24.2.4. Raster miscellaneous

24.2.4.1. 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: Raster ► Miscellaneous

參數

Basic parameters

Label	名稱	Type	說明
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	名稱	Type	說明
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 Convolution (cubic) 4 -- B-Spline Convolution (cubicspline) 5 -- Lanczos Windowed Sinc (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: None	Add extra GDAL command line options

輸出

Label	名稱	Type	說明
Pyramidized	OUTPUT	[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.

24.2.4.2. 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: Raster ► Miscellaneous

參數

Basic parameters

Label	名稱	Type	說明
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. 選項： 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. One of: Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
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: None	Overrides the projection for the output file. No reprojection is done.
Resampling algorithm	RESAMPLING	[enumeration] Default: 0	The resampling algorithm to be used Options: 0 --- Nearest Neighbour (nearest) 1 --- Bilinear (bilinear) 2 --- Cubic Convolution (cubic) 3 --- B-Spline Convolution (cubicspline) 4 --- Lanczos Windowed Sinc (lanczos) 5 --- Average (average) 6 --- Mode (mode)
Nodata value(s) for input bands (space separated) Optional	SRC_NODATA	[string] Default: None	Space separated Nodata value(s) for input band(s)
Additional command-line parameters	EXTRA	[string] Default: None	Add extra GDAL command line options

輸出

Label	名稱	Type	說明
Virtual	OUTPUT	[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.

24.2.4.3. 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.

參數

Basic parameters

Label	名稱	Type	說明
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	[enumerate] 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. One of: Save to a Temporary Directory Save to Directory

Advanced parameters

Label	名稱	Type	說明
Resampling method	RESAMPLING	[enumeration] Default: 0	The resampling algorithm to be used Options: 0 --- Average (average) 1 --- Nearest neighbour (near) 2 --- Bilinear (bilinear) 3 --- Cubic (cubic) 4 --- Cubic spline (cubicspline) 5 --- Lanczos Windowed sinc (lanczos) 6 --- Antialias (antialias)
The spatial reference system used for the source input data Optional	SOURCE_CRS	[crs] Default: None
Transparency value to assign to the input data Optional	NODATA	[number] 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

輸出

Label	名稱	Type	說明
Output directory	OUTPUT	[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.

24.2.4.4. 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: Raster ► Miscellaneous

參數

Basic parameters

Label	名稱	Type	說明
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: 0 --- Byte 1 --- Int16 2 --- UInt16 3 --- UInt32 4 --- Int32 5 --- Float32 6 --- Float64 7 --- CInt16 8 --- CInt32 9 --- CFloat32 10 --- CFloat64
Merged	OUTPUT	[raster] Default: [Save to temporary file]	Specification of the output raster layer. One of: Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
Input pixel value to treat as "nodata" Optional	NODATA_INPUT	[number] Default: None	Ignores pixels from files being merged in with this pixel value
Assign specified "nodata" value to output Optional	NODATA_OUTPUT	[number] Default: None	Assigns the specified nodata value to output bands.
Additional creation options Optional	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 GDAL driver options section). For Batch Process: separate multiple options with a pipe character (|).
Additional command-line parameters	EXTRA	[string] Default: None	Add extra GDAL command line options

輸出

Label	名稱	Type	說明
Merged	OUTPUT	[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.

24.2.4.5. 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.

參數

Basic parameters

Label	名稱	Type	說明
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. One of: Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
Resampling algorithm	RESAMPLING	[enumeration] Default: 2	The resampling algorithm to be used Options: 0 --- Nearest Neighbour (nearest) 1 --- Bilinear (bilinear) 2 --- Cubic (cubic) 3 --- Cubic Spline (cubicspline) 4 --- Lanczos Windowed Sinc (lanczos) 5 --- Average (average)
Additional creation options Optional	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 GDAL driver options section). For Batch Process: separate multiple options with a pipe character (|).
Additional command-line parameters Optional	EXTRA	[string] Default: None	Add extra GDAL command line options

輸出

Label	名稱	Type	說明
Output	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.

24.2.4.6. 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.

