[gdal-dev] GTiff optimisation

[Even Rouault]

> I know why raster data made by GDAL show "RAW" string as projection
> information, documentation explain it:
> > When writing coordinate system information to ECW files, many less common
> > coordinate systems are not mapped properly. If you know the ECW name for
> the
> > coordinate system you can force it to be set at creation time with the PROJ
> > and DATUM creation options.
>
> As I did not use DATUM and PROJ creation option GDAL don't add it!

Yes, the mapping between WKT representation and ECW DATUM/PROJ is not perfect,
especially in the WKT -> DATUM/PROJ direction (the other direction is simpler).
You could perhaps try the updated ecw_cs.wkt file attached to ticket
http://trac.osgeo.org/gdal/ticket/4127

>
> Finally I saw that gdal create only an aux.xml file to store his own proj
> information and don't use the projection information from the header file. If
> I
> create this aux.xml file for all of my raster data it could work.

Yes, .aux.xml is a solution that works for most GDAL drivers. But of course, it
will only work in the GDAL-based software world.