Le lundi 14 septembre 2015 13:38:42, Stefan Ziegler a écrit : > Thanks Even. > > I was afraid that there will be no compression applied at all but this > behaviour is fine. > > The geotiff where I add the overviews is the result of a gdalwarp process > (tiled, deflate, preditor=2). When I gdal_translate this geotiff with the > very same compression parameters I gain approx. 10 percent space. Sounds > this comprehensible? (I'm pretty sure there was once some discussion on the > mailing list but couldn't find anything).
Yes, see https://trac.osgeo.org/gdal/wiki/UserDocs/GdalWarp#GeoTIFFoutput-coCOMPRESSisbroken > > regards > Stefan > > On Mon, Sep 14, 2015 at 11:56 AM, Even Rouault <[email protected]> > > wrote: > > Le lundi 14 septembre 2015 11:46:45, Stefan Ziegler a écrit : > > > Hi > > > > > > we are facing problems with the compression of the overviews we are > > > > adding > > > > > with gdaladdo. The filesize does not differ whether we are using > > > compression parameters or not. The filesize of the input raster is > > > > approx. > > > > > 100 mb. The following both commands resulting in an identical filesize > > > of approx. 140mb. > > > > > > gdaladdo -r average 591252_12_5cm.tif 2 4 8 16 32 > > > > > > gdaladdo -r average --config COMPRESS_OVERVIEW JPEG --config > > > PHOTOMETRIC_OVERVIEW YCBCR --config INTERLEAVE_OVERVIEW PIXEL > > > 591252_12_5cm.tif 2 4 8 16 32 > > > > Stefan, > > > > The config options are only used for external overviews (-ro flag). For > > internal > > overviews, the same compression scheme as the full resolution image is > > used. > > In theory they could also use a different compression scheme, but this > > isn't > > currently implemented. > > > > Even > > > > > The input raster is tiled and compressed with deflate (and predictor=2) > > > > > > I would expect that the latter one would be smaller. Did we > > > misunderstand something? Or do we use the parameters the wrong way? > > > > > > GDAL 1.11.2 and dev. > > > > > > regards > > > Stefan > > > > -- > > Spatialys - Geospatial professional services > > http://www.spatialys.com -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
