[Proj] File Format Translation

[Hermann Peifer]

Kieran,

You can compress your GeoTIFF, see creation option COMPRESS=... on this 
page: http://www.gdal.org/frmt_gtiff.html

I usually do: -co compress=lzw

Hermann

PS:
I guess that this type of questions around GDAL tools is better sent to 
the gdal-dev mailing list.


On 17/08/2010 19:26, Ames, Kieran J. wrote:
> Hello list,
> I'd appreciate some guidance on translating MrSID files to geotiffs.
> Using gdal_translate, I can convert a MrSID file to geotiff. However,
> the resulting file size is on the order of 15 times larger (a 4MB .sid
> file becomes a 62MB .tif file).
> gdalinfo tells me that the files dimensions and other attributes are the
> same. However, I see the following differences that make me wonder if I
> can reduce file size.
> The .sid file:
> Band 1 Block=1024x128 Type=Byte, ColorInterp=Gray
> Minimum=59.000, Maximum=189.000, Mean=119.865, StdDev=17.205
> Overviews: 4000x4000, 2000x2000, 1000x1000, 500x500, 250x250, 125x125,
> 63x63,32x32
> the resulting .tif file after gdal_translate:
> Band 1 Block=8000x1 Type=Byte, ColorInterp=Gray
> Is there any information here that tells me about gdal_translate
> options/switches that may be available to me to make the .tif files smaller?
> I have .tif files from other geographies that support viewing reasonably
> clear information that are of sizes of about 150KB. I'm guessing that
> the MrSID files contain much more information than I'd need in order to
> reasonable present the data in a useful form.
> As background info (FWIW), the mrSID files are utilized in a SmallWorld
> app and we'd like to make this raster info available in other
> applications. We have no MrSID server in house and, with my limited
> knowledge, I am trying to make these rasters available to this new app
> as tiffs (since the other area's tiffs seem to work quite well) at no
> cost other than my time and my available disk space.
> Thanks for any suggestions.
> Kieran
>
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