Formatele de Date Acceptate¶
QField acceptă o mare varietate de formate prin intermediul furnizorilor de date QGIS și GDAL. Această pagină oferă o listă neexhaustivă a formatelor de date acceptate.
| Formatul Datelor | Acceptat | Observații |
|---|---|---|
| Spatialite | ||
| Geopackage | ||
| WMS | ||
| WFS | ||
| WFS-T | ||
| Postgis | ||
| MBTiles | ||
| Fișier shape | ||
| Tiff | ||
| JPEG2000 | ||
| WEBP | ||
| ECW | Licența restricționează utilizarea. | |
| MrSID | Licența restricționează utilizarea. |
If you don't find your favorite data format on this table, please check if it works and adapt the list above to share your findings. If it does not work, please open an issue. We will be happy to help you with the implementation.
Date raster¶
Raster data can become quite big quickly, when working with uncompressed tiff files it's often several Gb of data. Especially on mobile devices, this is inefficient.
Use COG (Cloud Optimized GeoTIFF)¶
The Cloud Optimized Geotiff (COG) format will offer best user experience for offline basemaps. Combined with JPEG compression, it will reduce the raster size.
The following commands will convert a file called raster.tif to a COG file raster_cog.tif using JPEG compression.
gdal_translate raster.tif raster_cog.tif -of COG -co BLOCKSIZE=512 -co COMPRESS=JPEG -co QUALITY=75 -co BIGTIFF=YES
Advanced examples with COG¶
If you have several files to assemble, first, you need to create a VRT files with QGIS or trough following commands to index all TIF files inside a directory. Make sure you adjust EPSG:2056 to your desired CRS.
gdalbuildvrt raster_mosaic.vrt TIF_Directory/*.tif -addalpha -hidenodata -a_srs EPSG:2056
Then convert VRT file to COG.
gdal_translate raster_mosaic.vrt raster_cog.tif -of COG -co BLOCKSIZE=512 -co COMPRESS=JPEG -co QUALITY=75 -co BIGTIFF=YES
If the raster data is too low quality, adjust the compression level and set QUALITY=85.
Some extra parameters can be set :
a_srscan be used also in gdal_translate command when CRS is not define in the source raster dataset.OVERVIEW_RESAMPLINGoffer different renderer when zooming out. The default value is NEAREST but you can try also BILINEAR or AVERAGE.NUM_THREADSwill help you to balance between use all your CPU resources or only part. Set ALL_CPUS or define the number of thread you want to use.
Combining all extra parameters, command line may look like this :
gdal_translate raster.tif raster_cog.tif -a_srs EPSG:2056 -of COG -co BLOCKSIZE=512 -co OVERVIEW_RESAMPLING=BILINEAR -co COMPRESS=JPEG -co QUALITY=75 -co NUM_THREADS=6 -co BIGTIFF=YES