Bandwise Expression

The BandwiseExpression operator performs a pixel-wise mathematical expression on each band of a raster source. For more details on the expression syntax, see the Expression operator. Note that in the BandwiseExpression operator it is only possible to map one pixel value to another and not reference any other pixels or bands. The variable name for the pixel value is x.

Errors

The parsing of the expression can fail if there are, for example, syntax errors.

Parameters

Name	Type	Description	Examples
expression	string	Scalar expression applied to each band value.	"x * 2.0" "ln(1 / x)"
outputType	RasterDataType	Output raster data type for the computed band values.	"F64"
mapNoData	boolean	Whether NO DATA values should be mapped with the expression. Otherwise, they are mapped automatically to NO DATA.	false true

Sources

Name	Type	Description
raster	RasterOperator	An operator that produces raster data.

Examples

{
    "type": "BandwiseExpression",
    "params": {
        "expression": "x * 2.0",
        "outputType": "F64",
        "mapNoData": false
    },
    "sources": {
        "raster": {
            "type": "GdalSource",
            "params": {
                "data": "example"
            }
        }
    }
}