[Qgis-developer] RasterFileWriter creates 5 times bigger geotiff then gdal_translate

G. Allegri giohappy at gmail.com
Sat Jul 5 11:17:35 PDT 2014


Sorry for the buzz. It's not QGIS fault, it's GDAL itself which reads the
ASCII Grid as Float64, but I wonder why contrarily gdalinfo and
gdal_translate treats it as Float32...


2014-07-05 18:56 GMT+02:00 G. Allegri <giohappy at gmail.com>:

> I haven't spot tha exact point where this happens but QGIS exports
> Float64, even if the origin was Float32.
>
> giovanni
>
>
> 2014-07-05 16:54 GMT+02:00 G. Allegri <giohappy at gmail.com>:
>
> Causally I hit the save as raster dialog, and I tried to export a raster
>> to layer (coming from an ASCII Grid source) to Geotiff, with no creation
>> options set.
>> The result was a file 3 times bigger then the original ASCII, and 5 times
>> bigger then the Geotiff created by gdal_translate.
>>
>> gdalinfo on the files give same results (except statistics missing from
>> the one created by RasterFileWriter).
>> Does gdal_translate do some optimizations that RFW doesn't?
>> I wasn't aware that two Geotiffs, apparently with the same properties,
>> could be so different in size...
>>
>> giovanni
>>
>> --
>> Giovanni Allegri
>> http://about.me/giovanniallegri
>> Twitter: https://twitter.com/_giohappy_
>> blog: http://blog.spaziogis.it
>> GEO+ geomatica in Italia http://bit.ly/GEOplus
>>
>
>
>
> --
> Giovanni Allegri
> http://about.me/giovanniallegri
> Twitter: https://twitter.com/_giohappy_
> blog: http://blog.spaziogis.it
> GEO+ geomatica in Italia http://bit.ly/GEOplus
>



-- 
Giovanni Allegri
http://about.me/giovanniallegri
Twitter: https://twitter.com/_giohappy_
blog: http://blog.spaziogis.it
GEO+ geomatica in Italia http://bit.ly/GEOplus
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