For some of the fancier transforms it may be easier to use an outside tool such as Imagemagick which will do a lot of these things. There is even a C++ interface to imagemagick that may work nicely with packages like Rcpp if you don't want to use an intermediate file.
But jobs like converting to grayscale can be very simple using R itself. Many of the functions that read in images store them as 3 dimensional arrays and you would just need an apply command to change the 3 values for each pixel to a grayscale value (see col2gray in the TeachingDemos package for one way to do this, though loading in the whole package is probably overkill for something this simple). On Fri, Feb 22, 2013 at 1:57 AM, PIKAL Petr <petr.pi...@precheza.cz> wrote: > Thanks. **** > > ** ** > > I tried EBImage several years ago for another problem, but Bioconductor > packages have some difficulties to install in our network/firewall > environment and I am not in a position to change it. It seems to me also an > overkill for such simple task.**** > > ** ** > > jpeg and png seems to me a bit too much simple, without direct possibility > to transform from rgb to grayscale and normalisation.**** > > ** ** > > Anyway, I will give it a try.**** > > ** ** > > Petr**** > > ** ** > > *From:* Greg Snow [mailto:538...@gmail.com] > *Sent:* Friday, February 22, 2013 6:45 AM > *To:* PIKAL Petr > *Cc:* r-help > > *Subject:* Re: [R] package ReadImages**** > > ** ** > > Some possibilities: The EBImage package on Bioconductor; the jpeg and png > packages read jpeg and png images. **** > > ** ** > > On Thu, Feb 21, 2013 at 8:26 AM, PIKAL Petr <petr.pi...@precheza.cz> > wrote:**** > > Dear all > > I prepared some image processing routine which depended on package > ReadImages. Basically I imported image to R, changed rgb to grayscale, > normalised an image made some selections and changed to image by > imagematrix. > > Recently I learned that this package was removed from CRAN and can not be > used in R 3.0.0. > > What options I have now to import image to R, change it to grayscale, make > some computation or selection, change it back to image and plot for visual > inspection. > > Thanks > Petr > > ______________________________________________ > 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.**** > > > > **** > > ** ** > > -- > Gregory (Greg) L. Snow Ph.D. > 538...@gmail.com **** > -- Gregory (Greg) L. Snow Ph.D. 538...@gmail.com [[alternative HTML version deleted]] ______________________________________________ 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.
