Christian and others just to post an update that others might find useful.
Using the shell command line i used For %I in C:\Data\250k\*.tif do gdal_translate –of gtiff –co “COMPRESS=LZW” %I C:\Data\250k\geotiffs\%~nI.tif this ran through the entire folder translating my tiff_world files in LZW compression to geotiffs with LZW compression. it worked v well and got the same output size as the inputs (as you woudl expect) then because of the file sizes i used gdalwarp rather than gdal_merge.py (as i seen other posts where people had issues with large rasters) i originally ran just using Gdalwarp C:\Data\250k\geotiffs\*.tif C:\Data\250k\geotiffs\merge.tif and it took 5hrs and 40mins to process and gave me a merged ratser of 1.5gb - i noticed my error, i forgot to add the COMPRESS option so ran it again using the compression to LZW, this took 3hrs for the 56 files and resulted in a 675mb file. this i felt was still much larger than the original files. i used gdalinfo to check it was compressed, and the info said it was so for the fun of it i ran a quick gdal_translate C:\...\merge.tif C:\......\mosaic.tif -co "COMPRESS=YES" and the results was a 147mb mosaic. so i am not sure what the code is behind the gdalwarp compared to the gdal_translate but would have thought they should compress the same. if anyone knows why i get this difference would be great to know as it would remove an extra step from the batch file. Simone - i posted here rather than over at Geoserver because it was the gdal that i couldnt seem to get working rather than the method of loading to geoserver. Simone Giannecchini-2 wrote: > > Ciao Tim, > you should probably post these questions to the geoserver users mailing > list. > > Simone. > ------------------------------------------------------- > Ing. Simone Giannecchini > GeoSolutions S.A.S. > Owner - Software Engineer > Via Carignoni 51 > 55041 Camaiore (LU) > Italy > > phone: +39 0584983027 > fax: +39 0584983027 > mob: +39 333 8128928 > > > http://www.geo-solutions.it > http://simboss.blogspot.com/ > http://www.linkedin.com/in/simonegiannecchini > > ------------------------------------------------------- > > > > On Wed, Apr 22, 2009 at 10:49 AM, TJMartin <tjm...@gmail.com> wrote: >> >> Hi christian >> >> many thanks for your help, i will run this later on today/overnight :) >> >> I saw that Geoserver tutorail using the database to store the files but >> think i will stick with using just files. >> >> will postback later on if and when i get it all running >> >> thanks again >> >> Tim >> >> >> >> Christian Müller wrote: >>> >>> Hi, I did this process last year many times and here is my experience >>> >>> 1) I assume you omitted the create options, your original tiff files are >>> compressed, the new ones not. >>> Look here http://www.gdal.org/frmt_gtiff.html, on the commandline it is >>> -co >>> "COMPRESS=JPEG" as an example. >>> >>> 2) Take a look at your tiles with gdalinfo, do the have a color table or >>> more bands ?. If your tiles have >>> more bands, (e. g. one for read, one for green and one for blue), use >>> gdal_merge.py with -pct to produce a big picture >>> having only one band and a color table. Create your tiles from the big >>> picture. Geoserver will say thank you in terms >>> of memory usage and cpu performance. >>> >>> 3) Decide, wich Geoserver module to use. There are 2 of them. There is a >>> file based approach and a jdbc based >>> approach (Module imagemosic-jdbc). If you want to store the whole stuff >>> in >>> a >>> database, use gdal_retile.py to procude your >>> tiles and pyramids and the imagemosic-jdbc module to import all the >>> tiles. >>> Both, gdal_retily.py and the imagemosaic-jdbc >>> module were developed by me, if you have questions, ask. >>> >>> The documentation is here >>> http://docs.codehaus.org/display/GEOTDOC/Image+Mosaicing+Pyramidal+JDBC+Plug >>> in >>> A tutorial for geoserver is here >>> http://geoserver.org/display/GEOSDOC/Using+the+ImageMosaic+JDBC+Plugin >>> >>> christian >>> >>> >>> TJMartin writes: >>> >>>> >>>> Hi All >>>> >>>> I am just getting started with gdal, and i have done a search but >>>> couldnt >>>> find an answer. >>>> >>>> I currently have 10,000 tiff files with their world files. My real aim >>>> is >>>> to >>>> tile them up and make them easier to use in Geoserver or create an >>>> image >>>> pyramid. >>>> >>>> So i used gdal_translate to Geotiff, then was going to use gdalwarp to >>>> mosaic, then tile them. >>>> >>>> However the file size for geotiffs are between 4 and 15 times the size >>>> >>>> 4mb to 60mb >>>> >>>> One set were originally 128mb and now 858mb. >>>> >>>> So if i was to mosiac these and then tile them it will still be a huge >>>> data/size volume to server via geoserver. >>>> >>>> >>>> So my questions >>>> >>>> 1) Can i reduce the quality when translating to geotiff, and how much >>>> will >>>> this affect the image quality when i mosaic and tile >>>> >>>> 2) Should i mosaic the tiff + world files instead and then tile them >>>> with >>>> world files instead of using geotiffs >>>> >>>> 3) is there a better way of doing this? >>>> >>>> would really appreciate anyone's help >>>> >>>> all the best >>>> >>>> Tim >>>> >>>> -- >>>> View this message in context: >>>> http://n2.nabble.com/gtiff-file-size-compared-to-original-tiff-%2Bwrld-file-tp2672921p2672921.html >>>> Sent from the GDAL - Dev mailing list archive at Nabble.com. >>>> >>>> _______________________________________________ >>>> gdal-dev mailing list >>>> gdal-dev@lists.osgeo.org >>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev >>> >>> >>> _______________________________________________ >>> gdal-dev mailing list >>> gdal-dev@lists.osgeo.org >>> http://lists.osgeo.org/mailman/listinfo/gdal-dev >>> >>> >> >> -- >> View this message in context: >> http://n2.nabble.com/gtiff-file-size-compared-to-original-tiff-%2Bwrld-file-tp2672921p2674970.html >> Sent from the GDAL - Dev mailing list archive at Nabble.com. >> >> _______________________________________________ >> gdal-dev mailing list >> gdal-dev@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/gdal-dev >> > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev > > -- View this message in context: http://n2.nabble.com/gtiff-file-size-compared-to-original-tiff-%2Bwrld-file-tp2672921p2686259.html Sent from the GDAL - Dev mailing list archive at Nabble.com. _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
