Application doesn't support direct import of GeoTIFF or GeoPDF at this moment, but these formats can be easily converted into *.mbtiles format that’s supported by Locus GIS. Since QGIS 3.8 this can be done directly, without any additional plugins, using the built-in Generate XYZ tiles (MBTiles) tool. Please see steps below:
Conversion to MBTILES
- Install QGIS SW
- Open your source GeoTIFF or GeoPDF file in QGIS (drag & drop the file into the map canvas, or use Layer > Add Layer > Add Raster Layer)
- Make sure all the layers you want to include in the map are enabled and arranged the way you want them to appear – the export captures the current map rendering
- Open the Processing Toolbox
- Menu > Processing > Toolbox (or click the gear icon, or press Ctrl+Alt+T)
- In the Processing Toolbox, expand Raster Tools and double-click Generate XYZ tiles (MBTiles)
- In the dialog, set the export parameters:
- Extent – the area to export. The easiest option is Use Layer Extent… and pick your source layer, or Use Canvas Extent
- Minimum zoom – how far out the map can be viewed (lower number = larger area visible)
- Maximum zoom – how far you can zoom in (higher number = more detail)
- Output file (for MBTiles) – choose Save to File… and enter the name and location of your *.mbtiles file
- The remaining parameters can be left at their default values.
- QGIS doesn’t automatically pick the ideal zoom levels based on the scale of your GeoTIFF/GeoPDF, so use the following maximum zoomsuggestions as a starting point:
- 1 : 50 000 – max zoom level about 15
- 1 : 25 000 – max zoom level about 16
- 1 : 10 000 – max zoom level 17
- 1 : 5 000 – max zoom level 18
- etc.
- Keep in mind that each additional zoom level roughly quadruples the file size and processing time, so a large area exported at a deep zoom level can produce a very large file.
- Click Run to generate the map. Depending on the extent and zoom range this may take a while.
Import to device
- Once you have the *.mbtiles file, import it directly in Locus GIS:
- Open Menu > Maps > tap the PLUS button > Import map
- A file picker opens, where you can browse to the *.mbtiles file from a number of sources, for example:
- System file manager – local device storage, e.g. the Download folder
- Dropbox
- OneDrive
- Select the *.mbtiles file to import it.
- The map is then available in Menu > Maps > Offline tab - select it to display.