[gdal-dev] Create copy without any bands

[Frank Warmerdam]

Tim Keitt wrote:
> How about:

Tim,

I don't really like!  I think instead it would be better to have
a method/function to copy a variety of types of metadata - possibly
taking some flags to control what should be copied.  Perhaps something
that works similar to the GDALPamDataset::CloneInfo() and
GDALPamRasterBand::CloneInfo() methods?

There is value in a helper to copy the various sorts of metadata
(including georeferencing, color tables, etc) but there are also a
wide variety of situations for use and it is hard to make something
that serves most or all of them.  I have, till now, tried to avoid
baking anything into the standard api for this because I couldn't
really wrap my head around a sufficiently general, yet not too complicated
arrangement.

BTW, why did you ignore GCPs, and RPCs in your ShallowCopy() suggestion?

Best regards,

> /************************************************************************/
> /*                         ShallowCopy()                                */
> /************************************************************************/
> 
> GDALDataset *GDALDriver::ShallowCopy( const char * pszFilename,
>                                       GDALDataset * poSrcDS,
>                                       GDALDataType etype, int nBands,
>                                       int bStrict, char ** papszOptions,
>                                       GDALProgressFunc pfnProgress )
> 
> {
>     if( pfnProgress == NULL )
>         pfnProgress = GDALDummyProgress;
> 
> /* -------------------------------------------------------------------- */
> /*      Create destination dataset.                                     */
> /* -------------------------------------------------------------------- */
>     GDALDataset  *poDstDS;
>     int          nXSize = poSrcDS->GetRasterXSize();
>     int          nYSize = poSrcDS->GetRasterYSize();
>     CPLErr       eErr;
> 
>     CPLDebug( "GDAL", "Using default GDALDriver::CreateCopy implementation." );
> 
>     if( !pfnProgress( 0.0, NULL, pProgressData ) )
>     {
>         CPLError( CE_Failure, CPLE_UserInterrupt, "User terminated" );
>         return NULL;
>     }
> 
>     poDstDS = Create( pszFilename, nXSize, nYSize, nBands, eType,
> papszOptions );
> 
>     if( poDstDS == NULL )
>         return NULL;
> 
> /* -------------------------------------------------------------------- */
> /*      Try setting the projection and geotransform if it seems         */
> /*      suitable.  For now we don't try and copy GCPs, though I         */
> /*      suppose we should. Also copy metadata.                          */
> /* -------------------------------------------------------------------- */
>     double      adfGeoTransform[6];
> 
>     if( poSrcDS->GetGeoTransform( adfGeoTransform ) == CE_None
>         && (adfGeoTransform[0] != 0.0
>             || adfGeoTransform[1] != 1.0
>             || adfGeoTransform[2] != 0.0
>             || adfGeoTransform[3] != 0.0
>             || adfGeoTransform[4] != 0.0
>             || adfGeoTransform[5] != 1.0) )
>     {
>         poDstDS->SetGeoTransform( adfGeoTransform );
>     }
> 
>     if( poSrcDS->GetProjectionRef() != NULL
>         && strlen(poSrcDS->GetProjectionRef()) > 0 )
>     {
>         poDstDS->SetProjection( poSrcDS->GetProjectionRef() );
>     }
> 
>     poDstDS->SetMetadata( poSrcDS->GetMetadata() );
> 
>     return poDstDS;
> }


-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent