Enhances the features of a raster image. The RasterSharpener enhances the borders, lines, and curves while reducing noise in the flat areas of the raster image.

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Typical Uses

  • Medical image processing
  • Computer Vision
  • Image pre-processing

How does it work?

The RasterSharpener accepts features with raster geometry. All other geometry types will be rejected.

Each input raster feature will be processed independently.

The RasterSharpener uses an Anisotropic Diffusion algorithm to sharpen the image.

Useful as a pre-processing step for the RasterSegmenter.

Bands, Cell types, and Palettes

Rasters may have one band or multiple bands. The RasterSharpener can handle up to 4 bands of the same datatype. Alpha bands are preserved by removing them from the input raster prior to processing and appending them to the output raster after processing is complete. Input rasters with an unexpected number of bands or with inconsistent types, will be rejected.

All raster cell types are accepted as input but the algorithm internally uses Real64 data. A preserve interpretation option is provided, that, when enabled, converts the raster back to the same interpretation as the input raster.

Rasters may have no palette, one palette, or multiple palettes. For more information on raster structure, see Rasters (IFMERaster). The RasterSharpener will resolve palettes on input rasters prior to processing. Input rasters with string palette values on cannot be resolved and will be rejected.

Selecting Raster Bands and Palettes

To select specific bands and/or palettes, use the RasterSelector prior to the RasterSegmenter.


Attributes from the input features will be preserved in the output feature.

Usage Notes

Choosing a Raster Transformer

FME has an extensive selection of transformers for working with raster data. They can be generally categorized as working with whole rasters, bands, cells or palettes, and those designed for workflow control or combining raster with vector data.

For information on raster geometry and properties, see Rasters (IFMERaster).


Input Ports

Output Ports


Editing Transformer Parameters

Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.

Dialog Options - Tables

Transformers with table-style parameters have additional tools for populating and manipulating values.


Processing Behavior


Feature Holding


Dependencies None

FME Community

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Search for all results about the RasterSharpener on the FME Community.


Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.