TAB Files

Raster TAB files are used to store control points, a coordinate system, and user attributes.

Most raster format readers will read TAB files present alongside a raster dataset, and most raster format writers have an option to generate a TAB file to accompany the output dataset. See individual format quick facts tables and feature type topics for more information on TAB file support.

The control points represent georeferencing information for the raster. When reading this information, FME will attempt to determine if these control points represent the extents of the raster (that is, they occur at the corners of the raster), or if they are Ground Control Points (GCPs), and then apply this information accordingly.

Note: Georeferencing information will be discarded for datasets that contain multiple subdatasets, as there is no way to determine which subdataset the information corresponds to.

Attributes are not natively a part of raster TAB files. However, FME will read and write attributes to raster TAB files in the same manner as it does for vector TAB files. This enables the storage of user attributes for many formats that do not otherwise support attribution. To determine whether a raster format can store user attribute information via TAB files, see the User Attributes row in Quick Facts tables:

Information in TAB files will be given more precedence than information in the raster dataset. For example, if the TAB file stores georeferencing information that is different than that from the source dataset, it is the TAB file georeferencing that will be applied to the raster. If this is not desired, a simple workaround is simply to move or rename the TAB file so it will not be read by the format reader

Note: Readers that read both world and TAB files will give more precedence to the world file.