[Qgis-user] QField

[Neumann, Andreas]

Hi Reginald, 

You can use the JPEG compression inside Geotiff. Note that this can be
specified separately for both the full resolution and the pyramids. You
can also select the compression factor to decrease the file size in
trade off with quality. 

See also http://www.gdal.org/frmt_gtiff.html and
http://www.gdal.org/gdaladdo.html for details. 

I believe that modern QGIS versions have these options exposed in the
GUI, but probably not as default. 

So maybe there is room for potential to get a smaller size Geotiff. 

Greetings,
Andreas 

On 2016-09-22 09:32, Reginald Carlier wrote:

> Thanks Andreas, 
> 
> Creating a Geotiff with pyramids did the trick. The only disadvantage is that it created a file of about 1.7 GB (the original was 90 MB). 
> 
> Now I am ready to test the app J. 
> 
> Regards, 
> 
> VAN: Neumann, Andreas [mailto:a.neumann at carto.net] 
> VERZONDEN: woensdag 21 september 2016 16:19
> AAN: Reginald Carlier
> ONDERWERP: Re: [Qgis-user] QField 
> 
> Hi Reginald, 
> 
> Did you create pyramids in the gpkg rasters? 
> 
> Generally, Geotiff should be well supported - definitely more tested than gpkg rasters. I had a 1GB geotiff on qfield (on SD-Card) and it displays fast. I haven't tested vrt files with geotiffs - if it works as well? 
> 
> Andreas 
> 
> On 2016-09-21 15:44, Reginald Carlier wrote:
> 
>> Hi Erwan, 
>> 
>> You can look in the list of last week where I posted a couple of questions about qfield and was pointed to the right website for documentation. 
>> 
>> I succeeded to publish a map on my phone but the aereal photo which was published as a gpkg file doesn't render. When I use the raster.gpkg on my desktop it renders but very slow. 
>> 
>> The gpkg file was created from a 90 MB jp2 file. 
>> 
>> Regards, 
>> 
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