RasterPaletteInterpretationCoercer
Alters the underlying interpretation of the palettes of the raster geometry on the input features, using the specified conversion options.
For example, an input raster feature with a single band with a single palette of interpretation RGB24 could be converted to a single band with a single palette of RGB64 or String data.
Parameters
Destination Interpretation Type
Selects the destination interpretation along with the bit depth. Different interpretations allow for different conversion options to be used.
RGBA to RGB
Selects the action to perform when converting an RGBA palette to an RGB palette. The Drop the alpha band option simply discards the alpha component from the palette. The Apply the alpha band option multiplies all RGB values with their corresponding, normalized alpha value.
RGB to RGBA
Selects the action to perform when converting an RGB palette to an RGBA palette:
- Create opaque alpha adds a new alpha component which has the maximum value for the data type in all palette entries.
- Create alpha component from nodata adds a new alpha component which has the maximum value for the data type in all palette entries except the nodata entry. Note that when this option is selected, all selected input bands have a nodata value.
Convert from Color to Color
Selects the action to undertake when a conversion between different color types occurs.
- Cast: Uses C-style casts to convert the values.
- Bounded cast: Uses C-style casts to convert the values too, but also validates that the source values fit into the destination type, effectively preventing underflow and overflow; if a source value does not fit, the corresponding destination value will either be set to its type's minimum or maximum value.
- Scale by data values: Finds the minimum and maximum values of the source values and uses them to scale the values to the full range of the destination type.
- Scale by data type: Scales the source values while preserving all proportions in regard to the source and destination types' range.
Convert from Float to Integer
Specifies the action to perform when converting from a floating-point value to an integer.
- Round rounds to floating-point value to the nearest integer.
- Ceiling gets the next integer which is greater than or equal to the floating-point value.
- Floor gets the next integer which is less than or equal to the floating-point value.
Usage Notes
Each RasterPaletteInterpretationCoercer performs a conversion on the input raster. If multiple RasterPaletteInterpretationCoercers are used in sequence, then multiple conversions will take place; data quality and translation performance may suffer.
This transformer supports raster band and palette selection. The RasterSelector can be used to modify selection.
The RasterInterpretationCoercer performs similar operations on the raster as a whole, such as converting 4 bands directly to RGBA.
The RasterBandInterpretationCoercer performs similar conversions on individual bands.
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.
Transformer Categories
FME Licensing Level
FME Professional edition and above
Transformer History
This transformer replaces the RasterDataTypeCoercer and RasterColorModelCoercer transformers.
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Search for samples and information about this transformer on the FME Knowledge Center.
Tags Keywords: raster grid band channel palette lookup LUT colormap colourmap datatype convert coerce adjust interpretation colormodel colourmodel bitdepth rescale scale