Landmark Z-Map Grid Reader/Writer

FME reads and writes data in Z-Map Grid (raster) format.

To read or write vector data using the Z-Map format, use the Landmark Z-Map Vector Reader/Writer.

Overview

Z-Map Grid files are raster files that typically contain elevation data. Each pixel in the raster represents a single value.

The reader and writer support the following band types:

  • Byte
  • UInt16
  • Int16
  • UInt32
  • Int32
  • Real32
  • Real64

Z-Map Grid does not support storing rotation as an attribute; therefore, rotation is applied to the output data as an affine transformation.

Reader Overview

Two separate readers are required to read Z-Map files: a Landmark Z-Map Vector reader, and a Landmark Z-Map Grid reader.

  • The Z-Map Grid reader reads raster features into FME.
  • Features are read from a single .dat file and separated into Grid and Header features (as well as Comment and History features if they exist).
  • The Z-Map Grid reader converts all values to REAL64 before writing.

Writer Overview

FME provides separate writers to write Z-Map files: a Landmark Z-Map Vector writer, and a Landmark Z-Map Grid writer.

  • Vector Data: Use the Landmark Z-Map Vector writer.
  • Raster Data: Use the Landmark Z-Map Grid writer.

This writer documentation applies only to the Z-Map Grid writer. Refer to the Landmark Z-Map Vector writer documentation for information about writing non-raster data.

  • FME considers a dataset to be a folder name. This folder does not have to exist before you run the translation: FME will create it.
  • The feature type of each dataset is the filename. Note that any existing files in the folder that have the same name are overwritten with the new feature data.
  • The Z-Map Grid writer distinguishes duplicate output files by appending numbers to the filenames.
  • The Z-Map Grid writer converts all values to REAL64 before writing.

FME Raster Features

FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data.

For comprehensive information about how FME processes raster data, see Rasters.

Z-Map Grid files can be written with non-square pixel dimensions.

Z-Map Grid only supports rasters with a single band. Z-Map Grid does not support palettes or Ground Control Points. The Z-Map Grid writer will warn about the presence of Ground Control Points. It is an error if palettes or multiple bands are present in the input feature.

Z-Map Grid does not support rotation; therefore, if rotation is present, it is applied to the output data as an affine transformation.