AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2008.09.23 16:24 "[Tiff] New to list, with a query on TIFFTAG_GDAL_METADATA", by David J Taylor
2008.09.23 16:57 "Re: [Tiff] New to list, with a query on TIFFTAG_GDAL_METADATA", by Frank Warmerdam
2008.09.24 08:18 "Re: [Tiff] New to list, with a query on TIFFTAG_GDAL_METADATA", by David J Taylor
2008.09.24 08:44 "Re: [Tiff] New to list, with a query on TIFFTAG_GDAL_METADATA", by David J Taylor
2008.10.22 23:31 "Re: [Tiff] JPEGSetupEncode messages", by Raphaël_Lemoine
2008.10.22 21:12 "[Tiff] JPEGSetupEncode messages", by Jeffrey Ratcliffe
2008.10.22 23:16 "Re: [Tiff] JPEGSetupEncode messages", by Frank Warmerdam
2008.10.23 13:44 "Re: [Tiff] JPEGSetupEncode messages", by Bob Friesenhahn
2008.10.23 00:08 "Re: [Tiff] JPEGSetupEncode messages", by Frank Warmerdam
2008.10.23 10:56 "Re: [Tiff] JPEGSetupEncode messages", by Gerben Vos
2008.10.23 19:56 "Re: [Tiff] JPEGSetupEncode messages", by Jeffrey Ratcliffe
2008.10.23 20:12 "Re: [Tiff] JPEGSetupEncode messages", by Bob Friesenhahn

2008.09.23 16:57 "Re: [Tiff] New to list, with a query on TIFFTAG_GDAL_METADATA", by Frank Warmerdam

I'm new to this list, so please forgive any netiquette errors!

I have a GeoTIFF application working with FWTools V1.3.7 DLLs, and using Delphi as my language. I now need to write some GDAL data, so I woudl like to do something like this:

  TIFFSetField (tif, TIFFTAG_GDAL_METADATA, PChar (txt));

However, the field is unrecognised, and trying to define a new TIFF field using

TIFFMergeFieldInfo seems to be complicated and indeed to be deprecated. How should I be doing this?

David,

GDAL uses this code to merge in the TIFFTAG_GDAL_METADATA tag.

static void GTiffTagExtender(TIFF *tif)

{
     static const TIFFFieldInfo xtiffFieldInfo[] = {

         { TIFFTAG_GDAL_METADATA,    -1,-1, TIFF_ASCII, FIELD_CUSTOM,
           TRUE,        FALSE,  (char*) "GDALMetadata" },
         { TIFFTAG_GDAL_NODATA,     -1,-1, TIFF_ASCII,  FIELD_CUSTOM,
           TRUE,        FALSE,  (char*) "GDALNoDataValue" },
         { TIFFTAG_RPCCOEFFICIENT,   -1,-1, TIFF_DOUBLE,        FIELD_CUSTOM,
           TRUE,        TRUE,   (char*) "RPCCoefficient" }

     };

     if (_ParentExtender)
         (*_ParentExtender)(tif);

     TIFFMergeFieldInfo( tif, xtiffFieldInfo,
                        sizeof(xtiffFieldInfo) / sizeof(xtiffFieldInfo[0]) );
}

I'm not at all sure how this might be accomplished from Delphi Pascal.

Libtiff should automatically prepare a definition for the tag if it is encountered in an existing file, but I don't know how you would add such a tag to a new file without defining it.

I'm not aware of a newer cleaner way of doing the same thing.

Best regards,
--
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