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Raster miscellaneous

.. only:: html

   .. contents::
      :local:
      :depth: 1

Build overviews (pyramids)

To speed up rendering time of raster layers overviews (pyramids) can be created. Overviews are lower resolution copies of the data which QGIS uses depending of the level of zoom.

This algorithm is derived from the GDAL addo utility.

Default menu: :menuselection:`Raster --> Miscellaneous`

Parameters

Basic parameters

Label Name Type Description
Input layer INPUT [raster] Input raster layer
Remove all existing overviews CLEAN

[boolean]

Default: False

 Removes existing overviews from the raster. By default these are not removed.

Advanced parameters

Label Name Type Description
Overview levels LEVELS

[string]

Default: '2 4 8 16'

 Defines the number of overview levels calculated by the original resolution of the input raster layer. By default 4 levels will be taken into consideration.

Resampling method

Optional

 RESAMPLING

[enumeration]

Default: 0

Calculates the overviews with a defined resampling method. Possible resampling methods are:

  • 0 -- Nearest Neighbour (nearest)
  • 1 -- Average (average)
  • 2 -- Gaussian (gauss)
  • 3 -- Cubic (4x4 kernel) (cubic)
  • 4 -- Cubic B-Spline (4x4 kernel) (cubicspline)
  • 5 -- Lanczos (6x6 kernel) (lanczos)
  • 6 -- Average MP (average_mp)
  • 7 -- Average in Mag/Phase Space (average_magphase)
  • 8 -- Mode (mode)

Overviews format

Optional

 FORMAT

[enumeration]

Default: 0

The overviews can be stored internally, or externally as GTiff or ERDAS Imagine file. By default the overviews are stored in the output raster. Possible formats methods are:

  • 0 -- Internal (if possible)
  • 1 -- External (GTiff .ovr)
  • 2 -- External (ERDAS Imagine .aux)

Additional command-line parameters

Optional

 EXTRA

[string]

Default: Not set

 Add extra GDAL command line options

Outputs

Label Name Type Description
Pyramidized OUTPUT [raster] Output raster layer with overviews

Python code

Algorithm ID: gdal:overviews

Build virtual raster

Builds a VRT (Virtual Dataset) that is a mosaic of the list of input GDAL-supported rasters. With a mosaic you can merge several raster files.

This algorithm is derived from the GDAL buildvrt utility.

Default menu: :menuselection:`Raster --> Miscellaneous`

Parameters

Basic parameters

Label Name Type Description
Input layers INPUT [raster] [list] GDAL-supported raster layers.
Resolution RESOLUTION

[enumeration]

Default: 0

The output resolution of the mosaic. By default the average resolution of the raster files will be chosen.

Options:

  • 0 --- Average (average)
  • 1 --- Highest (highest)
  • 2 --- Lowest (lowest)
Place each input file into a separate band SEPARATE

[boolean]

Default: False

 With 'True' you can define that each raster file goes into a separated stacked band in the VRT band.
Allow projection difference PROJ_DIFFERENCE

[boolean]

Default: False

 Allows that the output bands have different projections derived from the projection of the input raster layers.
Virtual OUTPUT

[raster]

Default: [Save to temporary file]

 Specification of the output raster layer. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description
Add alpha mask band to VRT when source raster has none ADD_ALPHA

[boolean]

Default: False

 Adds an alpha mask band to the VRT when the source raster has none.

Override projection for the output file

Optional

 ASSIGN_CRS

[crs]

Default: Not set

 Overrides the projection for the output file. No reprojection is done.
Resampling algorithm RESAMPLING

[enumeration]

Default: 0

The resampling algorithm to use. Options:

  • 0 --- Nearest Neighbour (nearest)
  • 1 --- Bilinear (2x2 kernel) (bilinear)
  • 2 --- Cubic (4x4 kernel) (cubic)
  • 3 --- Cubic B-Spline (4x4 kernel) (cubicspline)
  • 4 --- Lanczos (6x6 kernel) (lanczos)
  • 5 --- Average (average)
  • 6 --- Mode (mode)

NoData value(s) for input bands (space separated)

Optional

 SRC_NODATA

[string]

Default: Not set

 Space separated NoData value(s) for input band(s)
Additional command-line parameters EXTRA

[string]

Default: Not set

 Add extra GDAL command line options

Outputs

Label Name Type Description
Virtual OUTPUT [raster] Output raster layer

Python code

Algorithm ID: gdal:buildvirtualraster

gdal2tiles

Generates a directory with small tiles and metadata, following the OSGeo Tile Map Service Specification. See also the OpenGIS Web Map Tile Service Implementation Standard. Simple web pages with viewers based on Google Maps, OpenLayers and Leaflet are generated as well. To explore your maps on-line in the web browser, you only need to upload the generated directory onto a web server.

