23.1.9. Raster analysis¶

Raster boolean AND
Raster boolean OR
Raster calculator
Raster layer statistics
Raster layer unique values report
Raster layer zonal statistics
Raster surface volume
Reclassify by layer
Reclassify by table
Sample raster values
Zonal histogram
Zonal statistics

23.1.9.1. Raster boolean AND ¶

Calculates the boolean AND for a set of input rasters. If all of the input rasters have a non-zero value for a pixel, that pixel will be set to 1 in the output raster. If any of the input rasters have 0 values for the pixel it will be set to 0 in the output raster.

The reference layer parameter specifies an existing raster layer to use as a reference when creating the output raster. The output raster will have the same extent, CRS, and pixel dimensions as this layer.

By default, a nodata pixel in ANY of the input layers will result in a nodata pixel in the output raster. If the Treat nodata values as false option is checked, then nodata inputs will be treated the same as a 0 input value.

23.1.9.1.1. Parameters¶

Label	Name	Type	Description
Input layers	`INPUT`	[raster] [list]	List of input raster layers
Reference layer	`REF_LAYER`	[raster]	The reference layer to create the output layer from (extent, CRS, pixel dimensions)
Treat nodata values as false	`NODATA_AS_FALSE`	[boolean] Default: False	Treat nodata values in the input files as 0 when performing the operation
Output no data value	`NO_DATA`	[number] Default: -9999.0	Value to use for nodata in the output layer
Output data type	`DATA_TYPE`	[enumeration] Default: 5	Output raster data type. Options: 0 — Byte 1 — Int16 2 — UInt16 3 — UInt32 4 — Int32 5 — Float32 6 — Float64 7 — CInt16 8 — CInt32 9 — CFloat32 10 — CFloat64
Output layer	`OUTPUT`	[raster]	Output raster layer

23.1.9.1.2. Outputs¶

Label	Name	Type	Description
Extent	`EXTENT`	[extent]	The extent of the output raster layer
CRS authority identifier	`CRS_AUTHID`	[crs]	The coordinate reference system of the output raster layer
Width in pixels	`WIDTH_IN_PIXELS`	[integer]	The width in pixels of the output raster layer
Height in pixels	`HEIGHT_IN_PIXELS`	[integer]	The height in pixels of the output raster layer
Total pixel count	`TOTAL_PIXEL_COUNT`	[integer]	The count of pixels in the output raster layer
NODATA pixel count	`NODATA_PIXEL_COUNT`	[integer]	The count of nodata pixels in the output raster layer
True pixel count	`TRUE_PIXEL_COUNT`	[integer]	The count of True pixels (value = 1) in the output raster layer
False pixel count	`FALSE_PIXEL_COUNT`	[integer]	The count of False pixels (value = 0) in the output raster layer
Output layer	`OUTPUT`	[raster]	Output raster layer containing the result

23.1.9.1.3. Python code¶

Algorithm ID: qgis:rasterbooleanand

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.

23.1.9.2. Raster boolean OR ¶

Calculates the boolean OR for a set of input rasters. If all of the input rasters have a zero value for a pixel, that pixel will be set to 0 in the output raster. If any of the input rasters have 1 values for the pixel it will be set to 1 in the output raster.

The reference layer parameter specifies an existing raster layer to use as a reference when creating the output raster. The output raster will have the same extent, CRS, and pixel dimensions as this layer.

By default, a nodata pixel in ANY of the input layers will result in a nodata pixel in the output raster. If the Treat nodata values as false option is checked, then nodata inputs will be treated the same as a 0 input value.

23.1.9.2.1. Parameters¶

Label	Name	Type	Description
Input layers	`INPUT`	[raster] [list]	List of input raster layers
Reference layer	`REF_LAYER`	[raster]	The reference layer to create the output layer from (extent, CRS, pixel dimensions)
Treat nodata values as false	`NODATA_AS_FALSE`	[boolean] Default: False	Treat nodata values in the input files as 0 when performing the operation
Output no data value	`NO_DATA`	[number] Default: -9999.0	Value to use for nodata in the output layer
Output data type	`DATA_TYPE`	[enumeration] Default: 5	Output raster data type. Options: 0 — Byte 1 — Int16 2 — UInt16 3 — UInt32 4 — Int32 5 — Float32 6 — Float64 7 — CInt16 8 — CInt32 9 — CFloat32 10 — CFloat64
Output layer	`OUTPUT`	[raster]	Output raster layer

23.1.9.2.2. Outputs¶

Label	Name	Type	Description
Extent	`EXTENT`	[extent]	The extent of the output raster layer
CRS authority identifier	`CRS_AUTHID`	[crs]	The coordinate reference system of the output raster layer
Width in pixels	`WIDTH_IN_PIXELS`	[integer]	The width in pixels of the output raster layer
Height in pixels	`HEIGHT_IN_PIXELS`	[integer]	The height in pixels of the output raster layer
Total pixel count	`TOTAL_PIXEL_COUNT`	[integer]	The count of pixels in the output raster layer
NODATA pixel count	`NODATA_PIXEL_COUNT`	[integer]	The count of nodata pixels in the output raster layer
True pixel count	`TRUE_PIXEL_COUNT`	[integer]	The count of True pixels (value = 1) in the output raster layer
False pixel count	`FALSE_PIXEL_COUNT`	[integer]	The count of False pixels (value = 0) in the output raster layer
Output layer	`OUTPUT`	[raster]	Output raster layer containing the result

23.1.9.2.3. Python code¶

Algorithm ID: qgis:rasterbooleanor

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.

23.1.9.3. Raster calculator ¶

Performs algebraic operations using raster layers.

The resulting layer will have its values computed according to an expression. The expression can contain numerical values, operators and references to any of the layers in the current project.

Note

When using the calculator in The batch processing interface or from the QGIS Python console the files to use have to be specified. The corresponding layers are referred using the base name of the file (without the full path). For instance, if using a layer at path/to/my/rasterfile.tif, the first band of that layer will be referred as rasterfile.tif@1.

23.1.9.3.1. Parameters¶

Label	Name	Type	Description
Layers	GUI only		Shows the list of all raster layers loaded in the legend. These can be used to fill the expression box (double click to add). Raster layers are referred by their name and the number of the band: `layer_name@band_number`. For instance, the first band from a layer named `DEM` will be referred as `DEM@1`.
Operators	GUI only		Contains some calculator like buttons that can be used to fill the expression box.
Expression	`EXPRESSION`	[string]	Expression that will be used to calculate the output raster layer. You can use the operator buttons provided to type directly the expression in this box.
Predefined expressions	GUI only		You can use the predefined `NDVI` expression or you can define new expressions for calculations. The Add… button loads a defined expression (and lets you set the parameters). The Save… button lets you define a new expression.
Reference layer(s) (used for automated extent, cellsize, and CRS) Optional	`LAYERS`	[raster] [list]	Layer(s) that will be used to fetch extent, cell size and CRS. By choosing the layer in this box you avoid filling in all the other parameters by hand. Raster layers are referred by their name and the number of the band: `layer_name@band_number`. For instance, the first band from a layer named `DEM` will be referred as `DEM@1`.
Cell size (use 0 or empty to set it automatically) Optional	`CELLSIZE`	[number]	Cell size of the output raster layer. If the cell size is not specified, the minimum cell size of the selected reference layer(s) will be used. The cell size will be the same for the X and Y axes.
Output extent (xmin, xmax, ymin, ymax)	`EXTENT`	[extent]	Extent of the output raster layer. If the extent is not specified, the minimum extent that covers all the selected reference layers will be used.
Output CRS Optional	`CRS`	[crs]	CRS of the output raster layer. If the output CRS is not specified, the CRS of the first reference layer will be used.
Output	`OUTPUT`	[raster] Default: `[Save to temporary file]`	Specification of the output raster. One of: Save to a Temporary File Save to File… The file encoding can also be changed here.

23.1.9.3.2. Outputs¶

Label	Name	Type	Description
Output	`OUTPUT`	[raster]	Output raster file with the calculated values.

23.1.9.3.3. Python code¶

Algorithm ID: qgis: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.

23.1.9.4. Raster layer statistics ¶

Calculates basic statistics from the values in a given band of the raster layer. The output is loaded in the Processing ▶ Results viewer menu.

23.1.9.4.1. Parameters¶

Label

Name

Type

Description

Input layer

INPUT

[raster]

Input raster layer

Band number

BAND

[raster band]

Default: The first band of the input layer

If the raster is multiband, choose the band you want to get statistics for.

Output

OUTPUT_HTML_FILE

[html]

Default: [Save to temporary file]

Specification of the output file:

Skip Output
Save to a Temporary File
Save to File…

The file encoding can also be changed here.

