[Gdal-dev] gtiff file size compared to original tiff +wrld file

[Simone Giannecchini]

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
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On Wed, Apr 22, 2009 at 10:49 AM, TJMartin <tjmgis at 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 at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>>
>>
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>>
>
> --
> 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.
>
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