This algorithm also creates the necessary metadata for Google Earth (KML SuperOverlay), in case the supplied map uses EPSG:4326 projection.

ESRI world files and embedded georeferencing is used during tile generation, but you can publish a picture without proper georeferencing too.

This algorithm is derived from the GDAL gdal2tiles utility.

Parameters

Basic parameters

Label Name Type Description
Input layer INPUT [raster] GDAL-supported raster layer.
Tile cutting profile PROFILE

[enumeration]

Default: 0

One of:

  • 0 --- Mercator (mercator)
  • 1 --- Geodetic (geodetic)
  • 2 --- Raster (raster)

Zoom levels to render

Optional

 ZOOM

[string]

Default: ''

  
Web viewer to generate VIEWER

[enumeration]

Default: 0

One of:

  • 0 --- All (all)
  • 1 --- GoogleMaps (google)
  • 2 --- OpenLayers (openlayers)
  • 3 --- Leaflet (leaflet)
  • 4 --- None (none)

Title of the map

Optional

 TITLE

[string]

Default: ''

  
Copyright of the map COPYRIGHT

[string]

Default: ''

  
Output directory OUTPUT

[folder]

Default: [Save to temporary folder]

 Specify the output folder for the tiles. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description
Resampling method RESAMPLING

[enumeration]

Default: 0

The resampling algorithm to use. Options:

  • 0 --- Average (average)
  • 1 --- Nearest Neighbour (near)
  • 2 --- Bilinear (2x2 kernel) (bilinear)
  • 3 --- Cubic (4x4 kernel) (cubic)
  • 4 --- Cubic B-Spline (4x4 kernel) (cubicspline)
  • 5 --- Lanczos (6x6 kernel) (lanczos)
  • 6 --- Antialias (antialias)

The spatial reference system used for the source input data

Optional

 SOURCE_CRS

[crs]

Default: Not set

  

Transparency value to assign to the input data

Optional

 NODATA

[numeric: double]

Default: 0.0

  

URL address where the generated tiles are going to be published

Optional

 URL

[string]

Default: ''

  

Google Maps API key (http://code.google.com/apis/maps/signup.html)

Optional

 GOOGLE_KEY

[string]

Default: ''

 Your Google maps API key.

Bing Maps API key (https://www.bingmapsportal.com/)

Optional

 BING_KEY

[string]

Default: ''

 Your Bing maps API key.
Generate only missing files RESUME

[boolean]

Default: False

  
Generate KML for Google Earth KML

[boolean]

Default: False

  
Avoid automatic generation of KML files for EPSG:4326 NO_KML

[boolean]

Default: False

  

Outputs

Label Name Type Description
Output directory OUTPUT [folder] The output folder (for the tiles)

Python code

Algorithm ID: gdal:gdal2tiles

Merge

Merges raster files in a simple way. Here you can use a pseudocolor table from an input raster and define the output raster type. All the images must be in the same coordinate system.

This algorithm is derived from the GDAL merge utility.

Default menu: :menuselection:`Raster --> Miscellaneous`

Parameters

Basic parameters

Label Name Type Description
Input layers INPUT [raster] [list] Input raster layers
Grab pseudocolor table from first layer PCT

[boolean]

Default: False

 The pseudocolor table from the first layer will be used for the coloring
Place each input file into a separate band SEPARATE

[boolean]

Default: False

 Place each input file into a separate band
Output data type DATA_TYPE

[enumeration]

Default: 5

 Defines the format of the output raster file. Options:
Merged OUTPUT

[raster]

Default: [Save to temporary file]

 Specification of the output raster layer. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description

Input pixel value to treat as "NoData"

Optional

 NODATA_INPUT

[numeric: double]

Default: Not set

 Ignores pixels from files being merged in with this pixel value

Assign specified "NoData" value to output

Optional

 NODATA_OUTPUT

[numeric: double]

Default: Not set

 Assigns the specified NoData value to output bands.

Additional creation options

Optional

 CREATION_OPTIONS (for QGIS <= 3.42, this was OPTIONS)

[string]

Default: ''

For adding one or more creation options that control the raster to be created (colors, block size, file compression...). For convenience, you can rely on predefined profiles (see :ref:`GDAL driver options section <gdal_createoptions>`).

