[GIS] Lossless conversion from shapefiles to XML/JSON/Text

gdalogr2ogrshapefile

I'm a software developer and I need to create a custom tool that imports ESRI shapefiles (shp + shx + dbf), manipulates the content and then exports new shapefiles.
To avoid a complex binary reading of the 3 formats, I'd like to convert the input files into a "well known" textual format (JSON, XML, plain text, …) and I want to be able to revert the conversion.

I tried to use gdal/ogr2ogr to convert the shapefiles into CSV but the output seems to only include the content of the database (dbf file). This means that, if I try to convert the CSV back into shapefiles, I lose all the polygon coordinates.

I then tried to convert to GeoJSON, which was much better but a few data appear to be missing again (like shape boundaries and polygon indexes).

Is there an option in gdal for a "lossless" conversion between shapefiles and any humanly readable format?

Best Answer

All of the vector formats supported by GDAL/OGR are listed here. With each driver, check out the creation options to control the output. These are passed to ogr2ogr using -dco and -lco flags.

Good text-based output drivers include:

CSV - be sure to use -lco GEOMETRY=AS_WKT to get the well-known text geometry
GeoJSON
GML
KML
LIBKML.

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[GIS] Gdal ogrinfo CSV unable to open datasource

Ok. I think the problem is with the Gdal-Bin version. I tried in the same environment another csv file but with comma separator, not semicolon, and it worked.

Then I tried the "test.csv" with semicolon separator in my home pc, with the version of gdal-bin 1.7.3-6ubuntu3, and it was imported perfectly.

So my conclusion is that the gdal-bin version 1.6.3-4build1 has some problems importing CSV files with semicolon separator.

Thank you all for your comments.

[GIS] Bulk csv to shapefile (using ogr2ogr)

A modern-enough GDAL can convert CSV files directly into shapefiles. For the test.csv file in the documentation, http://www.gdal.org/drv_csv.html - you can do:

ogr2ogr -s_srs EPSG:4326 -t_srs EPSG:3857 -oo X_POSSIBLE_NAMES=Lon* -oo Y_POSSIBLE_NAMES=Lat*  -f "ESRI Shapefile" test.shp test.csv

to create test.shp (and .dbf et al) from test.csv, converting from EPSG:4326 to EPSG:3857 as it goes.

You seem to be using Windows command syntax to loop over your files, which I dont know, but all you need to change is the destination and source names for each shapefile.

In a unix shell the relevant loop syntax is:

for f in *.csv ; do echo $f ${f%csv}shp ; done

(replace echo with your command, and put "$f" and "${f%csv}shp" where you want the csv and shapefile in the command)

Best Answer

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[GIS] Gdal ogrinfo CSV unable to open datasource

[GIS] Bulk csv to shapefile (using ogr2ogr)

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