A small tool to minify (compress) a GeoJSON file by:
- Removing non-significant whitespace
- Reducing the number of decimals used for coordinates: option
-c 5to keep 5 decimals - Minify the length of the keys by mapping each key name to a single or double letter combination: option
-kconverts long property keys such asmy_long_property_nametoaorab. Warning: If you already have property keys likeaorb, it may map them to the wrong name. - Blacklist keys, i.e. remove these keys from the output
- Whitelist keys, i.e. only keep these keys in the output
- Filter features, i.e. only keep those features whose properties satisfy certain conditions.
The tool works in two modes: for files that require reprojection or topojson output, it will read in all data at once. In case your GeoJSON file is too large for node.js to handle, this may fail. That's why it normally uses a streaming mode, so also large files can be processed easily (after which you can try reprojecting it again).
To run it standalone:
npm i -g minify-geojsonAfter which the minify-geojson command should be available.
Alternatively, you can fork/download/clone the repository, and execute:
npm install
npm link
npm run watchAny changes in the Typescript code will be compiled, and since you've linked the project, you can use the minify-geojson command from the command line too.
Minify GeoJSON
Minify (compress) each input GeoJSON or ESRI shapefile by replacing the
attribute keys with a shorter representation (typically, its first letter).
You can also reduce the number of decimals for coordinates and properties,
whitelist and blacklist or filter certain properties. Output can be GeoJSON
or TopoJSON. If you wish to reproject to WGS84, you can supply the EPSG code
(which will be resolved via
http://www.spatialreference.org/ref/epsg/YOURCODE/proj4/).
Options
-k, --keys Boolean Minify property keys, e.g. id remains id, telephone
becomes t, address a etc.
-i, --includeKeyMap Boolean Add the key map to the GeoJSON file. Requires the -k
flag too.
-t, --topo Boolean Output format is TopoJSON instead of GeoJSON.
-r, --reproject String Reproject to WGS84 by supplying the input EPSG
coordinate system, e.g. -r EPSG:28992.
-f, --filter String Comma separted list of property filters, which will
KEEP those features when the property filter returns
true, e.g. filter "WATER = NO" will filter out
feature\'s where { "WATER": "NO" }.
-b, --blacklist String Comma separated list of properties that should be
removed (others will be kept). Note that keys will not
be minified unless the -k flag is used too.
-w, --whitelist String Comma separated list of properties that should be kept
(others will be removed). Note that keys will not be
minified unless the -k flag is used too.
-c, --coordinates Positive number Only keep the first n digits of each coordinate.
-d, --decimals Positive number Only keep the first n digits of each decimal property.
-s, --src File names Source files to process: default option, you do not need to
supply the -s flag.
-v, --verbose Boolean Output is verbose.
Examples
01. Shrink property keys and output to $ minify-geojson -k original.geojson
original.min.geojson
02. A verbose version $ minify-geojson -kv original.geojson
03. Prune the blacklisted properties $ minify-geojson -b "property1, property2"
original.geojson
04. Keep the whitelisted properties $ minify-geojson -w "property1, property2"
original.geojson
05. Removes superfluous decimals (keep $ minify-geojson -c 5 original.geojson
first 5)
06. Add the key mapping to the output $ minify-geojson -ki original.geojson
07. Convert output to topojson (-i and -c $ minify-geojson -kt original.geojson
are not used)
08. Reproject shape file in RD (EPSG:28992) $ minify-geojson -ktv -r 28992 original.shp
to TopoJSON
09. Filter based on properties $ minify-geojson -ktv -r 28992 -f "WATER =
NO, CITY=Amsterdam" -b "WATER, CITY"
original.shp
10. Full example $ minify-geojson -ktiv -w "property1,
property2" -c 5 original.geojson