NopMap wrote:
Hi! I am trying to create contour lines (and later hillshading) from CGIAR data. They use –32768 as a nodata value for sea areas which results in tremendous cliffs if the data is processed by gdal_contour as it is.
Nop, If the nodata value is not recognised by GDAL you can indicate it explicitly to gdal_contour using the -snodata switch. eg. gdal_contour -snodata -32768 ...
I am looking for a way to replace this nodata value in the geotiffs by a simple 0 value for sea level. It would be great to save the result as a geotiff that can be used as input for contours, hillshading and maybe other calculations. Unfortunately I could not figure out which tool to use for this and how to do it.
The "val_repl.py" (value replace) sample script can be used for this purpose. http://svn.osgeo.org/gdal/trunk/gdal/swig/python/samples/val_repl.py eg. python val_reply.py -innd -32768 -outnd 0 in.tif out.tif Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [email protected] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
