Tiling, merging

Raster mosaic

Let's create a virtual mosaic in VRT format using gdal raster mosaic

# run from the workshop data directory

$ gdal raster mosaic \
    --input-nodata 0 \
    SENTINEL2_L2A:S2B_MSIL2A_20260423T094029_N0512_R036_T34TDR_20260423T115714.SAFE/MTD_MSIL2A.xml:10m:EPSG_32634 \
    SENTINEL2_L2A:S2B_MSIL2A_20260423T094029_N0512_R036_T34TER_20260423T115714.SAFE/MTD_MSIL2A.xml:10m:EPSG_32634 \
    SENTINEL2_L2A:S2B_MSIL2A_20260423T094029_N0512_R036_T34TES_20260423T115714.SAFE/MTD_MSIL2A.xml:10m:EPSG_32634 \
    s2.vrt

Let's add overviews:

$ gdal raster overview add -r cubic s2.vrt

This generates a .vrt.ovr file

Let's open s2.vrt in QGIS

Raster tiling

Using gdal raster tile

$ gdal raster tile s2.vrt s2_tiled --format JPEG

ERROR 6: tile: Only up to 4 bands supported for JPEG (with alpha ignored).

Preliminary operations:

$ gdal raster select s2.vrt s2_rgb.vrt --band 1,2,3
$ gdal raster scale s2_rgb.vrt s2_rgb_clamped.vrt \
        --input-min 400 \
        --input-max 2400 \
        --output-data-type uint8

Now let's generate the individual files:

$ gdal raster tile s2_rgb_clamped.vrt s2_tiled --format JPEG

and check the result (if Firefox is not installed, manually open the file in the browser):

$ firefox s2_tiled/leaflet.html

Doing everything at the same time using a pipeline

Using gdal raster pipeline

$ gdal pipeline \
        mosaic SENTINEL2_L2A:S2B_MSIL2A_20260423T094029_N0512_R036_T34TDR_20260423T115714.SAFE/MTD_MSIL2A.xml:10m:EPSG_32634 \
        SENTINEL2_L2A:S2B_MSIL2A_20260423T094029_N0512_R036_T34TER_20260423T115714.SAFE/MTD_MSIL2A.xml:10m:EPSG_32634 \
        SENTINEL2_L2A:S2B_MSIL2A_20260423T094029_N0512_R036_T34TES_20260423T115714.SAFE/MTD_MSIL2A.xml:10m:EPSG_32634 \
        ! \
        select --band 1,2,3 \
        ! \
        scale --input-min 400 \
              --input-max 2400 \
              --output-data-type uint8 \
        ! \
        tile --min-zoom 10 s2_tiled_min_zoom10 --format WEBP

and check the result:

$ firefox s2_tiled_min_zoom10/openlayers.html

Exercise

Modify above pipeline to materialize the scaled dataset as a GeoTIFF before tiling.

(hint)

Hint

Use gdal raster materialize

==> Exercise solution for materializing pipeline intermediate result.

Vector partitioning

Using gdal vector partition

First let's create a GeoPackage file from the original OSM data with a slightly customized import configuration with the OSM tag amenity being exposed as a top-level GDAL attribute:

$ gdal vector convert timisoara.osm.pbf --layer points --oo CONFIG_FILE=osm_conf_amenity.ini amenity.gpkg

And let's create a partition around the values of that field:

$ gdal vector partition amenity.gpkg --field amenity amenity_partitioned

$ gdal vsi ls -lR amenity_partitioned

drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bar
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=bar/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=place_of_worship
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=place_of_worship/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=nightclub
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=nightclub/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=loading_dock
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=loading_dock/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=events_venue
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=events_venue/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=shelter
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=shelter/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=payment_terminal
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=payment_terminal/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=fast_food
-rw-r--r-- 1 unknown unknown       131072 2026-05-21 18:30 points/amenity=fast_food/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=veterinary
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=veterinary/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=childcare
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=childcare/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bus_station
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=bus_station/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=pharmacy
-rw-r--r-- 1 unknown unknown       139264 2026-05-21 18:30 points/amenity=pharmacy/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=casino
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=casino/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=smoking_area
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=smoking_area/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=recycling
-rw-r--r-- 1 unknown unknown       270336 2026-05-21 18:30 points/amenity=recycling/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=telephone
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=telephone/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=cinema
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=cinema/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=waste_transfer_station
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=waste_transfer_station/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=waste_basket
-rw-r--r-- 1 unknown unknown       126976 2026-05-21 18:30 points/amenity=waste_basket/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=ice_cream
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=ice_cream/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=university
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=university/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=conference_centre
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=conference_centre/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=dancing_school
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=dancing_school/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=vehicle_inspection
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=vehicle_inspection/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=parcel_locker
-rw-r--r-- 1 unknown unknown       135168 2026-05-21 18:30 points/amenity=parcel_locker/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=marketplace
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=marketplace/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=dentist
-rw-r--r-- 1 unknown unknown       110592 2026-05-21 18:30 points/amenity=dentist/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bank
-rw-r--r-- 1 unknown unknown       139264 2026-05-21 18:30 points/amenity=bank/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=clock
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=clock/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=gambling
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=gambling/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=studio
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=studio/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=post_box
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=post_box/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=kindergarten
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=kindergarten/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=charging_station
-rw-r--r-- 1 unknown unknown       110592 2026-05-21 18:30 points/amenity=charging_station/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=school
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=school/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=courthouse
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=courthouse/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=language_school
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=language_school/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=pub
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=pub/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=vending_machine
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=vending_machine/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=arts_centre
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=arts_centre/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=fuel
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=fuel/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=ferry_terminal
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=ferry_terminal/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=public_bookcase
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=public_bookcase/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=clinic
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=clinic/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=community_centre
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=community_centre/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=doctors
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=doctors/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=social_facility
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=social_facility/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=car_wash
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=car_wash/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=parking
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=parking/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=food_court
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=food_court/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bicycle_parking
-rw-r--r-- 1 unknown unknown       110592 2026-05-21 18:30 points/amenity=bicycle_parking/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=theatre
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=theatre/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=post_office
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=post_office/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=funeral_hall
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=funeral_hall/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=car_rental
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=car_rental/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=toilets
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=toilets/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=waste_disposal
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=waste_disposal/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=payment_centre
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=payment_centre/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bicycle_rental
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=bicycle_rental/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=fountain
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=fountain/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=atm
-rw-r--r-- 1 unknown unknown       114688 2026-05-21 18:30 points/amenity=atm/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=__HIVE_DEFAULT_PARTITION__
-rw-r--r-- 1 unknown unknown      3194880 2026-05-21 18:30 points/amenity=__HIVE_DEFAULT_PARTITION__/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=biergarten
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=biergarten/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=taxi
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=taxi/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=disused
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=disused/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bureau_de_change
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=bureau_de_change/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=veterinary_pharmacy
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=veterinary_pharmacy/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=townhall
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=townhall/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=library
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=library/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=drinking_water
-rw-r--r-- 1 unknown unknown       118784 2026-05-21 18:30 points/amenity=drinking_water/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=police
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=police/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=hospital
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=hospital/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bench
-rw-r--r-- 1 unknown unknown       180224 2026-05-21 18:30 points/amenity=bench/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=bicycle_repair_station
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=bicycle_repair_station/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=restaurant
-rw-r--r-- 1 unknown unknown       147456 2026-05-21 18:30 points/amenity=restaurant/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=driving_school
-rw-r--r-- 1 unknown unknown        98304 2026-05-21 18:30 points/amenity=driving_school/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=parking_entrance
-rw-r--r-- 1 unknown unknown       106496 2026-05-21 18:30 points/amenity=parking_entrance/part_0000000001.gpkg
drwxr-xr-x 1 unknown unknown         4096 2026-05-21 18:30 points/amenity=cafe
-rw-r--r-- 1 unknown unknown       126976 2026-05-21 18:30 points/amenity=cafe/part_0000000001.gpkg

Vector concatenation

Using gdal vector concat

--mode <MODE>                                              Determine the strategy to create output layers from source layers . MODE=merge-per-layer-name|stack|single (default: merge-per-layer-name)
--output-layer <OUTPUT-LAYER>                              Name of the output vector layer (single mode), or template to name the output vector layers (stack mode)
--source-layer-field-name <SOURCE-LAYER-FIELD-NAME>        Name of the new field to add to contain identification of the source layer, with value determined from 'source-layer-field-content'
--source-layer-field-content <SOURCE-LAYER-FIELD-CONTENT>  A string, possibly using {AUTO_NAME}, {DS_NAME}, {DS_BASENAME}, {DS_INDEX}, {LAYER_NAME}, {LAYER_INDEX}
--field-strategy <FIELD-STRATEGY>                          How to determine target fields from source fields. FIELD-STRATEGY=union|intersection (default: union)
-s, --input-crs <INPUT-CRS>                                Input CRS
-d, --output-crs <OUTPUT-CRS>                              Output CRS

Example:

$ gdal vector concat $(find amenity_partitioned -name "*.gpkg") concatenated.gpkg