[R] 2D filter in R?

[David Winsemius]

On Jan 11, 2012, at 6:21 PM, Michael wrote:

> Okay thanks guys!
>
> I was actually looking for image processing libraries in R.
>
> Specifically, I am looking for something like "filter2d" for
> images(pixels)...
>
> (speed is not a concern for me, since my images are really small,  
> 200x200,
> etc.)
>
> And in fact, these are not images, these are 2d matrix numbers(i.e.  
> numbers
> in a matrix format), I just wanted to smooth them.
>
> Any more pointers?

Besides the huge amount of spatial regression material that you should  
have found by looking up links from the 'spatstat' citation (and the  
Geospatial Task View:  http://cran.r-project.org/web/views/ 
Spatial.html), you should consider looking for packages and websites  
the deal with functional MRI (fMRI). I also think there may be value  
in looking at package 'locfit' and the 'mgcv' package, although they  
may need special coercion to apply the kernels you expressed interest  
in using.

On my machine this brings up the biOps package:

??"image processing"

And this is the same search with RSiteSearch

201 hits from:
http://search.r-project.org/cgi-bin/namazu.cgi?query=%22image+processing%22&max=100&result=normal&sort=score&idxname=functions&idxname=Rhelp08&idxname=Rhelp10&idxname=Rhelp02

-- 
David.
>
> Thanks a lot!
>
> On Wed, Jan 11, 2012 at 5:18 PM, Bert Gunter  
> <gunter.berton at gene.com> wrote:
>
>> ?loess   ## in base R
>> does 2d filtering , though it's not a Gaussian one
>>
>> -- Bert
>>
>> On Wed, Jan 11, 2012 at 3:00 PM, Rolf Turner <rolf.turner at xtra.co.nz>
>> wrote:
>>> On 12/01/12 09:17, Michael wrote:
>>>>
>>>> Hi all,
>>>>
>>>> I am looking for a command for doing 2D filtering (rectangular or
>>>> Gaussian) in R...
>>>>
>>>> I have looked at ksmooth, filter and convolve but they seem to be  
>>>> 1D...
>>>>
>>>> Any thoughts?
>>>>
>>>> Thanks a lot!
>>>
>>>
>>> I'm not sure what you really need/want to do, but you might have a  
>>> look
>>> at "smooth.ppp" (and possibly "density.ppp") from the "spatstat"  
>>> package.
>>>
>>>   cheers,
>>>
>>>       Rolf Turner
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html 
>> >
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>>
>> --
>>
>> Bert Gunter
>> Genentech Nonclinical Biostatistics
>>
>> Internal Contact Info:
>> Phone: 467-7374
>> Website:
>>
>> http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm
>>
>
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>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT