Class: QgsRasterIterator

class qgis.core.QgsRasterIterator(input: QgsRasterInterface)

Bases: sip.wrapper

Constructor for QgsRasterIterator, iterating over the specified input raster source.

QgsRasterIterator(QgsRasterIterator)

Iterator for sequentially processing raster cells.

Parameters

input –

DEFAULT_MAXIMUM_TILE_HEIGHT = 2000
DEFAULT_MAXIMUM_TILE_WIDTH = 2000
input(self) → QgsRasterInterface

Returns the input raster interface which is being iterated over.

Return type

QgsRasterInterface

maximumTileHeight(self) → int

Returns the minimum tile width returned during iteration.

See also

setMaximumTileHeight()

See also

maximumTileWidth()

Return type

int

maximumTileWidth(self) → int

Returns the maximum tile width returned during iteration.

See also

setMaximumTileWidth()

See also

maximumTileHeight()

Return type

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 (int) – 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

Return type

Tuple[bool, int, int, QgsRasterBlock, int, int]

Returns

false if the last part was already returned

setMaximumTileHeight(self, h: int)

Sets the minimum tile height returned during iteration.

See also

maximumTileHeight()

See also

setMaximumTileWidth()

Parameters

h (int) –

setMaximumTileWidth(self, w: int)

Sets the maximum tile width returned during iteration.

See also

maximumTileWidth()

See also

setMaximumTileHeight()

Parameters

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 (int) – number of raster band to read

  • nCols (int) – number of columns

  • nRows (int) – number of rows

  • extent (QgsRectangle) – area to read

  • feedback (QgsRasterBlockFeedback = None) – optional raster feedback object for cancellation/preview. Added in QGIS 3.0.

stopRasterRead(self, bandNumber: int)

Cancels the raster iteration and resets the iterator.

Parameters

bandNumber (int) –