Sorry about some mistakes in the code. The correct one is:

> library(rimage)
> image
size:  458 x 372
type:  rgb
> laplacian_result <- normalize(laplacian(image))
> postscript("laplacian_result.eps")
> plot.imagematrix(laplacian_result)
> dev.off()

Talita

2009/4/11 Talita Perciano <talitaperciano@gmail.com>

> Ok... I'm using the rimage package to manipulate an image. So, the image I
> have in R is of the type imagematrix, which is a matrix with the pixel
> values of the R, G anf B bands. What I'm doing is applying some operation
> (like laplacian filter for example) and plotting the result as an image:
>
> > library(rimage)
> > image
> size:  458 x 372
> type:  rgb
> > laplacian_result <- normalize(laplacian(image))
> > postscript("laplacian_result")
> > plot.imagematrix(laplacian)
> > dev.off()
>
>
> Talita
>
> 2009/4/11 Ben Bolker <bolker@ufl.edu>
>
>>
>>  Do you mean you're importing jpegs or other bitmaps into
>> R and writing them out (possibly with annotation etc.) as
>> PostScript?
>>  Can you give a small example of some sort?  It would
>> help for giving advice.
>>
>>
>>
>>
>> Talita Perciano wrote:
>> > Thank you for the answer. Just to clear things out, I'm generating plots
>> of rgb images.
>> >
>> > Talita
>> >
>> > 2009/4/11 Ben Bolker <bolker@ufl.edu<mailto:bolker@ufl.edu>>
>> >
>> >
>> > Talita Perciano wrote:
>> >> Dear users,
>> >>
>> >> I'm generating some images in R to put into a document that I'm
>> producing
>> >> using Latex. This document in Latex is following a predefined model,
>> which
>> >> does not accept compilation with pdflatex, so I have to compile with
>> latex
>> >> -> dvi -> pdf. Because of that, I have to generate the images in R with
>> >> postscript (I want a vector format to keep the quality). The problem is
>> >> that
>> >> the files of the images are very huge (10MB) and I have many images to
>> put
>> >> into the pdf document.
>> >> I want to know if there is a way to reduce the size of those images
>> >> generated by R using postscript.
>> >>
>> >> Thank you in advance,
>> >>
>> >> Talita
>> >>
>> >>
>> >
>> >  Not in any extremely easy way.  The fundamental problem is
>> > that if you have a whole lot of points in your graph, it's hard
>> > to make them take less file space even if they're overplotted
>> > (and hence not visible in the actual image).
>> >  This has been discussed in various forms on the R list in the past,
>> > but I can't locate those posts easily.  It's a little hard without
>> knowing
>> > what kind of plot you're generating, but I'm assuming that you have
>> > many, many points or lines in the graphic (or a very high-resolution
>> > image plot), and that the details don't all show up in the figure
>> anyway.
>> > A few general strategies:
>> >
>> >  * thin the points down to a random subset
>> >  * use a 2D density plot or hexagonal binning
>> >  * create a  bitmap (PNG) plot, then use image
>> > manipulation tools (ImageMagick etc.) to convert that back to
>> > a PostScript file
>> >  * there was some discussion earlier about whether one
>> > could embed a bitmap of just the internals of the plot, leaving
>> > the axes, labels etc. in vector format, but I don't think that
>> > came to anything
>> >
>> >  good luck
>> >   Ben Bolker
>> >
>> > --
>> > View this message in context:
>> http://www.nabble.com/Help-with-postscript-%28huge-file-size%29-tp23003428p23004309.html
>> > Sent from the R help mailing list archive at Nabble.com.
>> >
>> > ______________________________________________
>> > R-help@r-project.org<mailto:R-help@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
>> > and provide commented, minimal, self-contained, reproducible code.
>> >
>> >
>> >
>> > --
>> > Talita Perciano
>> > Instituto de Matemática e Estatísitca
>> > Universidade de São Paulo - USP
>> > PhD Student in Computer Science
>> > São Paulo, SP, Brazil
>> > Tel: +55 11 8826 7092
>> >
>> > "Success is not final, failure is not fatal: it is the courage to
>> continue that counts."
>> > (Winston Churchill)
>> >
>>
>>
>> --
>> Ben Bolker
>> Associate professor, Biology Dep't, Univ. of Florida
>> bolker@ufl.edu / www.zoology.ufl.edu/bolker
>> GPG key: www.zoology.ufl.edu/bolker/benbolker-publickey.asc
>>
>>
>
>
> --
> Talita Perciano
> Instituto de Matemática e Estatísitca
> Universidade de São Paulo - USP
> PhD Student in Computer Science
> São Paulo, SP, Brazil
> Tel: +55 11 8826 7092
>
> "Success is not final, failure is not fatal: it is the courage to continue
> that counts."
> (Winston Churchill)
>



-- 
Talita Perciano
Instituto de Matemática e Estatísitca
Universidade de São Paulo - USP
PhD Student in Computer Science
São Paulo, SP, Brazil
Tel: +55 11 8826 7092

"Success is not final, failure is not fatal: it is the courage to continue
that counts."
(Winston Churchill)

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