[Gdal-dev] Import WorldClim data byte issue

[Frank Warmerdam]

Markus Neteler wrote:
> hi,
> 
> we tried to import the worldclim tile data (generic format BIL)
> from
> http://www.worldclim.org/tiles.php
> 
> Unfortunately the result ranges from 0-65535.
> The page http://www.worldclim.org/format.htm describes
> "The data files (.BIL) are sequential binary files in which
>  values are stored line by line from the upper-left to the
>  lower-right corner. Each cell (pixel) is an integer value
>  (2 bytes; -32768..32767).
> "
> 
> Do I need postprocessing (such as r.mapcalc in GRASS) to
> read these maps or is there another nice trick?

Markus,

The EHDR (ESRI .HDR labelled BIL) driver now supports a keyword in
the file called PIXELTYPE which can have values like SIGNEDINT,
UNSIGNEDINT or FLOATINGPOINT.  So just add a line like the following in
the .hdr file.

PIXELTYPE SIGNEDINT

Future versions of ArcGIS, and possibly 9.2 should also honour this
keyword.  The capability was included in GDAL 1.3.2.

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