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 _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
