28.2.4. Raster miscellaneous
28.2.4.1. 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:
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[raster] |
Input raster layer |
Remove all existing overviews |
|
[boolean] Default: False |
Removes existing overviews from the raster. By default these are not removed. |
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Overview 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 |
|
[enumeration] Default: 0 |
Calculates the overviews with a defined resampling method. Possible resampling methods are:
|
Overviews format Optional |
|
[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:
|
Additional command-line parameters Optional |
|
[string] Default: None |
Add extra GDAL command line options |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Pyramidized |
|
[raster] |
Output raster layer with overviews |
Python code
Algorithm ID: gdal:overviews
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.
28.2.4.2. 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:
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layers |
|
[raster] [list] |
GDAL-supported raster layers. |
Resolution |
|
[enumeration] Default: 0 |
The output resolution of the mosaic. By default the average resolution of the raster files will be chosen. Options:
|
Place each input file into a separate band |
|
[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 |
|
[boolean] Default: False |
Allows that the output bands have different projections derived from the projection of the input raster layers. |
Virtual |
|
[raster] Default: |
Specification of the output raster layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Add alpha mask band to VRT when source raster has none |
|
[boolean] Default: False |
Adds an alpha mask band to the VRT when the source raster has none. |
Override projection for the output file Optional |
|
[crs] Default: None |
Overrides the projection for the output file. No reprojection is done. |
Resampling algorithm |
|
[enumeration] Default: 0 |
The resampling algorithm to use. Options:
|
NoData value(s) for input bands (space separated) Optional |
|
[string] Default: None |
Space separated NoData value(s) for input band(s) |
Additional command-line parameters |
|
[string] Default: None |
Add extra GDAL command line options |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Virtual |
|
[raster] |
Output raster layer |
Python code
Algorithm ID: gdal:buildvirtualraster
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.
28.2.4.3. 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 |
|
[raster] |
GDAL-supported raster layer. |
Tile cutting profile |
|
[enumeration] Default: 0 |
One of:
|
Zoom levels to render Optional |
|
[string] Default: ‘’ |
|
Web viewer to generate |
|
[enumerate] Default: 0 |
One of:
|
Title of the map Optional |
|
[string] Default: ‘’ |
|
Copyright of the map |
|
[string] Default: ‘’ |
|
Output directory |
|
[folder] Default: |
Specify the output folder for the tiles. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Resampling method |
|
[enumeration] Default: 0 |
The resampling algorithm to use. Options:
|
The spatial reference system used for the source input data Optional |
|
[crs] Default: None |
|
Transparency value to assign to the input data Optional |
|
[number] Default: 0.0 |
|
URL address where the generated tiles are going to be published Optional |
|
[string] Default: ‘’ |
|
Google Maps API key (http://code.google.com/apis/maps/signup.html) Optional |
|
[string] Default: ‘’ |
Your Google maps API key. |
Bing Maps API key (https://www.bingmapsportal.com/) Optional |
|
[string] Default: ‘’ |
Your Bing maps API key. |
Generate only missing files |
|
[boolean] Default: False |
|
Generate KML for Google Earth |
|
[boolean] Default: False |
|
Avoid automatic generation of KML files for EPSG:4326 |
|
[boolean] Default: False |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Output directory |
|
[folder] |
The output folder (for the tiles) |
Python code
Algorithm ID: gdal:gdal2tiles
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.
28.2.4.4. 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:
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layers |
|
[raster] [list] |
Input raster layers |
Grab pseudocolor table from first layer |
|
[boolean] Default: False |
The pseudocolor table from the first layer will be used for the coloring |
Place each input file into a separate band |
|
[boolean] Default: False |
Place each input file into a separate band |
Output data type |
|
[enumeration] Default: 5 |
Defines the format of the output raster file. Options:
Available options depend on the GDAL version built with QGIS (see menu) |
Merged |
|
[raster] Default: |
Specification of the output raster layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input pixel value to treat as “NoData” Optional |
|
[number] Default: None |
Ignores pixels from files being merged in with this pixel value |
Assign specified “NoData” value to output Optional |
|
[number] Default: None |
Assigns the specified NoData value to output bands. |
Additional creation options Optional |
|
[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 GDAL driver options section). Batch Process and Model Designer: separate multiple options with a pipe
character ( |
Additional command-line parameters |
|
[string] Default: None |
Add extra GDAL command line options |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Merged |
|
[raster] |
Output raster layer |
Python code
Algorithm ID: gdal:merge
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.
28.2.4.5. 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 |
|
[raster] |
Input (spectral) raster layer |
Panchromatic dataset |
|
[raster] |
Input (panchromatic) raster layer |
Output |
|
[raster] Default: |
Specify the output (sharpened) raster layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Resampling algorithm |
|
[enumeration] Default: 2 |
The resampling algorithm to use. Options:
|
Additional creation options Optional |
|
[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 GDAL driver options section). Batch Process and Model Designer: separate multiple options with a pipe
character ( |
Additional command-line parameters Optional |
|
[string] Default: None |
Add extra GDAL command line options |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Output |
|
[raster] |
Output (sharpened) raster layer |
Python code
Algorithm ID: gdal:pansharp
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.
28.2.4.6. 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.
