Christoph, gdaladdo always start from the full resolution layer (or the preceding overview in case of cascading overview), hence what you observe. And even if it did start from the nearest existing overview level, in your full scenario of a VRT of VRT, with each 'bottom-level' VRT having overviews, that wouldn't ause the overall VRT to be able to expose overview bands.
That said, there's a trick you can use If you do: gdal_translate second_level.vrt tmp.tif -outsize 3.125% 3.125% -of GTiff mv tmp.tif second_level.vrt.ovr you'll get a 1/32 overview, and this will be able to use the overviews of the bottom-level VRTs and you can then run gdaladdo on second_level.vrt.ovr Regarding the fact the gdalinfo first_level.vrt only reports overviews of size 500x500, 250x250, this is because of an optimization of the VRT driver that do not report overviews smaller than 128x128. Even -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
