Matt Hanneman wrote:
Can anyone tell me why the option 'STATISTICS=YES' works when using gdal_translate to translate from TIF to HFA (Erdas Imagine), but will NOT work when using gdal_merge to stack multiple TIFs into HFA? I need ArcMap to read the statistics, but it doesnt seem that they are being written to the file. I find this strange because ArcMap can identify the Stats when an HFA image is created with gdal_translate.
Matt, gdal_translate uses the HFA driver's "CreateCopy" method which honours the STATISTICS=YES creation option. gdal_merge uses the HFA driver's Create method and then imperatively writes chunks into the file here and there. The general write support does not honour the statistics option. Ideally the end user would not need to be too aware of the two creation strategies but in practice it is significant in a number of situations including yours, and the daily questions about why folks can't use gdal_merge.py to produce format XXX. If you need the statistics you will just have to produce a mosaic and then translate it again to produce a final file with the statistics. If the issue is very important to you it might be possible to modify things so that the statistics generated by gdalinfo -stats can be written back into the original HFA file in an ArcMap compatible form - but that could be pretty involved. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com 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 gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev