# gdal2tiles.py

Generates directory with TMS tiles, KMLs and simple web viewers.

## Synopsis

    gdal2tiles.py [-p profile] [-r resampling] [-s srs] [-z zoom]
                  [-e] [-a nodata] [-v] [-q] [-h] [-k] [-n] [-u url]
                  [-w webviewer] [-t title] [-c copyright]
                  [--processes=NB_PROCESSES] [--mpi] [--xyz]
                  [--tilesize=PIXELS] [--tmscompatible]
                  [-g googlekey] [-b bingkey] input_file [output_dir] [COMMON_OPTIONS]

## Description

This utility generates a directory with small tiles and metadata, following the OSGeo Tile Map Service Specification. Simple web pages with viewers based on Google Maps, OpenLayers and Leaflet are generated as well - so anybody can comfortably explore your maps on-line and you do not need to install or configure any special software (like MapServer) and the map displays very fast in the web browser. You only need to upload the generated directory onto a web server.

GDAL2Tiles also creates the necessary metadata for Google Earth (KML SuperOverlay), in case the supplied map uses EPSG:4326 projection.

World files and embedded georeferencing is used during tile generation, but you can publish a picture without proper georeferencing too.

Note

Inputs with non-Byte data type (i.e. `Int16`, `UInt16`,…) will be clamped to the `Byte` data type, causing wrong results. To avoid this it is necessary to rescale input to the `Byte` data type using gdal_translate utility.

Note

Config options of the input drivers may have an effect on the output of gdal2tiles. An example driver config option is GDAL_PDF_DPI, which can be found at Configuration options

-p <PROFILE>, --profile=<PROFILE>

  Tile cutting profile (mercator, geodetic, raster) - default ‘mercator’ (Google Maps compatible).

  Starting with GDAL 3.2, additional profiles are available from tms_XXXX.json files placed in GDAL data directory (provided all zoom levels use same origin, tile dimensions, and resolution between consecutive zoom levels vary by a factor of two).

-r <RESAMPLING>, --resampling=<RESAMPLING>

  Resampling method (average, near, bilinear, cubic, cubicspline, lanczos, antialias, mode, max, min, med, q1, q3) - default ‘average’.

-s <SRS>, --s_srs=<SRS>

  The spatial reference system used for the source input data.

--xyz

  Generate XYZ tiles (OSM Slippy Map standard) instead of TMS. In the default mode (TMS), tiles at y=0 are the southern-most tiles, whereas in XYZ mode (used by OGC WMTS too), tiles at y=0 are the northern-most tiles.

  New in version 3.1.

-d, --tmscompatible

  When using the geodetic profile, specifies the base resolution as 0.703125 or 2 tiles at zoom level 0.

-z <ZOOM>, --zoom=<ZOOM>

  Zoom levels to render (format:’2-5’, ‘10-’ or ‘10’).

-e, --resume

  Resume mode. Generate only missing files.

-a <NODATA>, --srcnodata=<NODATA>

  Value in the input dataset considered as transparent. If the input dataset had already an associate nodata value, it is overridden by the specified value.

-v, --verbose

  Generate verbose output of tile generation.

  Starting with GDAL 3.7, that verbose output is emitted through the `logging.getLogger("gdal2tiles")` object.

-x, --exclude

  Exclude transparent tiles from result tileset.

-q, --quiet

  Disable messages and status to stdout

  New in version 2.1.

--processes=<NB_PROCESSES>

  Number of parallel processes to use for tiling, to speed-up the computation.

  New in version 2.3.

--mpi

  Assume launched by mpiexec, enable MPI parallelism and ignore –processes. Requires working MPI environment and the MPI for Python (mpi4py) package. User should set GDAL_CACHEMAX to an appropriate cache size per process based on memory per node and the number of processes launched per node.

  New in version 3.5.

--tilesize=<PIXELS>

  Width and height in pixel of a tile. Default is 256.

  New in version 3.1.

--tiledriver=<DRIVER>

  Which output driver to use for the tiles, determines the file format of the tiles. Currently PNG and WEBP are supported. Default is PNG. Additional configuration for the WEBP driver are documented below.

  New in version 3.6.

-h, --help

  Show help message and exit.

--version

  Show program’s version number and exit.

### KML (Google Earth) options

Options for generated Google Earth SuperOverlay metadata

-k, --force-kml

  Generate KML for Google Earth - default for ‘geodetic’ profile and ‘raster’ in EPSG:4326. For a dataset with different projection use with caution!

-n, --no-kml

  Avoid automatic generation of KML files for EPSG:4326.

-u <URL>, --url=<URL>

  URL address where the generated tiles are going to be published.

### Web viewer options

Options for generated HTML viewers a la Google Maps

-w <WEBVIEWER>, --webviewer=<WEBVIEWER>

  Web viewer to generate (all, google, openlayers, leaflet, mapml, none) - default ‘all’.

-t <TITLE>, --title=<TITLE>

  Title of the map.

-c <COPYRIGHT>, --copyright=<COPYRIGHT>

  Copyright for the map.

-g <GOOGLEKEY>, --googlekey=<GOOGLEKEY>

  Google Maps API key from http://code.google.com/apis/maps/signup.html.

-b <BINGKEY>, --bingkey=<BINGKEY>

  Bing Maps API key from https://www.bingmapsportal.com/

Note

gdal2tiles.py is a Python script that needs to be run against Python GDAL binding.

### MapML options

MapML support is new to GDAL 3.2. When –webviewer=mapml is specified, –xyz is implied, as well as –tmscompatible if –profile=geodetic.

The following profiles are supported:

- mercator: mapped to OSMTILE MapML tiling scheme

- geodetic: mapped to WGS84 MapML tiling scheme

- APSTILE: from the tms_MapML_APSTILE.json data file

The generated MapML file in the output directory is `mapml.mapl`

Available options are:

--mapml-template=<filename>

  Filename of a template mapml file where variables will be substituted. If not specified, the generic template_tiles.mapml file from GDAL data resources will be used

The –url option is also used to substitute `${URL}` in the template MapML file.

### WEBP options

WEBP tiledriver support is new to GDAL 3.6. It is enabled by using –tiledriver=WEBP.

The following configuration options are available to further customize the webp output:

--webp-quality=<QUALITY>

  QUALITY is a integer between 1-100. Default is 75.

--webp-lossless

  Use WEBP lossless compression, default is lossy

Note

GDAL WEBP driver documentation can be consulted

## Examples

Basic example:

    gdal2tiles.py --zoom=2-5 input.tif output_folder

MapML generation:

    gdal2tiles.py --zoom=16-18 -w mapml -p APSTILE --url "https://example.com" input.tif output_folder

MPI example:

    mpiexec -n $NB_PROCESSES gdal2tiles.py --mpi --config GDAL_CACHEMAX 500 --zoom=2-5 input.tif output_folder