[mapserver-users] Unix and RGB - GRID in mapfile

[Frank Warmerdam]

On Thu, Mar 18, 2010 at 6:56 AM, Simone Frigerio
<simone.frigerio at univie.ac.at> wrote:
> Hi,
> I need to manage huge file raster inside mapfile. Different kind of
> compression are available and I'm trying different way. Two questions on
> topic:
> 1) ECW andJPEG200 format are supported if I use win environment.
> Transferring on Unix environment, probably a GDAL new library has to be
> written, because actually it doesn't work. Is it true?

Simone,

ECW and JPEG2000 support is available on Windows and Linux.
However, they are optional components of the library, and depending
on where you are getting your binaries they may not be included.  If
not you may need to rebuild yourself to include them and they do
depend on external libraries.

You can use "gdalinfo --format ecw" to check for a specific
driver or "gdalinfo --formats" to see a list of all supported
drivers in your build.

> 2) trying with GRID format should be interesting, especially for 1 band
> raster like DTM or DEM:
> ex.:   LAYER
> NAME "grid"
> TYPE RASTER
> DATA "GRID/1956gridc1/w001001.adf"
> ...
> END
>
> At the end no problem, it's correctly visualize. But I have a lot of RGB
> raster to manage. So I if I convert in grid the result in "data" folder is:
> folder
> folderc1
> folderc2
> folderc3
> info
> file.aux
> file.rrd
>
> Inside each folder I find w001001.adf as request to visualize. I use it and
> it works perfectly, but only with one band. How can I manage 3 bands in this
> way, to visualize correctly an RGB raster?

I am not aware of direct support for treating multiple grids
as a single dataset.  One workaround is to create a virtual
dataset referencing each of these files as a band.  If you
want to pursue that you could review the "virtual file
tutorial" at:

  http://www.gdal.org/gdal_vrttut.html

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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