Canadian Digital Elevation Data (CDED) Reader/Writer

Licensing options for this format begin with FME Professional Edition.

Note: The CDED format has a fixed coordinate system: LL-83. Any features given to the CDED writer will be reprojected to this coordinate system.


CDED is a raster format with no provision for storing user-defined attributes for the data.

All CDED information is contained within one file, beginning with a metadata header. The data is stored in profiles, each of which has its own metadata header. A profile is one column in the raster. CDED files typically have a .dem extension.

Two versions of CDED are recognized by FME:

  • the original CDED specifications distributed by CTI, and
  • the CDED-1 specifications distributed by GeoBase.

Reader Overview

The CDED reader creates FME feature data from a CDED file specified by the reader dataset. FME considers a single CDED file to be a dataset.

The CDED reader will read both CDED and CDED-1 files.

Writer Overview

The CDED writer creates and writes feature data to a CDED folder specified by writer dataset.

The writer writes either CDED or CDED-1 files, as specified by the CDED Version writer parameter.

The names of the CDED output files written to the output dataset folder are determined from the FME Feature Type. The folder need not exist before the translation occurs.

Any old CDED files in the folder with the same name are overwritten with the new feature data. The CDED writer distinguishes duplicate output files by appending numbers to the filenames. Please see About Feature Attributes for details.

FME Raster Features

FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data. The topics below describe how FME processes raster data.

About FME Rasters Tiling and Mosaicking
Raster Properties Band Combining and Separating
Band Properties Band and Palette Selection
Palette Properties Raster Processing
Compression Raster versus Vector Features
Pyramiding Raster File Naming
Interleaving World Files
Interpretation and Data Type TAB Files
Palette Resolution  

CDED only supports rasters with a single numeric band.