On 06/08/11 19:36, Armin Burger wrote:
thanks for pointing me to the ECW definitions. My main problem are currently the missing ETRS89/GRS80 definitions for several pan-European projections that are missing. Some national projections I need I could already identify and I will try them. If a projection is missing can I add it and GDAL will try to use it when reading and creating ECW files? Regarding the datums I guess I will be limited to the ones available in this list an understood by the ECW library, right?
No, you can add datums and projections to the ecw_cs.wkt file, and GDAL will recognize them. Then, you can submit a patch, like I did a few months ago to add french datums and projections (see <http://trac.osgeo.org/gdal/ticket/3868>).
Is there a way to update an ECW file adding this type of information via GDAL API functions? I know there was a Windows GUI tool from ER Mapper some years a go that could modify some kind of ECW header, but I would need to run this on at least several 100's of files, so a manual approach is not feasible. Or do I need to re-create all ECW's and add the projection options?
The "ECW Header Editor" is still available from Erdas : <http://erdas.com/products/ERDASAPOLLO/ERDASAPOLLOEssentials-ImageWebServer/Downloads.aspx> ER Mapper was also providing a command line tool that you could use in a script, but I don't know if it is still available. (The URL was <http://www.ermapper.com.au/downloads/ecwheader.zip> , but it is not working at this time). If not, you can try a small command line utility I wrote a few years ago (<http://jrepetto.free.fr/ecwhed/>), but you'll have to compile it for Windows.
Jean-Claude _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
