Class: QgsRasterShaderFunction¶

The raster shade function applies a shader to a pixel at render time - typically used to render grayscale images as false color.

Class Hierarchy¶

Subclasses¶

QgsColorRampShader

A ramp shader will color a raster pixel based on a list of values ranges in a ramp.

Methods

`labelPrecision`	Returns label precision
`maximumValue`	Returns the minimum value for the raster shader.
`minimumMaximumRange`
`minimumValue`	Returns the maximum value for the raster shader.
`setLabelPrecision`	Sets label precision to labelPrecision

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsRasterShaderFunction. See the FAQ for more details.

`legendSymbologyItems`	Returns legend symbology items if provided by renderer.
`setMaximumValue`	Sets the maximum value for the raster shader.
`setMinimumValue`	Sets the minimum value for the raster shader.
`shade`	Generates an new RGBA value based on one input value.

class qgis.core.QgsRasterShaderFunction[source]¶

Bases: object

labelPrecision(self) → int[source]¶

Returns label precision

Added in version 3.16.

Return type:: int

virtual legendSymbologyItems(self) → List[Tuple[str, QColor]][source]¶

Returns legend symbology items if provided by renderer.

Return type:: List[Tuple[str, QColor]]

maximumValue(self) → float[source]¶

Returns the minimum value for the raster shader.

See also

setMinimumValue()

See also

maximumValue()

Return type:: float

minimumMaximumRange(self) → float[source]¶

Return type:: float

minimumValue(self) → float[source]¶

Returns the maximum value for the raster shader.

See also

setMaximumValue()

See also

minimumValue()

Return type:: float

setLabelPrecision(self, labelPrecision: int)[source]¶

Sets label precision to labelPrecision

Added in version 3.16.

Parameters:: labelPrecision (int)

virtual setMaximumValue(self, value: float)[source]¶

Sets the maximum value for the raster shader.

See also

setMinimumValue()

See also

maximumValue()

Parameters:: value (float)

virtual setMinimumValue(self, value: float)[source]¶

Sets the minimum value for the raster shader.

See also

setMaximumValue()

See also

minimumValue()

Parameters:: value (float)

virtual shade(self, value: float)[source]¶

Generates an new RGBA value based on one input value.

Parameters:

value (float) -> (bool) – The original value to base a new RGBA value on

Returns:

True if the return values are valid otherwise False
returnRedValue: The red component of the new RGBA value
returnGreenValue: The green component of the new RGBA value
returnBlueValue: The blue component of the new RGBA value
returnAlpha: The alpha component of the new RGBA value

virtual shade(self, redValue: float, greenValue: float, blueValue: float, alphaValue: float)[source]

Generates an new RGBA value based on an original RGBA value.

Parameters:

redValue (float) – The red component of the original value to base a new RGBA value on
greenValue (float) – The green component of the original value to base a new RGBA value on
blueValue (float) – The blue component of the original value to base a new RGBA value on
alphaValue (float) -> (bool) – The alpha component of the original value to base a new RGBA value on

Returns:

True if the return values are valid otherwise False
returnRedValue: The red component of the new RGBA value
returnGreenValue: The green component of the new RGBA value
returnBlueValue: The blue component of the new RGBA value
returnAlpha: The alpha component of the new RGBA value