RasterConversionOperator Class
An operator that converts raster features between different formats, and manipulates raster values and other raster properties.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CEOperators assembly)
Syntax
public class RasterConversionOperator : UnaryOperatorRemarks
A RasterConversionOperator can convert raster features between different representations, do some basic manipulation of raster values, change the undefined value property of the rasters, and change whether the rasters are continuous. The operator modifies only raster features, so features with other geometry types are passed through without modification.
Format conversion
If the ChangeRasterFormat property is True, all input rasters will converted to the format specified by NewRasterFormat. Please see RasterFormat for details on supported raster formats.
All conversions between integer and floating point rasters are supported. Floating point values will be rounded to the nearest integer value. Output values will be clamped to an interval determined by the minimum and maximum values for the output format, and the MinValue and MaxValue properties.
Integer and floating point rasters can be converted to RGB or RGBA formats, provided that color information is present. The color information may be supplied as a palette attached to the input raster, or as a RasterVisualizer with a color table, typically created by the dataset the raster feature was read from or attached by a VisualizationOperator. If no color information is present, an exception will be thrown.
Conversions between RGB and RGBA are supported. However, conversions from RGB or RGBA to any integer or floating point format are not supported and will throw exceptions.
Raster value manipulation
Whether the raster format is changed or not, this operator can do some simple manipulations of cell values in integer and floating point rasters. The cell values will by multiplied by Factor and Offset will be added to the result. Finally each cell value will be clamped to an interval determined by the minimum and maximum values for the output raster, and the MinValue and MaxValue properties.
The offset and factor will be applied to the undefined cell values. To avoid this set the ChangeUndefinedValue property to PropertyAndCellValues and NewUndefinedValue to a non-empty value.
For RGB and RGBA rasters, these properties are ignored.
Undefined value manipulation
If the ChangeUndefinedValue property is OnlyProperty, the operator will also change the Raster.UndefinedValue property of the rasters to the value specified by NewUndefinedValue (which may be null).
If you want all undefined pixels in the input raster to remain undefined in the output, you can in most cases leave the ChangeUndefinedValue to the default No setting. There are some exceptions to this. One is when the Offset or Factor properties are non-default which is discussed in previous section. Another is when the old undefined value lies outside the range of the new raster (either due to using the MinValue or MaxValue properties, or due to lower bitdepth of the new format). In these cases, the undefined values should be updated by using the PropertyAndCellValues setting combined with NewUndefinedValue property.
A special case is when changing format from RGB to RGBA. If ChangeUndefinedValue is set to PropertyAndCellValues, and the input raster has an integer undefined value set, the alpha channel will be set to 0 instead of 255 for all cells where the RGB value matches the undefined value. You may in some cases need to use two RasterConversionOperator instances: one to set the desired undefined value on the RGB rasters, and a second one to do the RGBA conversion.
Changing whether the rasters are continuous
Rasters have a boolean property, Raster.Continuous, that the operator can change via ChangeContinuous and NewContinuous.
Inheritance Hierarchy
System.Object (not available in C#)
EngineObject
Operator
UnaryOperator
RasterConversionOperator
Platforms
Windows, Linux, Android
RasterConversionOperator Members
The RasterConversionOperator type has the following members.
Constructors
| Name | Description |
|---|---|
| RasterConversionOperator | Initializes a new instance of the RasterConversionOperator class. |
Properties
| Name | Description |
|---|---|
| ChangeContinuous | Gets or sets a flag indicating if the continuous property of rasters should get the new value specified by NewContinuous. |
| ChangeRasterFormat | Gets or sets a flag indicating if rasters should be converted to the new format specified by NewRasterFormat. |
| ChangeUndefinedValue | Gets or sets a flag indicating if the undefined value of the rasters should be changed. |
| Description | Gets or sets a short description of the operator. Inherited from Operator |
| DisplayName | Gets or sets a display name for the operator. Inherited from Operator |
| Factor | Gets or sets a value that will be multiplied to all cell values. |
| Input | Gets or sets the input operator, from which this operator reads features. Inherited from UnaryOperator |
| IsDisposed | Gets a value that tells whether the current RasterConversionOperator has been disposed. Inherited from EngineObject |
| IsoMetadataDocument | Gets or sets the path to an ISO 19139 metadata document for the operator. Inherited from Operator |
| MaxValue | Gets or sets a maximum cell value that will be written to the output rasters. |
| MinValue | Gets or sets a minimum cell value that will be written to the output rasters. |
| Name | Gets or sets the name of the operator. Inherited from Operator |
| NativeHandle | Gets the native Carmenta Engine kernel object the current RasterConversionOperator represents. Inherited from EngineObject |
| NewContinuous | Gets or sets a new value for the continuous property of the rasters. |
| NewRasterFormat | Gets or sets a value specifying which format the rasters should be converted to. |
| NewUndefinedValue | Gets or sets a value specifying a new undefined value of the converted rasters. |
| Offset | Gets or sets an offset value that will be added to all cell values. |
| IUserProperties.UserProperties | Gets the AttributeSet that contains the user properties. Inherited from IUserProperties |
Methods
| Name | Description |
|---|---|
| Clone | Creates a copy of an object. Inherited from EngineObject |
| Dispose | Releases the reference to the native Carmenta Engine kernel instance the EngineObject represents. Inherited from EngineObject |
| Equals | Determines whether this instance is equal to another. Inherited from EngineObject |
| FindChildObject | Overloaded. Finds the child object with the specified name. Inherited from Operator |
| FlushCache | Marks the layer as flushed which will release cached resources during the next update. Inherited from Operator |
| GetChildObjects | Overloaded. Gets the child objects of the current object. Inherited from Operator |
| GetFeatures | Overloaded. Gets features from the operator chain. Inherited from Operator |
| GetLocalizedDescription | Gets a localized version of the operator description in a specific language. Inherited from Operator |
| GetLocalizedDisplayName | Gets a localized version of the operator display name in a specific language. Inherited from Operator |
| GetLocalizedIsoMetadataDocument | Gets the path to an ISO 19139 metadata document for a specific language. Inherited from Operator |
| GetRasterFeature | Overloaded. Gets raster features from the operator chain and merges them into a single raster. Inherited from Operator |
| HasLocalizedDescription | Checks if a localized version of the operator description is available in a specific language. Inherited from Operator |
| HasLocalizedDisplayName | Checks if a localized version of the operator display name is available in a specific language. Inherited from Operator |
| HasLocalizedIsoMetadataDocument | Checks if an ISO 19139 metadata document is available for a specific language. Inherited from Operator |
| SetLocalizedDescription | Sets a operator description in a specific language. Inherited from Operator |
| SetLocalizedDisplayName | Sets a operator display name in a specific language. Inherited from Operator |
| SetLocalizedIsoMetadataDocument | Sets the path to an ISO 19139 metadata document for the operator, for a specific language. Inherited from Operator |