Class: QgsRasterTransparency

class qgis.core.QgsRasterTransparency

Bases: sip.wrapper

Defines the list of pixel values to be considered as transparent or semi transparent when rendering rasters.

QgsRasterTransparency() Constructor for QgsRasterTransparency.

QgsRasterTransparency(QgsRasterTransparency)

Methods

alphaValue

Returns the transparency value for a single value pixel.

initializeTransparentPixelList

Resets the transparency list to a single value.

isEmpty

True if there are no entries in the pixel lists except the nodata value

readXml

Reads the transparency information from an XML document.

setTransparentSingleValuePixelList

Sets the transparent single value pixel list, replacing the whole existing list.

setTransparentThreeValuePixelList

Sets the transparent three value pixel list, replacing the whole existing list.

transparentSingleValuePixelList

Returns the transparent single value pixel list.

transparentThreeValuePixelList

Returns the transparent three value pixel list.

writeXml

Writes the transparency information to an XML document.

class TransparentSingleValuePixel

Bases: sip.wrapper

QgsRasterTransparency.TransparentSingleValuePixel(QgsRasterTransparency.TransparentSingleValuePixel)

max
min
percentTransparent
class TransparentThreeValuePixel

Bases: sip.wrapper

QgsRasterTransparency.TransparentThreeValuePixel(QgsRasterTransparency.TransparentThreeValuePixel)

blue
green
percentTransparent
red
alphaValue(self, value: float, globalTransparency: int = 255)int

Returns the transparency value for a single value pixel.

Searches through the transparency list, and if a match is found, the global transparency value is scaled by the stored transparency value.

Parameters
  • value (float) – the needle to search for in the transparency hay stack

  • globalTransparency (int = 255) – the overall transparency level for the layer

alphaValue(self, redValue: float, greenValue: float, blueValue: float, globalTransparency: int = 255) -> int Returns the transparency value for a RGB pixel.

Searches through the transparency list, if a match is found, the global transparency value is scaled by the stored transparency value.

Parameters
  • redValue – the red portion of the needle to search for in the transparency hay stack

  • greenValue – the green portion of the needle to search for in the transparency hay stack

  • blueValue – the green portion of the needle to search for in the transparency hay stack

  • globalTransparency – the overall transparency level for the layer

Return type

int

initializeTransparentPixelList(self, value: float)

Resets the transparency list to a single value.

initializeTransparentPixelList(self, redValue: float, greenValue: float, blueValue: float) Resets the transparency list to single red, green, and blue values.

Parameters

value (float) –

isEmpty(self)bool

True if there are no entries in the pixel lists except the nodata value

Return type

bool

readXml(self, elem: QDomElement)

Reads the transparency information from an XML document.

Parameters

elem (QDomElement) –

setTransparentSingleValuePixelList(self, newList: Iterable[QgsRasterTransparency.TransparentSingleValuePixel])

Sets the transparent single value pixel list, replacing the whole existing list.

Parameters

newList (Iterable[QgsRasterTransparency.TransparentSingleValuePixel]) –

setTransparentThreeValuePixelList(self, newList: Iterable[QgsRasterTransparency.TransparentThreeValuePixel])

Sets the transparent three value pixel list, replacing the whole existing list.

Parameters

newList (Iterable[QgsRasterTransparency.TransparentThreeValuePixel]) –

transparentSingleValuePixelList(self)List[QgsRasterTransparency.TransparentSingleValuePixel]

Returns the transparent single value pixel list.

Return type

List[QgsRasterTransparency.TransparentSingleValuePixel]

transparentThreeValuePixelList(self)List[QgsRasterTransparency.TransparentThreeValuePixel]

Returns the transparent three value pixel list.

Return type

List[QgsRasterTransparency.TransparentThreeValuePixel]

writeXml(self, doc: QDomDocument, parentElem: QDomElement)

Writes the transparency information to an XML document.

Parameters
  • doc (QDomDocument) –

  • parentElem (QDomElement) –