See also
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer A |
|
[raster] |
First input raster layer (mandatory) |
Number of raster band for A |
|
[raster band] |
Band for input layer A (mandatory) |
Input layer B Optional |
|
[raster] Default: None |
Second input raster layer |
Number of raster band for B Optional |
|
[raster band] |
Band for input layer B |
Input layer C Optional |
|
[raster] Default: None |
Third input raster layer |
Number of raster band for C Optional |
|
[raster band] |
Band for input layer C |
Input layer D Optional |
|
[raster] Default: None |
Fourth input raster layer |
Number of raster band for D Optional |
|
[raster band] |
Band for input layer D |
Input layer E Optional |
|
[raster] Default: None |
Fifth input raster layer |
Number of raster band for E Optional |
|
[raster band] |
Band for input layer E |
Input layer F Optional |
|
[raster] |
Sixth input raster layer |
Number of raster band for F Optional |
|
[raster band] Default: None |
Band for input layer F |
Calculation in gdalnumeric syntax using +-/* or any numpy array functions (i.e. logical_and()) |
|
[string] Default: ‘’ |
The calculation formula. Examples:
|
Set output NoData value Optional |
|
[number] Default: None |
Value to use for NoData |
Handling of extent differences |
|
[enumeration] Default: 0 |
Determines how to handle rasters with different extents. Only available with GDAL 3.3+. Supported options are:
|
Output extent Optional |
|
[extent] |
Custom extent of the output raster. Only available with GDAL 3.3+. Available methods are:
|
Output raster type |
|
[enumeration] Default: 5 |
Defines the data type of the output raster file. Options:
Available options depend on the GDAL version built with QGIS (see menu) |
Calculated |
|
[raster] Default: |
Specify the output (calculated) raster layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[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 GDAL driver options section). Batch Process and Model Designer: separate multiple options with a pipe
character ( |
Additional command-line parameters Optional |
|
[string] Default: ‘’ |
Add extra GDAL command line options |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Calculated |
|
[raster] |
Output (calculated) raster layer |
Python code
Algorithm ID: gdal:rastercalculator
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.
28.2.4.7. 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:
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[raster] |
Input raster layer |
Force computation of the actual min/max values for each band |
|
[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) |
|
[boolean] Default: False |
Reads and displays image statistics. Forces computation if no statistics are stored in an image. |
Suppress GCP info |
|
[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 |
|
[boolean] Default: False |
Suppresses metadata printing. Some datasets may contain a lot of metadata strings. |
Layer information |
|
[html] Default: |
Specify the HTML file for output. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional command-line parameters Optional |
|
[string] Default: None |
Add extra GDAL command line options |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Layer information |
|
[html] |
The HTML file containing information about the input raster layer |
Python code
Algorithm ID: gdal:gdalinfo
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.
28.2.4.8. 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 |
|
[raster] [list] |
The input raster files |
Tile width |
|
[number] Default: 256 |
Width of the tiles in pixels (minimum 0) |
Tile height |
|
[number] Default: 256 |
Height of the tiles in pixels (minimum 0) |
Overlap in pixels between consecutive tiles |
|
[number] Default: 0 |
|
Number of pyramid levels to build |
|
[number] Default: 1 |
Minimum: 0 |
Output directory |
|
[folder] Default: |
Specify the output folder for the tiles. One of:
|
CSV file containing the tile(s) georeferencing information |
|
[file] Default: |
Specify the output file for the tiles. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Source coordinate reference system Optional |
|
[crs] Default: None |
|
Resampling method |
|
[enumeration] Default: 0 |
The resampling algorithm to use. Options:
|
Column delimiter used in the CSV file Optional |
|
[string] Default: ‘;’ |
Delimiter to use in the CSV file containing the tile(s) georeferencing information |
Additional creation options Optional |
|
[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 GDAL driver options section). Batch Process and Model Designer: separate multiple options with a pipe
character ( |
Additional command-line parameters Optional |
|
[string] Default: ‘’ |
Add extra GDAL command line options |
Output data type |
|
[enumeration] Default: 5 |
Defines the format of the output raster file. Options:
Available options depend on the GDAL version built with QGIS (see menu) |
Build only the pyramids |
|
[boolean] Default: False |
|
Use separate directory for each tile row |
|
[boolean] Default: False |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Output directory |
|
[folder] |
The output folder for the tiles. |
CSV file containing the tile(s) georeferencing information |
|
[file] |
The CSV file with georeferencing information for the tiles. |
Python code
Algorithm ID: gdal:retile
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.
28.2.4.9. 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:
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input files |
|
[raster] [list] |
The input raster files. Can be multiple files. |
Field name to hold the file path to the indexed rasters |
|
[string] Default: ‘location’ |
The output field name to hold the file path/location to the indexed rasters. |
Store absolute path to the indexed rasters |
|
[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 |
|
[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 |
|
[vector: polygon] Default: |
Specify the polygon vector layer to write the index to. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Transform geometries to the given CRS Optional |
|
[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 |
|
[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 |
|
[enumeration] Default: 0 |
Format for the CRS. One of:
|
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Tile index |
|
[vector: polygon] |
The polygon vector layer with the tile index. |
Python code
Algorithm ID: gdal:tileindex
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.
28.2.4.10. 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 |
|
[raster] |
Input elevation raster layer |
Band number |
|
[raster band] Default: 1 |
The number of the band to use as elevation |
Observer location |
|
[point] |
The location of the observer |
Observer height |
|
[number] Default: 1.0 |
The altitude of the observer, in the DEM units |
Target height |
|
[number] Default: 1.0 |
The altitude of the target element, in the DEM units |
Maximum distance from observer to compute visibility |
|
[number] Default: 100.0 |
Maximum distance from observer to compute visibility, in the DEM units |
Output |
|
[raster] Default: |
Output raster layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[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 GDAL driver options section). Batch Process and Model Designer: separate multiple options with a pipe
character ( |
Additional command-line parameters |
|
[string] Default: None |
Add extra GDAL command line options |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Output |
|
[raster] |
The raster layer displaying the viewshed. |
Python code
Algorithm ID: gdal:viewshed
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.