Batch Process and Model Designer: separate multiple options with a pipe character (|).
Additional command-line parameters EXTRA

[string]

Default: Not set

 Add extra GDAL command line options

Outputs

Label Name Type Description
Merged OUTPUT [raster] Output raster layer

Python code

Algorithm ID: gdal:merge

Pansharpening

Performs a pan-sharpening operation. It can create a "classic" output dataset (such as GeoTIFF), or a VRT dataset describing the pan-sharpening operation.

See GDAL Pansharpen.

Parameters

Basic parameters

Label Name Type Description
Spectral dataset SPECTRAL [raster] Input (spectral) raster layer
Panchromatic dataset PANCHROMATIC [raster] Input (panchromatic) raster layer
Output OUTPUT

[raster]

Default: [Save to temporary file]

 Specify the output (sharpened) raster layer. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description
Resampling algorithm RESAMPLING

[enumeration]

Default: 2

The resampling algorithm to use. Options:

  • 0 --- Nearest Neighbour (nearest)
  • 1 --- Bilinear (2x2 kernel) (bilinear)
  • 2 --- Cubic (4x4 kernel) (cubic)
  • 3 --- Cubic B-Spline (4x4 kernel) (cubicspline)
  • 4 --- Lanczos (6x6 kernel) (lanczos)
  • 5 --- Average (average)

Additional creation options

Optional

 CREATION_OPTIONS (for QGIS <= 3.42, this was OPTIONS)

[string]

Default: ''

For adding one or more creation options that control the raster to be created (colors, block size, file compression...). For convenience, you can rely on predefined profiles (see :ref:`GDAL driver options section <gdal_createoptions>`).

Batch Process and Model Designer: separate multiple options with a pipe character (|).

Additional command-line parameters

Optional

 EXTRA

[string]

Default: Not set

 Add extra GDAL command line options

Outputs

Label Name Type Description
Output OUTPUT [raster] Output (sharpened) raster layer

Python code

Algorithm ID: gdal:pansharp

Raster calculator

Command line raster calculator with numpy syntax. Use any basic arithmetic supported by numpy arrays, such as +, -, *, and / along with logical operators, such as >. Note that all input rasters must have the same dimensions, but no projection checking is performed.

See the GDAL Raster Calculator utility docs.

.. seealso:: :ref:`qgisrastercalc`, :ref:`qgisvirtualrastercalc`

Parameters

Basic parameters

Label Name Type Description
Input layer A INPUT_A [raster] First input raster layer (mandatory)
Number of raster band for A BAND_A [raster band] Band for input layer A (mandatory)

Input layer B

Optional

 INPUT_B

[raster]

Default: Not set

 Second input raster layer

Number of raster band for B

Optional

 BAND_B [raster band] Band for input layer B

Input layer C

Optional

 INPUT_C

[raster]

Default: Not set

 Third input raster layer

Number of raster band for C

Optional

 BAND_C [raster band] Band for input layer C

Input layer D

Optional

 INPUT_D

[raster]

Default: Not set

 Fourth input raster layer

Number of raster band for D

Optional

 BAND_D [raster band] Band for input layer D

Input layer E

Optional

 INPUT_E

[raster]

Default: Not set

 Fifth input raster layer

Number of raster band for E

Optional

 BAND_E [raster band] Band for input layer E

Input layer F

Optional

 INPUT_F [raster] Sixth input raster layer

Number of raster band for F

Optional

 BAND_F

[raster band]

Default: Not set

 Band for input layer F
Calculation in gdalnumeric syntax using +-/* or any numpy array functions (i.e. logical_and()) FORMULA

[string]

Default: ''

The calculation formula. Examples:

  • A*(A>0) --- outputs the value of the raster A if the value of A is greater than 0. If not, outputs 0.
  • A*(A>0 and A>B)--- outputs the value of A if that value is bigger than 0 and bigger than the value of B. If not, outputs 0.
  • A*logical_or(A<=177,A>=185) --- outputs the value of A if A <= 177 or A >= 185. If not, outputs 0.
  • sqrt(A*A+B*B) --- Outputs the square root of the sum of the value of A squared and the value of B squared.

Set output NoData value

Optional

 NO_DATA

[numeric: double]

Default: Not set

 Value to use for NoData

Handling of extent differences

Added in 3.34

 EXTENT_OPT

[enumeration]

Default: 0

Determines how to handle rasters with different extents. Supported options are:

  • 0 --- Ignore
  • 1 --- Fail
  • 2 --- Union
  • 3 --- Intersect

Attention!

Using this parameter requires QGIS installed with GDAL >= 3.3 (see :menuselection:`Help --> About` menu).

Output extent

Optional

 INPUT [extent]

Custom extent of the output raster.

Attention!

Using this parameter requires QGIS installed with GDAL >= 3.3 (see :menuselection:`Help --> About` menu).
Output raster type RTYPE

[enumeration]

Default: 5

 Defines the data type of the output raster file. Options:
Calculated OUTPUT

[raster]

Default: [Save to temporary file]

 Specify the output (calculated) raster layer. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description

Additional creation options

Optional

 CREATION_OPTIONS (for QGIS <= 3.42, this was OPTIONS)

[string]

Default: ''

For adding one or more creation options that control the raster to be created (colors, block size, file compression...). For convenience, you can rely on predefined profiles (see :ref:`GDAL driver options section <gdal_createoptions>`).

Batch Process and Model Designer: separate multiple options with a pipe character (|).

Additional command-line parameters

Optional

 EXTRA

[string]

Default: ''

 Add extra GDAL command line options

Outputs

Label Name Type Description
Calculated OUTPUT [raster] Output (calculated) raster layer

Python code

Algorithm ID: gdal:rastercalculator

Raster information

The gdalinfo program lists various information about a GDAL supported raster dataset.

This algorithm is derived from the GDAL info utility.

Default menu: :menuselection:`Raster --> Miscellaneous`

Parameters

Basic parameters

Label Name Type Description
Input layer INPUT [raster] Input raster layer
Force computation of the actual min/max values for each band MIN_MAX

[boolean]

Default: False

 Forces computation of the actual min/max values for each band in the dataset
Read and display image statistics (force computation if necessary) STATS

[boolean]

Default: False

 Reads and displays image statistics. Forces computation if no statistics are stored in an image.
Suppress GCP info NO_GCP

[boolean]

Default: False

 Suppresses ground control points list printing. It may be useful for datasets with huge amount of GCPs, such as L1B AVHRR or HDF4 MODIS which contain thousands of them.
Suppress metadata info NO_METADATA

[boolean]

Default: False

 Suppresses metadata printing. Some datasets may contain a lot of metadata strings.
Layer information OUTPUT

[html]

Default: [Save to temporary file]

 Specify the HTML file for output. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description

Additional command-line parameters

Optional

 EXTRA

[string]

Default: Not set

 Add extra GDAL command line options

Outputs

Label Name Type Description
Layer information OUTPUT [html] The HTML file containing information about the input raster layer

Python code

Algorithm ID: gdal:gdalinfo

Retile

Retiles a set of input tiles. All the input tiles must be georeferenced in the same coordinate system and have a matching number of bands. Optionally pyramid levels are generated.

This algorithm is derived from the GDAL Retile utility.

Parameters

Basic parameters

Label Name Type Description
Input files INPUT [raster] [list] The input raster files
Tile width TILE_SIZE_X

[numeric: integer]

Default: 256

 Width of the tiles in pixels (minimum 0)
Tile height TILE_SIZE_Y

[numeric: integer]

Default: 256

 Height of the tiles in pixels (minimum 0)
Overlap in pixels between consecutive tiles OVERLAP

[numeric: integer]

Default: 0

  
Number of pyramid levels to build LEVELS

[numeric: integer]

Default: 1

 Minimum: 0
Output directory OUTPUT

[folder]

Default: [Save to temporary folder]

 Specify the output folder for the tiles. :ref:`One of <output_parameter_widget>`:
CSV file containing the tile(s) georeferencing information OUTPUT_CSV

[file]

Default: [Skip output]

 Specify the output file for the tiles. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description

Source coordinate reference system

Optional

 SOURCE_CRS

[crs]

Default: Not set

  
Resampling method RESAMPLING

[enumeration]

Default: 0

The resampling algorithm to use. Options:

  • 0 --- Nearest Neighbour (nearest)
  • 1 --- Bilinear (2x2 kernel) (bilinear)
  • 2 --- Cubic (4x4 kernel) (cubic)
  • 3 --- Cubic B-Spline (4x4 kernel) (cubicspline)
  • 4 --- Lanczos (6x6 kernel) (lanczos)

Column delimiter used in the CSV file

Optional

 DELIMITER

[string]

Default: ';'

 Delimiter to use in the CSV file containing the tile(s) georeferencing information

Additional creation options

Optional

 CREATION_OPTIONS (for QGIS <= 3.42, this was OPTIONS)

[string]

Default: ''

For adding one or more creation options that control the raster to be created (colors, block size, file compression...). For convenience, you can rely on predefined profiles (see :ref:`GDAL driver options section <gdal_createoptions>`).

Batch Process and Model Designer: separate multiple options with a pipe character (|).

Additional command-line parameters

Optional

 EXTRA

[string]

Default: ''

 Add extra GDAL command line options
Output data type DATA_TYPE

[enumeration]

Default: 5

 Defines the format of the output raster file. Options:
Build only the pyramids ONLY_PYRAMIDS

[boolean]

Default: False

  
Use separate directory for each tile row DIR_FOR_ROW

[boolean]

Default: False

  

Outputs

Label Name Type Description
Output directory OUTPUT [folder] The output folder for the tiles.
CSV file containing the tile(s) georeferencing information OUTPUT_CSV [file] The CSV file with georeferencing information for the tiles.

Python code

Algorithm ID: gdal:retile

Tile index

Builds a vector layer with a record for each input raster file, an attribute containing the filename, and a polygon geometry outlining the raster. This output is suitable for use with MapServer as a raster tileindex.

This algorithm is derived from the GDAL Tile Index utility.

Default menu: :menuselection:`Raster --> Miscellaneous`

Parameters

Basic parameters

Label Name Type Description
Input files LAYERS [raster] [list] The input raster files. Can be multiple files.

Field name to hold the file path to the indexed rasters

Optional

 PATH_FIELD_NAME

[string]

Default: 'location'

 The output field name to hold the file path/location to the indexed rasters.
Store absolute path to the indexed rasters ABSOLUTE_PATH

[boolean]

Default: False

 Set whether the absolute path to the raster files is stored in the tile index file. By default the raster filenames will be put in the file exactly as they are specified in the command.
Skip files with different projection reference PROJ_DIFFERENCE

[boolean]

Default: False

 Only files with same projection as files already inserted in the tile index will be inserted. Default does not check projection and accepts all inputs.
Tile index OUTPUT

[vector: polygon]

Default: [Save to temporary file]

 Specify the polygon vector layer to write the index to. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description

Transform geometries to the given CRS

Optional

 TARGET_CRS [crs] Geometries of input files will be transformed to the specified target coordinate reference system. Default creates simple rectangular polygons in the same coordinate reference system as the input rasters.

The name of the field to store the SRS of each tile

Optional

 CRS_FIELD_NAME [string] The name of the field to store the SRS of each tile
The format in which the CRS of each tile must be written CRS_FORMAT

[enumeration]

Default: 0

Format for the CRS. One of:

  • 0 -- Auto (AUTO)
  • 1 -- Well-known text (WKT)
  • 2 -- EPSG (EPSG)
  • 3 -- Proj.4 (PROJ)

Outputs

Label Name Type Description
Tile index OUTPUT [vector: polygon] The polygon vector layer with the tile index.

Python code

Algorithm ID: gdal:tileindex

Viewshed

Calculates a viewshed raster from an input raster DEM using method defined in Wang2000 for a user defined point.

Parameters

Basic parameters

Label Name Type Description
Input layer INPUT [raster] Input elevation raster layer
Band number BAND

[raster band]

Default: 1

 The number of the band to use as elevation
Observer location OBSERVER [coordinates] The location of the observer
Observer height OBSERVER_HEIGHT

[numeric: double]

Default: 1.0

 The altitude of the observer, in the DEM units
Target height TARGET_HEIGHT

[numeric: double]

Default: 1.0

 The altitude of the target element, in the DEM units
Maximum distance from observer to compute visibility MAX_DISTANCE

[numeric: double]

Default: 100.0

 Maximum distance from observer to compute visibility, in the DEM units
Output OUTPUT

[raster]

Default: [Save to temporary file]

 Output raster layer. :ref:`One of <output_parameter_widget>`:

Advanced parameters

Label Name Type Description

Additional creation options

Optional

 CREATION_OPTIONS (for QGIS <= 3.42, this was OPTIONS)

[string]

Default: ''

For adding one or more creation options that control the raster to be created (colors, block size, file compression...). For convenience, you can rely on predefined profiles (see :ref:`GDAL driver options section <gdal_createoptions>`).

Batch Process and Model Designer: separate multiple options with a pipe character (|).
Additional command-line parameters EXTRA

[string]

Default: Not set

 Add extra GDAL command line options

Outputs

Label Name Type Description
Output OUTPUT [raster] The raster layer displaying the viewshed.

Python code

Algorithm ID: gdal:viewshed