<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt">Jukka,<br><br>Thank you very much for your reply and tips. I have already gone over the GeoServer on Steroids, which is a very good and informative document. <br><br>Best regards,<br>Ammar<br><div><span><br></span></div><div><br></div> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font face="Arial" size="2"> <b><span style="font-weight:bold;">From:</span></b> Jukka Rahkonen <jukka.rahkonen@mmmtike.fi><br> <b><span style="font-weight: bold;">To:</span></b> gdal-dev@lists.osgeo.org <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, December 5, 2013
6:58 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [gdal-dev] Tiling and Overviews disappear after compressing with LZW<br> </font> </div> <div class="y_msg_container"><br>Ammar <ammar83_h <at> yahoo.com> writes:<br><br>> <br>> Hello list,<br><br>> <br>> I am new to GDAL and I have been using the utilities to process and<br>prepare TIFF to create a mosaic in Geoserver. I am<br>> expermineting with different<br>> compression methods and I have noticed that after compressing a file with<br>LZW, the previously created tiles and overviews disappear!<br><br>Hi,<br><br>Experimenting is good but reading manuals is not a bad idea either. I<br>recommend these Geoserver recipes<br><a href="http://www.slideshare.net/geosolutions/gs-steroids-sgiannecfoss4g20130103" target="_blank">http://www.slideshare.net/geosolutions/gs-steroids-sgiannecfoss4g20130103</a><br><br>The gdaladdo manual page <a
href="http://www.gdal.org/gdaladdo.html" target="_blank">http://www.gdal.org/gdaladdo.html </a>seems to need<br>some improvements but is is still worth reading.<br><br>Gdal_translate writes always a new file, it does not improve something<br>existing. Gdaladdo behaves a bit differently and it add overviews into<br>existing geotiff.<br><br>Good defaults for aerial images is to run first<br><br>gdal_translate -of GTiff -co tiled=yes -co compress=jpeg -co<br>PHOTOMETRIC=YCBCR in.tif out.tif<br><br>and then <br>gdaladdo --config COMPRESS_OVERVIEW JPEG --config PHOTOMETRIC_OVERVIEW YCBCR<br> --config INTERLEAVE_OVERVIEW PIXEL out.tif 2 4 8 16<br><br>For raster maps jpeg compression is not ideal. Experiment with compression<br>methods (or stay with uncompressed if you have space), resampling options<br>and consider if you want to use internal or external overviews (-ro). Both<br>behave in a similar way but building internal
overviews saves some disk<br>space. On the other hand external overviews can be removed easily if you<br>want to have a try with different parameters. <br><br>-Jukka Rahkonen-<br><br>_______________________________________________<br>gdal-dev mailing list<br><a ymailto="mailto:gdal-dev@lists.osgeo.org" href="mailto:gdal-dev@lists.osgeo.org">gdal-dev@lists.osgeo.org</a><br><a href="http://lists.osgeo.org/mailman/listinfo/gdal-dev" target="_blank">http://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br><br></div> </div> </div> </div></body></html>