck
>> University Medical Center Hamburg-Eppendorf, Bldg. S10
>> Martinistr. 52
>> 20246 Hamburg
>> Germany
>>
>> +49 40 42803 3683
>> [log in to unmask]
>>
>> --
>>
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>
>
> ---------------------------------------------------------------------------
> Stephen M. Smith, Professor of Biomedical Engineering
> Associate Director, Oxford University FMRIB Centre
>
> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
> +44 (0) 1865 222726 (fax 222717)
> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
> ---------------------------------------------------------------------------
>
>
--
Mareike Menz
NeuroImage Nord Lübeck
University Medical Center Hamburg-Eppendorf, Bldg. S10
Martinistr. 52
20246 Hamburg
Germany
+49 40 42803 3683
[log in to unmask]
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