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.

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

shade(self, redValue: float, greenValue: float, blueValue: float, alphaValue: float) -> (bool, Optional[int], Optional[int], Optional[int], Optional[int]) Generates an new RGBA value based on an original RGBA value.

Parameters:

redValue – The red component of the original value to base a new RGBA value on
greenValue – The green component of the original value to base a new RGBA value on
blueValue – The blue component of the original value to base a new RGBA value on
alphaValue – 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