# MapInfo TAB and MIF/MID

Driver short name

MapInfo File

Driver built-in by default

This driver is built-in by default

MapInfo datasets in native (TAB) format and in interchange (MIF/MID) format are supported for reading and writing. Update of existing TAB files is supported (append of new features, modifications and deletions of existing features, adding/renaming/deleting fields, ...). Update of existing MIF/MID files is not supported.

Note: In the rest of this document "MIF/MID File" is used to refer to a pair of .MIF + .MID files, and "TAB file" refers to the set of files for a MapInfo table in binary form (usually with extensions .TAB, .DAT, .MAP, .ID, .IND).

The MapInfo driver treats a whole directory of files as a dataset, and a single file within that directory as a layer. In this case the directory name should be used as the dataset name.

However, it is also possible to use one of the files (.tab or .mif) in a MapInfo set as the dataset name, and then it will be treated as a dataset with one single layer.

MapInfo coordinate system information is supported for reading and writing.

## Driver capabilities

Supports Create()

This driver supports the `GDALDriver::Create()` operation

Supports Georeferencing

This driver supports georeferencing

Supports VirtualIO

This driver supports virtual I/O operations (/vsimem/, etc.)

## Creation Issues

The TAB File format requires that the bounds (geographical extents) of a new file be set before writing the first feature.

There is currently no automated setting of valid default bounds for each spatial reference system, so for the time being, the MapInfo driver sets the following default bounds when a new layer is created:

- For a file in LAT/LON (geographic) coordinates: BOUNDS (-180, -90) (180, 90)

- For any other projection: BOUNDS (-30000000 + false_easting, -15000000 + false_northing) (30000000 + false_easting, 15000000 + false_northing)

It is possible to override those bounds through two mechanisms.

- specify a user-defined file that contain projection definitions with bounds. The name of this file must be specified with the `MITAB_BOUNDS_FILE` configuration option. This allows users to override the default bounds for existing projections, and to define bounds for new projections not listed in the hard-coded table in the driver. The format of the file is a simple text file with one CoordSys string per line. The CoordSys lines should follow the MIF specs, and MUST include the optional Bounds definition at the end of the line, e.g.

      # Lambert 93 French bounds
      CoordSys Earth Projection 3, 33, "m", 3, 46.5, 44, 49.00000000002, 700000, 6600000 Bounds (75000, 6000000) (1275000, 7200000)

  It is also possible to establish a mapping between a source CoordSys and a target CoordSys with bounds. Such a mapping is specified by adding a line starting with "Source = " followed by a CoordSys (spaces before or after the equal sign do not matter). The following line should start with "Destination = " followed by a CoordSys with bounds, e.g.

      # Map generic Lambert 93 to French Lambert 93, Europe bounds
      Source      = CoordSys Earth Projection 3, 33, "m", 3, 46.5, 44, 49, 700000, 6600000
      Destination = CoordSys Earth Projection 3, 33, "m", 3, 46.5, 44, 49.00000000001, 700000, 6600000 Bounds (-792421, 5278231) (3520778, 9741029)

- use the `BOUNDS` layer creation option (see below)

If no coordinate system is provided when creating a layer, the projection case is used, not geographic, which can result in very low precision if the coordinates really are geographic. You can add "-a_srs WGS84" to the ogr2ogr commandline during a translation to force geographic mode.

MapInfo feature attributes suffer a number of limitations:

- Only Integer, Real and String field types can be created. The various list, and binary field types cannot be created.

- For String fields, the field width is used to establish storage size in the .dat file. This means that strings longer than the field width will be truncated

- String fields without an assigned width are treated as 254 characters.

### Dataset Creation Options

- FORMAT=[TAB/MIF]: To create MIF/MID instead of TAB files

- SPATIAL_INDEX_MODE=[QUICK/OPTIMIZED]: Defaults to `QUICK`. In QUICK mode writing files can be about 5 times faster, but spatial queries can be up to 30 times slower. This can be set to OPTIMIZED to generate optimized spatial index.

- BLOCKSIZE=[512/1024/.../32256]: Defaults to `512`. (multiples of 512) Block size for .map files. MapInfo 15.2 and above creates .tab files with a blocksize of 16384 bytes. Any MapInfo version should be able to handle block sizes from 512 to 32256.

### Layer Creation Options

- BOUNDS=<xmin,ymin,xmax,ymax>: Define custom layer bounds to increase the accuracy of the coordinates. Note: the geometry of written features must be within the defined box.

- ENCODING=value: Define the encoding for field names and field values. The encoding name is specified in the format supported by `CPLRecode()` (e.g. ISO-8859-1, CP1251, CP1252 ...) and internally converted to MapInfo charsets names. Default value is '' that equals to 'Neutral' MapInfo charset.

- DESCRIPTION=value: (GDAL >= 3.1.0) Friendly layer name (only for TAB format). Friendly names can be up to 256 characters long and can include most ASCII characters. Supported by MapInfo Pro v15.0 or higher.

### Configuration options

The following configuration options are available:

- MITAB_BOUNDS_FILE=value: See Creation Issues.

- MITAB_SET_TOWGS84_ON_KNOWN_DATUM=[YES/NO]: (GDAL >= 3.0.3) The default behavior, starting with GDAL 3.0.3, is NO. That is, the TOWGS84 parameters read from the .tab header will not be set on the Datum object of the CRS, when the datum can be inferred.

### See Also

- MITAB Page

- About friendly layer names