Ammar <ammar83_h <at> yahoo.com> writes: > > Hello list,
> > I am new to GDAL and I have been using the utilities to process and prepare TIFFÂ to create a mosaic in Geoserver. I am > expermineting with different > compression methods and I have noticed that after compressing a file with LZW, the previously created tiles and overviews disappear! Hi, Experimenting is good but reading manuals is not a bad idea either. I recommend these Geoserver recipes http://www.slideshare.net/geosolutions/gs-steroids-sgiannecfoss4g20130103 The gdaladdo manual page http://www.gdal.org/gdaladdo.html seems to need some improvements but is is still worth reading. Gdal_translate writes always a new file, it does not improve something existing. Gdaladdo behaves a bit differently and it add overviews into existing geotiff. Good defaults for aerial images is to run first gdal_translate -of GTiff -co tiled=yes -co compress=jpeg -co PHOTOMETRIC=YCBCR in.tif out.tif and then gdaladdo --config COMPRESS_OVERVIEW JPEG --config PHOTOMETRIC_OVERVIEW YCBCR --config INTERLEAVE_OVERVIEW PIXEL out.tif 2 4 8 16 For raster maps jpeg compression is not ideal. Experiment with compression methods (or stay with uncompressed if you have space), resampling options and consider if you want to use internal or external overviews (-ro). Both behave in a similar way but building internal overviews saves some disk space. On the other hand external overviews can be removed easily if you want to have a try with different parameters. -Jukka Rahkonen- _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
