Introducing export file formats
Koordinates support multiple file formats for export. Below, we provide a brief introduction to some of the file formats we support.
The file format you choose will depend on what you want to do with your data, as well as which software programme you will be using.
Quick overview of export file formats
Koordinates supports the following file formats for downloading data, grouped under five main categories.
- Shapefile (.SHP) (.DBF for tabular data)
- MapInfo TAB (.TAB)
- MapInfo TAB for Images/Rasters (.TAB)
- Esri File Geodatabase (FGDB)
- GeoPackage / SQLite
- Esri ASCII Grid
- DWG with linked JPEG's for images/rasters
- Google Earth KML
- CSV and GeoCSV
MapInfo TAB is a proprietary format used for vector datasets, and is primarily for use in the suite of MapInfo GIS applications.
Like other GIS file formats, TAB files contain a few different kinds of file formats, which each do a different work. These include:
- .tab: The main file that links all the other files in the dataset
- .dat: This file stores the attribute data - that is, the the non-spatial data in your dataset
- .id: This links graphic data to the database information
- .map: This has the geographic information that enables the data to be represented on a map.
- .ind: This is an index file for tabular data
A GeoTIFF file is a georeferenced TIFF, which means it can have geographic information such as map projections embedded within the TIFF itself. This means that a GIS application can position the image in the correct location
TIFF is an open and non-proprietary file format that is widely used for raster imagery and aerial photography. Strictly speaking, GeoTIFF is a metadata format, but the TIFF format enables both the data and metadata to exist in the same file.
Shapefile is a GIS format developed for vector datasets. It should work in most common GIS applications.
Your Shapefile download will contain a range of different file formats, which each do a different kind of work within your application. These are:
- .shp: this file represents the feature geometry - i.e. the points, lines and polygons in spatial dataset.
- .shx: this file represents the ‘shape index position,’ and is used to search forward and backwards.
- .dbf: this is the database file, which contains attribute data and object IDs.
- .prj: this file will contain the projection information.
- .cpg: this identifies the character encoding for the .dbf database file.
GeoPackage / SQLite
Geopackage is a SQLite database format from the Open Geospatial Consortium, which is intended to be a modern alternative to older formats like Shapefile.
Geopackage is an open and platform independent format, and is supported in a range of applications. It is an especially useful format for development of mobile applications for smartphones and tablets.
Esri File Geodatabase (FGDB)
The Esri File Geodatabase is a proprietary Esri database format that is used for more complex uses of GIS datasets in Esri software. This format is often used because it allows for much larger file formats and can provide better performance than Shapefiles.
GeoJPEG’s are JPEG files that have geographic information attached within the file -- that is to say, it is a georeferenced JPEG. When downloaded, the .jpeg file will be accompanied by a .jgw file that will carry the associated geographic information.
JPEG 2000 is the newer version of the JPEG file format, which is intended to provide better compression and image quality than an ordinary JPEG. While JPEG 2000 has some benefits to JPEG, it is not as widely supported as JPEG.
Datasets downloaded in JPEG 2000 will be georeferenced with embedded XML.
KEA is a file format for raster images. It enables compression of the files and can support large file sizes, and can by used in a range of major GIS applications. It also supports raster attribute tables.
ASCII Grid is a proprietary file format from Esri.
DWG is a proprietary file format used for CAD (Computer Aided Design & Drafting) software.
Google Earth KML
KML, or Keyhole Markup Language, is a proprietary file format primarily used in Google Earth applications. KML is used to annotate three dimensional Earth browsers, of which Google Earth is the most widely used. KML files from Koordinates are exported in a .kmz file format, which is a zipped KML.
CSV and GeoCSV
Comma Separated Value format - or CSV - is a format that enables tabular data to be easily exchanged by different applications. GeoCSV is its geospatial extension.
The Koordinates implementation of CSV supports:
- UTF-8 character encoding
- Vector geometry data in OGC WKT format
- The included VRT file provides some field type information for software that supports it
- Special characters formatting, such as literal commas and new lines.
The Koordinates implementation of CSV has the following limitations:
- Primary keys and fields constraints (e.g such as NOT NULL) are not listed in the VRT schema
- Byte Order Mark header (for UTF-8 support) cannot be read by some software packages.