ER Mapper ECW Writer Feature Type Parameters

To access feature type parameters, click the gear icon on a feature type in the workspace. This opens the Feature Type Parameter Editor.

Tip  To always display the editor in FME Workbench, you can select View > Windows > Parameter Editor.

General

All feature types share similar General parameters, which may include Feature Type Name, Reader or Writer information, and Geometry.

In most Writer Feature Type parameter dialogs, you can also control Dynamic Schema Definitions. Some database formats accept Table or Index Qualifier prefixes on the output table feature type.

Important  These parameters apply only to a selected feature type, not to the entire writer. If a feature type parameter listed here conflicts with a writer-level parameter, then the writer parameter will be ignored and this feature type parameter will be used.

Raster

ECW Format Version

This parameter sets the version of the output ECW file. Versions 2 and 3 are supported.

Default: 3

Compress By Percentage

This option sets the desired compression level and quality of the output image. This is expressed as a percentage of the original file size. For example, setting a compression level of 75 means that the output image will be approximately 75% smaller than an uncompressed image (that is, it will be about one-quarter the size of the uncompressed image).

The range of the value is from 0 (best quality) to 99 (worst quality). The default value is 75.

Note: This value only represents the targeted compression level, and this may not actually be achieved. Also note that ECW does not support lossless compression; that is, even if a compression level of 0 is specified, the output ECW file may not be identical to the original image.

Note: Repeatedly reading and saving files may decrease the quality for this format. In addition, FME Workbench may not know which format data comes from, and whether it used lossy compression. If you know that source data comes from files with lossy compression, you should also set the compression level to 0. Although this compression still does not guarantee the exact copy of the source file, the output will be very close to the original.

TAB File Generation

Enables or disables the generation of a TAB file, along with the output image.

The value can be Yes or No (default).

Use EPSG Code For Projection

This parameter decides whether the writer will try to use an EPSG code to represent the coordinate system for version 3 ECW files.

  • When Known Good (default) – If the input raster has a coordinate system that can be represented as an EPSG code – and that EPSG code has been confirmed to work with ERDAS software – then the writer will use that EPSG code as the .ecw file’s projection. Otherwise, it will attempt to translate the coordinate system to ER Mapper projection and datum names. This may fail for some less common coordinate systems.

  • Always – If the input raster has a coordinate system that can be represented as an EPSG code, then the writer will use that EPSG code as the .ecw file’s projection. The code will be used regardless of whether it is supported by ERDAS software.

  • Never – The writer will attempt to translate the input raster's coordinate system to ER Mapper projection and datum names. This may fail for some less common coordinate systems.

The set of known-good EPSG codes can be inspected and modified if required. Locate the list in your FME installation folder:

[FME_Install_Folder]/Reproject/ERMapperData/SupportedEpsgSystems.csv