参见

Raster calculator

參數

Basic parameters

Label	名稱	Type	說明
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: None	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: None	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: None	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: None	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: None	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	[number] Default: None	Value to use for nodata
Output raster type	RTYPE	[enumeration] Default: 5	Defines the format of the output raster file. Options: 0 --- Byte 1 --- Int16 2 --- UInt16 3 --- UInt32 4 --- Int32 5 --- Float32 6 --- Float64
Calculated	OUTPUT	[raster] Default: [Save to temporary file]	Specify the output (calculated) raster layer. One of: Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
Additional creation options Optional	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 GDAL driver options section). For Batch Process: separate multiple options with a pipe character (|).
Additional command-line parameters Optional	EXTRA	[string] Default: ''	Add extra GDAL command line options

輸出

Label	名稱	Type	說明
Calculated	OUTPUT	[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.

24.2.4.7. 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: Raster ► Miscellaneous

參數

Basic parameters

Label	名稱	Type	說明
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. One of: Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
Additional command-line parameters Optional	EXTRA	[string] Default: None	Add extra GDAL command line options

輸出

Label	名稱	Type	說明
Layer information	OUTPUT	[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.

24.2.4.8. 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.

參數

Basic parameters

Label	名稱	Type	說明
Input files	INPUT	[raster] [list]	The input raster files
Tile width	TILE_SIZE_X	[number] Default: 256	Width of the tiles in pixels (minimum 0)
Tile height	TILE_SIZE_Y	[number] Default: 256	Height of the tiles in pixels (minimum 0)
Overlap in pixels between consecutive tiles	OVERLAP	[number] Default: 0
Number of pyramid levels to build	LEVELS	[number] Default: 1	Minimum: 0
Output directory	OUTPUT	[folder] Default: [Save to temporary folder]	Specify the output folder for the tiles. One of: Save to a Temporary Directory Save to Directory
CSV file containing the tile(s) georeferencing information	OUTPUT_CSV	[file] Default: [Skip output]	Specify the output file for the tiles. One of: Skip Output Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
Source coordinate reference system Optional	SOURCE_CRS	[crs] Default: None
Resampling method	RESAMPLING	[enumeration] Default: 0	The resampling algorithm to be used Options: 0 --- Nearest Neighbour (nearest) 1 --- Bilinear (bilinear) 2 --- Cubic (cubic) 3 --- Cubic Spline (cubicspline) 4 --- Lanczos Windowed Sinc (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	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 GDAL driver options section). For Batch Process: 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: 0 --- Byte 1 --- Int16 2 --- UInt16 3 --- UInt32 4 --- Int32 5 --- Float32 6 --- Float64 7 --- CInt16 8 --- CInt32 9 --- CFloat32 10 --- CFloat64
Build only the pyramids	ONLY_PYRAMIDS	[boolean] Default: False
Use separate directory for each tile row	DIR_FOR_ROW	[boolean] Default: False

輸出

Label	名稱	Type	說明
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

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.

24.2.4.9. 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: Raster ► Miscellaneous

參數

Basic parameters

Label	名稱	Type	說明
Input files	LAYERS	[raster] [list]	The input raster files. Can be multiple files.
Field name to hold the file path to the indexed rasters	PATH_FIELD_NAME Optional	[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. One of: Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
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)

輸出

Label	名稱	Type	說明
Tile index	OUTPUT	[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.

24.2.4.10. Viewshed

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

參數

Basic parameters

Label	名稱	Type	說明
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	[point]	The location of the observer
Observer height	OBSERVER_HEIGHT	[number] Default: 1.0	The altitude of the observer, in the DEM units
Target height	TARGET_HEIGHT	[number] Default: 1.0	The altitude of the target element, in the DEM units
Maximum distance from observer to compute visibility	MAX_DISTANCE	[number] 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. One of: Save to a Temporary File Save to File...

Advanced parameters

Label	名稱	Type	說明
Additional creation options Optional	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 GDAL driver options section). For Batch Process: separate multiple options with a pipe character (|).
Additional command-line parameters	EXTRA	[string] Default: None	Add extra GDAL command line options

輸出

Label	名稱	Type	說明
Output	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.