[Qgis-user] QField

[Matthias Kuhn]

QField does not (yet) support tiff with jpeg compression.

See:
http://www.qfield.org/docs/project-management/dataformat.html#raster-data

GeoPackage worked quite nice in our experience and can also be built in different resolutions (same page further down).

Matthias


On 09/22/2016 09:37 AM, Neumann, Andreas wrote:
> 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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> >
> >  
> >
>  
>
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