Class: QgsRasterTransparency

class qgis.core.QgsRasterTransparency

Bases: sip.wrapper

Constructor for QgsRasterTransparency.

QgsRasterTransparency(QgsRasterTransparency)

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

Enums

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.

Signals

Attributes

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 – the needle to search for in the transparency hay stack
  • globalTransparency – 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
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.

isEmpty(self) → bool

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

readXml(self, elem: QDomElement)

Reads the transparency information from an XML document.

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

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

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

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

transparentSingleValuePixelList(self) → object

Returns the transparent single value pixel list.

transparentThreeValuePixelList(self) → object

Returns the transparent three value pixel list.

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

Writes the transparency information to an XML document.