[Qgis-developer] Huge TIFF files - problem

Alex Mandel tech_dev at wildintellect.com
Mon Dec 8 23:43:06 PST 2014

On 12/08/2014 04:39 PM, Giovanni Manghi wrote:
>> Hi,
>> I have got a problem with TIFF files.
>> Today I was performing a rastercalculation ? two smaller files was suddenly 122 GB ? and my computer ran out of free space.
>> And this afternoon my students georeferenced a jpg, and ended up with 24 GB map.
>> What am I doing wrong?
> Hi Lene,
> I'm not sure if it is enough to justify such huge output files, but
> most of the tools in the "raster" menu just output always float64
> tiffs, that certainly contribute to make often bigger than the
> necessary. This has been fixed in Processing where most of the gdal
> tools now have an option to choose the type of geotiff for the output.
> cheers

That probably is the answer, not only float64 but no compression.
GeoTiff ideally would be a more appropriate storage based on the inputs
and calculation but also use Deflate or LZW compression. Seems to me a
reasonable default to use one of the lossless compression methods. Not
much to be done about the storage type though other than offer users
options when saving Tiffs where possible.


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