File Formats

openEO Platform offers different file formats for importing and exporting of data.

Best practices file formats

Depending on the data cube that your process graph creates and on your later use case, some file formats are more suitable to export your data (save_result) in than others. Following a brief overview of the most common use cases.

Raster Formats

• JPEG/PNG: data formats that are well suited for use in media/printing
  • not georeferenced (therefore only of limited use for further analysis)
  • limited to 3 (JPEG) or 4 (PNG) output bands (image channels)
  • usually contains data from 1 timestamp
• netCDF: ideal for time series data as it stores data in multi-dimensional arrays
  • georeferenced (x/y dimensions)
  • can store multiple bands (band dimension)
  • can store multiple timestamps (time dimension)
  • self-describing, portable and scalable
• GeoTiff: ideal for storing several bands in one file in cloud optimized format
  • georeferenced
  • can store multiple bands
  • a single GeoTiff corresponds to one timestamp (in combination with STAC, multi-temporal collections can be supported)
  • cloud optimized

Federation agreement file formats

If back-ends offer/mirror the same file formats for both import and export, it is required to align them.

For file export through save_result for example, the output parameters and the structure of the data that is written to storage needs to be defined. For the following file formats an agreement has been achieved:

• GeoTiff
• netCDF

The idea of these guidelines is to align with what the formats and corresponding toolchains support as much as possible.

GeoTiff

Defaults:

• a single GeoTiff corresponds to one timestamp (in combination with STAC, multi-temporal collections can be supported)
• All datacube bands are stored in the same geotiff
• The full spatial extent is written to the same geotiff
• Cloud optimized
• For ideal support in the Web Editor (and other tools), the following guide is recommended to be followed: https://github.com/Open-EO/openeo-web-editor/blob/master/docs/geotiff.md (opens new window)

netCDF

Defaults:

• The full datacube is written to a single netCDF.
• The openEO dimension metadata is preserved in the netCDF file.
• CF conventions (https://cfconventions.org/) are used where applicable.
• Data is chunked and compressed

More information on all supported file formats, can be found here.