[R-sig-Geo] Reading jpeg and tiff

[ONKELINX, Thierry]

Dear useRs,

I'm trying to read jpeg and GeoTiff with readGDAL() (rgdal package). The
jpeg is about 5.6 MB in size, has 3063 rows and 4870 columns and has 3
bands. The tiff is 3.7 MB, has 15750 rows and 12600 colums and 1 band. I
can't import neither of them in R due to a lack of memory. Although I've
set the memory limit to the max (memory.limit(size =
round(memory.limit()/1048576.0, 2))). I'm running R 2.4.1 on a Win Xp
machine with 2 GB RAM.

So far I managed to read in the data but a lower resolution, which I
don't want. Any suggestions on a more efficient way to import these
files. Solutions based on Spatial-classes are prefered.

Here is the code I'm using now.

library(rgdal)
memory.limit(size = round(memory.limit()/1048576.0, 2))
info <- GDALinfo("d://ferraris0894.jpg")
readGDAL("d://ferraris0894.jpg", output.dim = round(c(info[["rows"]],
info[["columns"]]) / 2))


sessionInfo()
R version 2.4.1 (2006-12-18) 
i386-pc-mingw32 

locale:
LC_COLLATE=Dutch_Belgium.1252;LC_CTYPE=Dutch_Belgium.1252;LC_MONETARY=Du
tch_Belgium.1252;LC_NUMERIC=C;LC_TIME=Dutch_Belgium.1252

attached base packages:
[1] "stats"     "graphics"  "grDevices" "utils"     "datasets"  "tcltk"

[7] "methods"   "base"     

other attached packages:
   rgdal       sp     svIO   R2HTML   svMisc svSocket    svIDE 
 "0.5-8" "0.9-13"  "0.9-5"   "1.58"  "0.9-5"  "0.9-5"  "0.9-5"


Thanks,

Thierry

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Reseach Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be
www.inbo.be 

Do not put your faith in what statistics say until you have carefully
considered what they do not say.  ~William W. Watt
A statistical analysis, properly conducted, is a delicate dissection of
uncertainties, a surgery of suppositions. ~M.J.Moroney