28.1.18. Raster tools

28.1.18.1. Align raster

Aligns raster by resampling it to the same cell size and reprojecting to the same CRS as a reference raster.

Warning

This algorithm is ONLY available in the Model Designer context.

Parameters

Label

Name

Type

Description

Input layer

INPUT

[raster]

Input raster layer to align

Resampling method

RESAMPLING_METHOD

[enumeration]

Default: 0

Method to use for input layer resampling. Available options are:

  • 0 — Nearest Neighbour

  • 1 — Bilinear (2x2 kernel)

  • 2 — Cubic (4x4 kernel)

  • 3 — Cubic B-Spline (4x4 kernel)

  • 4 — Lanczos (6x6 kernel)

  • 5 — Average

  • 6 — Mode

  • 7 — Maximum

  • 8 — Minimum

  • 9 — Median

  • 10 — First quartile (Q1)

  • 11 — Third quartile (Q3)

Rescale values according to the cell size

RESCALE

[boolean]

Default: No

Reference layer

REFERENCE_LAYER

[raster]

A raster layer that will be used to fetch extent, cell size and CRS that will be applied to input layers.

Override reference CRS

Optional

CRS

[crs]

CRS to be used instead of the reference layer’s

Override reference cell size X

Optional

CELL_SIZE_X

[number]

Cell size in X direction to be used instead of the reference layer’s

Override reference cell size Y

Optional

CELL_SIZE_Y

[number]

Cell size in Y direction to be used instead of the reference layer’s

Override reference grid offset X

Optional

GRID_OFFSET_X

[number]

Offset in X direction to apply to cells grid

Override reference grid offset Y

Optional

GRID_OFFSET_Y

[number]

Offset in Y direction to apply to cells grid

Clip to extent

Optional

EXTENT

[extent]

Specify the extent of the output raster layer. It will internally be extended to a multiple of the tile size.

Available methods are:

  • Calculate from layer…: uses extent of a layer loaded in the current project

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Aligned raster

OUTPUT

[raster]

output raster with pixels resampled

Outputs

Label

Name

Type

Description

Aligned raster

OUTPUT

[raster]

output raster with pixels resampled

Python code

Algorithm ID: native:alignraster

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

28.1.18.2. Align rasters

Aligns rasters by resampling them to the same cell size and reprojecting to the same CRS as a reference raster.

Warning

This algorithm is NOT available in the Model Designer context.

Parameters

Label

Name

Type

Description

Input layers

INPUT

[raster] [list]

List of input raster layers with resampling options associated (filled as a QgsProcessingParameterAlignRasterLayers item):

Input layer [string] (inputFile)

Full path of the input layer to align

Output file [string] (outputFile)

Full path of the corresponding aligned output layer

Resampling method [enumeration] (resampleMethod)

Method to use for input layer resampling. Available options are:

  • 0 — Nearest Neighbour

  • 1 — Bilinear (2x2 kernel)

  • 2 — Cubic (4x4 kernel)

  • 3 — Cubic B-Spline (4x4 kernel)

  • 4 — Lanczos (6x6 kernel)

  • 5 — Average

  • 6 — Mode

  • 7 — Maximum

  • 8 — Minimum

  • 9 — Median

  • 10 — First quartile (Q1)

  • 11 — Third quartile (Q3)

Rescale values according to the cell size [boolean] (rescale)

Reference layer

REFERENCE_LAYER

[raster]

A raster layer that will be used to fetch extent, cell size and CRS that will be applied to input layers.

Override reference CRS

Optional

CRS

[crs]

CRS to be used instead of the reference layer’s

Override reference cell size X

Optional

CELL_SIZE_X

[number]

Cell size in X direction to be used instead of the reference layer’s

Override reference cell size Y

Optional

CELL_SIZE_Y

[number]

Cell size in Y direction to be used instead of the reference layer’s

Override reference grid offset X

Optional

GRID_OFFSET_X

[number]

Offset in X direction to apply to cells grid

Override reference grid offset Y

Optional

GRID_OFFSET_Y

[number]

Offset in Y direction to apply to cells grid

Clip to extent

Optional

EXTENT

[extent]

Specify the extent of the output raster layer. It will internally be extended to a multiple of the tile size.

Available methods are:

  • Calculate from layer…: uses extent of a layer loaded in the current project

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Outputs

Label

Name

Type

Description

Aligned rasters

OUTPUT_LAYERS

[raster] [list]

output rasters with pixels resampled

Python code

Algorithm ID: native:alignrasters

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

28.1.18.3. Convert map to raster

Creates a raster image of map canvas content.

A map theme can be selected to render a predetermined set of layers with a defined style for each layer.

Alternatively, a single layer can be selected if no map theme is set.

If neither map theme nor layer is set, the current map content will be rendered. The minimum extent entered will internally be extended to be a multiple of the tile size.

Parameters

Label

Name

Type

Description

Minimum extent to render (xmin, xmax, ymin, ymax)

EXTENT

[extent]

Specify the extent of the output raster layer. It will internally be extended to a multiple of the tile size.

Available methods are:

  • Calculate from layer…: uses extent of a layer loaded in the current project

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Tile size

TILE_SIZE

[number]

Default: 1024

Size of the tile of the output raster layer. Minimum value: 64.

Map units per pixel

MAP_UNITS_PER_PIXEL

[number]

Default: 100.0

Pixel size (in map units). Minimum value: 0.0

Make background transparent

MAKE_BACKGROUND_TRANSPARENT

[boolean]

Default: False

Allows exporting the map with a transparent background. Outputs an RGBA (instead of RGB) image if set to True.

Map theme to render

Optional

MAP_THEME

[enumeration]

Use an existing map theme for the rendering.

Single layer to render

Optional

LAYER

[enumeration]

Choose a single layer for the rendering

Output layer

OUTPUT

[raster]

Default: [Save to temporary file]

Specification of the output raster. One of:

  • Save to a Temporary File

  • Save to File…

Outputs

Label

Name

Type

Description

Output layer

OUTPUT

[raster]

Output raster layer

Python code

Algorithm ID: native:rasterize

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

28.1.18.4. Fill NoData cells

Resets the NoData values in the input raster to a chosen value, resulting in raster dataset with no NoData pixels.

The algorithm respects the input raster data type, e.g. a floating point fill value will be truncated when applied to an integer raster.

../../../../_images/fill_nodata.png

Fig. 28.39 Filling NoData values (in grey) of a raster

Parameters

Label

Name

Type

Description

Input raster

INPUT

[raster]

The raster to process.

Band number

BAND

[number]

Default: 1

The band of the raster

Fill value

FILL_VALUE

[number]

Default: 1.0

Set the value to use for the NoData pixels

Output raster

OUTPUT

[raster]

Default: [Save to temporary file]

Specification of the output raster. One of:

  • Save to a Temporary File

  • Save to File…

Outputs

Label

Name

Type

Description

Output raster

OUTPUT

[raster]

The output raster layer with filled data cells.

Python code

Algorithm ID: native:fillnodata

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

28.1.18.5. Generate XYZ tiles (Directory)

Generates raster “XYZ” tiles using the current QGIS project as individual images to a directory structure.

Optionally, a Leaflet HTML output file using the generated tiles as a map layer could be created.

Parameters

Basic parameters

Label

Name

Type

Description

Extent (xmin, xmax, ymin, ymax)

EXTENT

[extent]

Specify the extent of the tiles. It will internally be extended to a multiple of the tile size.

Available methods are:

  • Calculate from layer…: uses extent of a layer loaded in the current project

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Minimum zoom

ZOOM_MIN

[number]

Default: 12

Minimum 0, maximum 25.

Maximum zoom

ZOOM_MAX

[number]

Default: 12

Minimum 0, maximum 25.

DPI

DPI

[number]

Default: 96

Minimum 48, maximum 600.

Background color

Optional

BACKGROUND_COLOR

[color]

Default: QColor(0, 0, 0, 0)

Choose the background color for the tiles

Enable antialiasing

ANTIALIAS

[boolean]

Default: True

Determines if antialiasing should be enabled

Tile format

TILE_FORMAT

[enumeration]

Default: 0

One of:

  • 0 — PNG

  • 1 — JPG

Quality (JPG only)

Optional

QUALITY

[number]

Default: 75

Minimum 1, maximum 100.

Metatile size

Optional

METATILESIZE

[number]

Default: 4

Specify a custom metatile size when generating XYZ tiles. Larger values may speed up the rendering of tiles and provide better labelling (fewer gaps without labels) at the expense of using more memory. Minimum 1, maximum 20.

Tile width

Optional

TILE_WIDTH

[number]

Default: 256

Minimum 1, maximum 4096.

Tile height

Optional

TILE_HEIGHT

[number]

Default: 256

Minimum 1, maximum 4096.

Use inverted tile Y axis (TMS conventions)

Optional

TMS_CONVENTION

[boolean]

Default: False

Output directory

Optional

OUTPUT_DIRECTORY

[folder]

Default: [Save to temporary folder]

Specification of the output directory (for the tiles). One of:

  • Skip Output

  • Save to a Temporary Directory

  • Save to Directory

Output html (Leaflet)

Optional

OUTPUT_HTML

[html]

Default: [Save to temporary file]

Specification of the output HTML file. One of:

  • Skip Output

  • Save to a Temporary File

  • Save to File…

Advanced parameters

Label

Name

Type

Description

Leaflet HTML output title

Optional

HTML_TITLE

[string]

Default: Not set

HTML <title>-tag used for the Leaflet HTML output file.

Leaflet HTML output attribution

Optional

HTML_ATTRIBUTION

[string]

Default: Not set

Custom map attribution used for the Leaflet HTML output file. HTML links are possible.

Include OpenStreetMap basemap in Leaflet HTML output

Optional

HTML_OSM

[boolean]

Default: False

An OpenStreetMap basemap layer (source: https://tile.openstreetmap.org) is included in the Leaflet HTML output file. Proper map attribution is added automatically.

Outputs

Label

Name

Type

Description

Output directory

OUTPUT_DIRECTORY

[folder]

Output directory (for the tiles)

Output html (Leaflet)

OUTPUT_HTML

[html]

The output HTML (Leaflet) file

Python code

Algorithm ID: qgis:tilesxyzdirectory

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.

28.1.18.6. Generate XYZ tiles (MBTiles)

Generates raster “XYZ” tiles using the current QGIS project as a single file in the “MBTiles” format.

Parameters

Label

Name

Type

Description

Extent (xmin, xmax, ymin, ymax)

EXTENT

[extent]

Specify the extent of the tiles. It will internally be extended to a multiple of the tile size.

Available methods are:

  • Calculate from layer…: uses extent of a layer loaded in the current project

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Minimum zoom

ZOOM_MIN

[number]

Default: 12

Minimum 0, maximum 25.

Maximum zoom

ZOOM_MAX

[number]

Default: 12

Minimum 0, maximum 25.

DPI

DPI

[number]

Default: 96

Minimum 48, maximum 600.

Background color

Optional

BACKGROUND_COLOR

[color]

Default: QColor(0, 0, 0, 0)

Choose the background color for the tiles

Enable antialiasing

ANTIALIAS

[boolean]

Default: True

Determines if antialiasing should be enabled

Tile format

TILE_FORMAT

[enumeration]

Default: 0

One of:

  • 0 — PNG

  • 1 — JPG

Quality (JPG only)

Optional

QUALITY

[number]

Default: 75

Minimum 1, maximum 100.

Metatile size

Optional

METATILESIZE

[number]

Default: 4

Specify a custom metatile size when generating XYZ tiles. Larger values may speed up the rendering of tiles and provide better labelling (fewer gaps without labels) at the expense of using more memory. Minimum 1, maximum 20.

Output file (for MBTiles)

OUTPUT_FILE

[file]

Default: [Save to temporary file]

Specification of the output file. One of:

  • Skip Output

  • Save to a Temporary File

  • Save to File…

Outputs

Label

Name

Type

Description

Output file (for MBTiles)

OUTPUT_FILE

[file]

The output file.

Python code

Algorithm ID: qgis:tilesxyzmbtiles

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.