PROJReprojector

This parameter specifies whether to use an Automatic Transformation or Manual Transformation.

For an Automatic Transformation, a source and destination coordinate system are selected and a transformation is chosen automatically by PROJ. For information on how PROJ performs automatic transformations, see the PROJ documentation - Computation of coordinate operations between two CRS.

For a Manual Transformation, a PROJ string must be provided describing the desired transformation.

The source and destination coordinate systems can be specified using any format recognized by PROJ such as EPSG numbers (formatted as EPSG:XXXX), WKT1 or WKT2 strings, and PROJ strings (excluding pipelines). FME will attempt to determine what the destination coordinate system’s corresponding FME coordinate system is and will tag the output features with it, unless an override is specified for the Output Coordinate System Tag.

The transformation can be specified using any PROJ string (including PROJ pipelines with multiple steps) that specifies a valid transformation. See the PROJ Documentation for examples.

Note: When reprojecting rasters or point clouds, the transformation specified here must be invertible.

The coordinate system parameter specifies an FME coordinate system to tag the output features with. This will override the coordinate system selected by FME if an Automatic Transformation is being used. It is optional, but recommended that this parameter is always used when doing Manual Transformations in order to ensure FME handles the resulting features correctly during further processing.

The Interpolation Type affects only raster data. Cell values are interpolated in order to change the raster to the specified size.

• Nearest Neighbor is the fastest but produces the poorest image quality.
• Bilinear provides a reasonable balance of speed and quality.
• Bicubic is the slowest but produces the best image quality.
• Average 4 and Average 16 have a performance similar to Bilinear and are useful for numeric rasters such as DEMs.

The Cell Size applies only to raster features.

• Stretch Cells: The cell size of the raster will be adjusted to maintain the same number of rows and columns in the reprojected raster as there were in the input raster.
• Square Cells: The number of rows and columns as well as the spacing will be changed to maintain approximately the same cell ground area and form square cells where the horizontal and vertical cell sizes are equal.
• Preserve Cells: Like the Square Cells option, this option will change both the number of rows and columns and the spacing to maintain cell ground area, but will also try to preserve the original cell aspect ratio, taking into account any warping caused by the reprojection.

Sets the tolerance, in cells, for approximating cell locations for raster reprojection.

If a value of 0.0 is specified, every cell location in the raster will be reprojected. This is the default.

If a value > 0.0 is specified, rather than reprojecting every single cell location in the raster, some cell locations will be approximated. The difference between an approximated cell location and the true cell location should be at most the tolerance value. For example, if a value of 0.5 is specified, each approximated cell location should be at most half a pixel away from its true location. Specifying a value > 0.0 may improve performance.

Using the Text Editor

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

Text Editor

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

Arithmetic Editor

Conditional Values

Set values depending on one or more test conditions that either pass or fail.

Parameter Condition Definition Dialog

Content

Expressions and strings can include a number of functions, characters, parameters, and more.

When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.

Content Types

String Functions	These functions manipulate and format strings.
Special Characters	A set of control characters is available in the Text Editor.
Math Functions	Math functions are available in both editors.
Date/Time Functions	Date and time functions are available in the Text Editor.
Math Operators	These operators are available in the Arithmetic Editor.
FME Feature Functions	These return primarily feature-specific values.
FME Parameters	FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters	Create your own editable parameters.

Note: Not all tools are available in all transformers.