[GRASSLIST:6701] Re: Export routine

[Otto Dassau]

Am Montag, 2. Mai 2005 21:13 schrieb Jachym Cepicky:
> the best way is r.out.gdal

Dear Nivedita, 

you need to configure GDAL with GRASS Support to be able to export GRASS 
raster maps into ERDAS/Img.

r.out.gdal -l
  VRT: Virtual Raster
  GTiff: GeoTIFF
  [...]  
  ITF: National Imagery Transmission Format
  HFA: Erdas Imagine Images (.img)
  [...]

For many Distributions (SuSE, Debian, Mandrake,...) 'gdal_grass' packages 
(support) can be downloaded as RPM or .deb. as well

see:
http://grass.itc.it/download/index.php
http://www.gdf-hannover.de/software/
...

best wishes 
   Otto

> jachym
>
> On Mon, May 02, 2005 at 12:53:43PM -0400, Nivedita Candade wrote:
> > Hello !
> >
> > I am having problems exporting a grass raster to ERDAS. I have tried
> > these:
> >
> > 1. r.out.erdas: doesn't produce the .img file. Gives me the error "raster
> > has no layers" when I try to open it in ERDAS
> >
> > 2. I tried directly importing the grass file (w/ respective files in
> > cell, cellhd, cats etc. directories) in ERDAS but this method doesn't
> > work. This is the error message when trying to import: "The instruction
> > at
> > "0x78009047" referenced memory at "0x00000000". The memory could not be
> > "read"
> >
> > 3. r.out.ascii: created ascii file and tried to "import" ASCII raster in
> > ERDAS. This works and creates the img file, HOWEVER, it does not maintain
> > classification. I have a classified map w/ 7 classes. Once exported to
> > erdas img file, the numbers are treated as DNs and not classes anymore. I
> > am unable to assign colors or perform accuracy assessment. I am able to
> > open it successfully in ArcGIS but still can't perform accuracy
> > assessment in ArcGIS.
> >
> > 4. r.out.tiff: works but resulting map is not a classified map anymore.
> > it has gray values ranging from 0-255.
> >
> > Anyone knows a method to successfully export a classified map from grass
> > to erdas ?
> >
> > Thanks in advance
> >
> > --
> > Nivedita V. Candade
> > Research Assistant
> > Geospatial Analytics Lab
> > University of South Florida
> > St. Petersburg, FL 33701

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