Hi all,
I'm trying to export a resampled dem to Gtiff using r.out.gdal ; I
have no problem exporting a slope and aspect file of the same format
and origin, nor do I have any problem exporting landsat images...but
for some reason I when I export the elevation file it reports that it
has completed without error but upon inspection all I have is an
empty,black image that is 1.6mb.
Trying the same thing with the spearfish data (elevation.10m) yields
the same result....except instead of black, the file is green....
my command for example:
"r.out.gdal input=elevation.10m format=GTiff type=Byte
output=/home/zachary/Desktop/dems/test_1.tif"
If I were to simply change the file to any other raster this works fine....
Can anyone help me figure out why I can't export any DEM?
The "r.out.gdal" export tool will just write out raw elevation
values to the pixels. You can check the min/max values of the raster
with:
gdalinfo -mm test_1.tif
My guess is that the output tif is contains accurate data but, since a
16-bit tiff typically doesn't have a color palette, the rendering
program will usually apply a color ramp (typically black->white) from
low->high which is 0 to 65536 for a 16-bit image. So it really depends
on how the rendering application handles the data. Many programs will
let you alter the color ramp to capture the variability in your data.
"r.colors" and "r.out.tiff" might do the trick.
- matt
On Wed, Feb 27, 2008 at 1:23 PM, Zachary Parisa <zacharyparisa@gmail.com> wrote:
Hi all,
I'm trying to export a resampled dem to Gtiff using r.out.gdal ; I
have no problem exporting a slope and aspect file of the same format
and origin, nor do I have any problem exporting landsat images...but
for some reason I when I export the elevation file it reports that it
has completed without error but upon inspection all I have is an
empty,black image that is 1.6mb.
Trying the same thing with the spearfish data (elevation.10m) yields
the same result....except instead of black, the file is green....
my command for example:
"r.out.gdal input=elevation.10m format=GTiff type=Byte
output=/home/zachary/Desktop/dems/test_1.tif"
If I were to simply change the file to any other raster this works fine....
Can anyone help me figure out why I can't export any DEM?