[Qgis-user] QField: recommendations for aerial basemap preparation?

[Bernd Vogelgesang]

Hi,

I need an aerial basemap for my QField-project to be able to locate
positions. As QField has not the ability to navigate to a point or
indicate the direction of movement, provided only with a topographic
basemap, I'm stumbling through the forest and have a hard time finding
the positions.

The project area is huge, around 400 square kilometers! I have a Mrsid
file of the area of 1.6 GB with 20 centimeter resolution,
transformed with gdal_translate to tiff is 42.5 GB,
compressed with gdal_transform with jped-compression 50% 968 MB,
resampled to 40cm resolution and 50% jpeg has 295 MB

I used the QField sync plugin to generate a baselayer in gpgk-format
from this ,which has 540 MB with 40 cm resolution.

Unfortunately, on the tablet, the baselayer is loading so slow, that it
is impossible to work with it. Each redraw takes around 10 seconds in
the small scale, rising to infinity in higher scales.

I wonder if there are other approaches recommendable, for example
splitting the image into separate layers for bigger regions, which I
could then turn on and off, or if I should prepare the image apart from
using the plugins converter to gpkg.

Due to the enourmous amount of time needed to process the image on the
PC, a trial-and-error approach seems not to be feasable, so I ask you if
someone can recommend an approach for such a huge beast.


Thanx in advance,

Bernd