[R-sig-Geo] ENVI data and R

[Guy Serbin]

Thank you all for the help- I successfully read an image into R using
these methods.

I did, however, encounter some problems when loading a hyperspectral
image cube into R as it was unable to allocate the 2.9 GB of volatile
memory that it needed.

Is there a way to improve memory management by R, so that it only
reads in the data when actually needed for processing, e.g., only read
in the bands I need, or conversely read in spectra on a per-pixel
basis?

Guy

On Tue, Jul 29, 2008 at 4:05 PM, PUJAN RAJ REGMI
<regmi_pujan at hotmail.com> wrote:
>
> This might help to mange the orientation of image:
>
> # To read ENVI format
> cir.image<-("YOUR_ENVI_FILE")
> CIR.envi<-read.ENVI(cir.image,headerfile=paste(cir.image,".hdr",sep=""))
> # To Show image
> CIR.envi.band1<-CIR.envi[,,1]
> CIR.envi.band1.s<-CIR.envi.band1[order(nrow(CIR.envi.band1):1),]
> CIR.envi.band1.t<-t(CIR.envi.band1.s)
> image(CIR.envi.band1.t,main="")
> mtext("Raw Matrix ENVI Image for Band1", side=3,line=2, font=3,cex=1.25)
>
> Pujan
> ________________________________
>> From: andrew.niccolai at yale.edu
>> To: guy.serbin at gmail.com; R-sig-Geo at stat.math.ethz.ch
>> Date: Tue, 29 Jul 2008 14:24:04 -0400
>> Subject: Re: [R-sig-Geo] ENVI data and R
>>
>> This code might help:
>>
>>
>> ############################################################################
>> ####
>>
>> ############################################################################
>> ####
>> ## Read in envi file
>> cir.image <- "C:/YOUR_ENVI_FILE"
>> CIR.envi = read.ENVI(cir.image, headerfile=paste(cir.image,".hdr",
>> sep=""))
>>
>>
>> ############################################################################
>> ####
>>
>> ############################################################################
>> ####
>> ## Show image
>> CIR.envi.band1 <- CIR.envi[,,1]
>> image(CIR.envi.band1, main="")
>> mtext("Raw Matrix ENVI Image for Band 1", side=3,line = 2, font=3,
>> cex=1.25)
>>
>>
>> ############################################################################
>> ####
>>
>> ############################################################################
>> ####
>>
>> Andrew Niccolai
>> Doctoral Candidate
>> Yale School of Forestry
>>
>>
>>
>> -----Original Message-----
>> From: r-sig-geo-bounces at stat.math.ethz.ch
>> [mailto:r-sig-geo-bounces at stat.math.ethz.ch] On Behalf Of Guy Serbin
>> Sent: Tuesday, July 29, 2008 12:55 PM
>> To: R-sig-Geo at stat.math.ethz.ch
>> Subject: [R-sig-Geo] ENVI data and R
>>
>> Hi,
>>
>> I was wondering if anyone knows how to either call up R functions from
>> within IDL, or conversely read ENVI image data into R. If you have
>> any advice I'd greatly appreciate it.
>>
>> Thanks,
>> Guy Serbin
>>
>> --
>> Guy Serbin, Ph.D.
>> Research Soil Scientist
>> Hydrology and Remote Sensing Lab
>> Bldg 007 Rm 104 BARC-West
>> 10300 Baltimore Blvd
>> Beltsville, MD 20705-2350 USA
>> +1(301)504-5250 guy.serbin at gmail.com
>>
>> _______________________________________________
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>>
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>
> ________________________________
> Stay in touch when you're away with Windows Live Messenger. IM anytime
> you're online.



-- 
Guy Serbin, Ph.D.
Research Soil Scientist
Hydrology and Remote Sensing Lab
Bldg 007 Rm 104 BARC-West
10300 Baltimore Blvd
Beltsville, MD 20705-2350 USA
+1(301)504-5250 guy.serbin at gmail.com