geobuf

Geobuf

Geobuf is a compact binary geospatial format for lossless compression of GeoJSON and TopoJSON data.

|Build Status| |Coverage Status|

Note well: this project is no longer actively developed. Issues and pull requests will be attended to when possible, but delays should be expected.

Advantages over using GeoJSON and TopoJSON directly (in this revised version <https://github.com/mapbox/geobuf/issues/27>__):

• Very compact: typically makes GeoJSON 6-8 times smaller and TopoJSON 2-3 times smaller.
• Smaller even when comparing gzipped sizes: 2-2.5x compression for GeoJSON and 20-30% for TopoJSON.
• Easy incremental parsing — you can get features out as you read them, without the need to build in-memory representation of the whole data.
• Partial reads — you can read only the parts you actually need, skipping the rest.
• Trivial concatenation: you can concatenate many Geobuf files together and they will form a valid combined Geobuf file.
• Potentially faster encoding/decoding compared to native JSON implementations (i.e. in Web browsers).
• Can still accommodate any GeoJSON and TopoJSON data, including extensions with arbitrary properties.

Think of this as an attempt to design a simple, modern Shapefile successor that works seamlessly with GeoJSON and TopoJSON.

Unlike Mapbox Vector Tiles <https://github.com/mapbox/vector-tile-spec/>__, it aims for lossless compression of datasets — without tiling, projecting coordinates, flattening geometries or stripping properties.

pygeobuf ^^^^^^^^

This repository is the first encoding/decoding implementation of this new major version of Geobuf <https://github.com/mapbox/geobuf>__ (in Python). It serves as a prototyping playground, with faster implementations in JS and C++ coming in future.

Sample compression sizes ^^^^^^^^^^^^^^^^^^^^^^^^

::

                | normal    | gzipped

+---------------------+-------------+------------+ | us-zips.json | 101.85 MB | 26.67 MB | +---------------------+-------------+------------+ | us-zips.pbf | 12.24 MB | 10.48 MB | +---------------------+-------------+------------+ | us-zips.topo.json | 15.02 MB | 3.19 MB | +---------------------+-------------+------------+ | us-zips.topo.pbf | 4.85 MB | 2.72 MB | +---------------------+-------------+------------+ | idaho.json | 10.92 MB | 2.57 MB | +---------------------+-------------+------------+ | idaho.pbf | 1.37 MB | 1.17 MB | +---------------------+-------------+------------+ | idaho.topo.json | 1.9 MB | 612 KB | +---------------------+-------------+------------+ | idaho.topo.pbf | 567 KB | 479 KB | +---------------------+-------------+------------+

Usage

Command line:

.. code:: bash

    geobuf encode < example.json > example.pbf
    geobuf decode < example.pbf > example.pbf.json

As a module:

.. code:: python

    import geobuf

    pbf = geobuf.encode(my_json) # GeoJSON or TopoJSON -> Geobuf string
    my_json = geobuf.decode(pbf) # Geobuf string -> GeoJSON or TopoJSON

The ``encode`` function accepts a dict-like object, for example the
result of ``json.loads(json_str)``.

Both ``encode.py`` and ``geobuf.encode`` accept two optional arguments:

-  **precision** — max number of digits after the decimal point in
   coordinates, ``6`` by default.
-  **dimensions** — number of dimensions in coordinates, ``2`` by
   default.

Tests

.. code:: bash

py.test -v

The tests run through all .json files in the fixtures directory, comparing each original GeoJSON with an encoded/decoded one.

.. |Build Status| image:: https://travis-ci.org/mapbox/pygeobuf.svg?branch=master :target: https://travis-ci.org/mapbox/pygeobuf .. |Coverage Status| image:: https://coveralls.io/repos/mapbox/pygeobuf/badge.svg?branch=master :target: https://coveralls.io/r/mapbox/pygeobuf?branch=master