Subgroup: Raster

Class: QgsRasterIterator

class qgis.core.QgsRasterIterator

Bases: sip.wrapper

Iterator for sequentially processing raster cells.

Methods

input
maximumTileHeight
maximumTileWidth
readNextRasterPart Fetches next part of raster data, caller takes ownership of the block and caller should delete the block.
setMaximumTileHeight
setMaximumTileWidth
startRasterRead Start reading of raster band.
stopRasterRead

Signals

Attributes

DEFAULT_MAXIMUM_TILE_HEIGHT
DEFAULT_MAXIMUM_TILE_WIDTH
DEFAULT_MAXIMUM_TILE_HEIGHT = 2000
DEFAULT_MAXIMUM_TILE_WIDTH = 2000
input(self) → QgsRasterInterface
maximumTileHeight(self) → int
maximumTileWidth(self) → int
readNextRasterPart(self, bandNumber: int) → Tuple[bool, int, int, QgsRasterBlock, int, int]

Fetches next part of raster data, caller takes ownership of the block and caller should delete the block.

Parameters:
  • bandNumber – band to read
  • nCols – number of columns on output device
  • nRows – number of rows on output device
  • block – address of block pointer
  • topLeftCol – top left column
  • topLeftRow – top left row
Returns:

false if the last part was already returned*

setMaximumTileHeight(self, h: int)
setMaximumTileWidth(self, w: int)
startRasterRead(self, bandNumber: int, nCols: int, nRows: int, extent: QgsRectangle, feedback: QgsRasterBlockFeedback = None)

Start reading of raster band. Raster data can then be retrieved by calling readNextRasterPart until it returns false.

Parameters:
  • bandNumber – number of raster band to read
  • nCols – number of columns
  • nRows – number of rows
  • extent – area to read
  • feedback – optional raster feedback object for cancelation/preview. Added in QGIS 3.0.
stopRasterRead(self, bandNumber: int)