23.1.9.4.2. Outputs¶

Label	Name	Type	Description
Maximum value	`MAX`	[number]
Mean value	`MEAN`	[number]
Minimum value	`MIN`	[number]
Output	`OUTPUT_HTML_FILE`	[html]	The output file contains the following information: Analyzed file: path of the raster layer Minimum value: minimum value of the raster Maximum value: maximum value of the raster Range: difference between the maximum and minimum values Sum: total sum of the values Mean value: mean of the values Standard deviation: standard deviation of the values Sum of the squares: sum of the squared differences of each observation from the overall mean
Range	`RANGE`	[number]
Standard deviation	`STD_DEV`	[number]
Sum	`SUM`	[number]
Sum of the squares	`SUM_OF_SQUARES`	[number]

23.1.9.4.3. Python code¶

Algorithm ID: qgis:rasterlayerstatistics

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.

23.1.9.5. Raster layer unique values report ¶

Returns the count and area of each unique value in a given raster layer.

23.1.9.5.1. Parameters¶

Label	Name	Type	Description
Input layer	`INPUT`	[raster]	Input raster layer
Band number	`BAND`	[raster band] Default: The first band of the input layer	If the raster is multiband, choose the band you want to get statistics for.
Unique values report	`OUTPUT_HTML_FILE`	[file] Default: `[Save to temporary file]`	Specification of the output file: Skip Output Save to a Temporary File Save to File… The file encoding can also be changed here.
Unique values table	`OUTPUT_TABLE`	[table] Default: `[Skip output]`	Specification of the table for unique values: Skip Output Create Temporary Layer Save to File… Save to GeoPackage… Save to PostGIS Table…… The file encoding can also be changed here.

23.1.9.5.2. Outputs¶

Label	Name	Type	Description
CRS authority identifier	`CRS_AUTHID`	[crs]
Extent	`EXTENT`	[extent]
Height in pixels	`HEIGHT_IN_PIXELS`	[number]
NODATA pixel count	`NODATA_PIXEL_COUNT`	[number]
Total pixel count	`TOTAL_PIXEL_COUNT`	[number]
Unique values report	`OUTPUT_HTML_FILE`	[html]	The output HTML file contains the following information: Analyzed file: the path of the raster layer Extent: xmin, ymin, xmax, ymax coordinates of the extent Projection: projection of the layer Width in pixels: number of columns and pixel width size Height in pixels: number of rows and pixel width size Total pixel count: count of all the pixels NODATA pixel count: count of pixels with NODATA value
Unique values table	`OUTPUT_TABLE`	[table]	A table with three columns: value: pixel value count: count of pixels with this value m²: total area in square meters of pixels with this value.
Width in pixels	`WIDTH_IN_PIXELS`	[number]

23.1.9.5.3. Python code¶

Algorithm ID: qgis:rasterlayeruniquevaluesreport

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.

23.1.9.6. Raster layer zonal statistics ¶

Calculates statistics for a raster layer’s values, categorized by zones defined in another raster layer.

23.1.9.6.1. Parameters¶

Label	Name	Type	Description
Input Layer	`INPUT`	[raster]	Input raster layer
Band number	`BAND`	[raster band] Default: The first band of the raster layer	If the raster is multiband choose the band for which you want to calculate the statistics.
Zones layer	`ZONES`	[raster]	Raster layer defining zones. Zones are given by contiguous pixels having the same pixel value.
Zones band number	`ZONES_BAND`	[raster band] Default: The first band of the raster layer	If the raster is multiband, choose the band that defines the zones
Reference layer Optional	`REF_LAYER`	[enumeration] Default: 0	Raster layer used to calculate the centroids that will be used as reference when determining the zones in the output layer. One of: 0 — Input layer 1 — Zones layer
Statistics	`OUTPUT_TABLE`	[table]	Table with the calculated statistics

23.1.9.6.2. Outputs¶

Label	Name	Type	Description
CRS authority identifier	`CRS_AUTHID`	[crs]
Extent	`EXTENT`	[extent]
Height in pixels	`HEIGHT_IN_PIXELS`	[number]
NODATA pixel count	`NODATA_PIXEL_COUNT`	[number]
Statistics	`OUTPUT_TABLE`	[table]	The output layer contains the following information for each zone: Area: the area in square raster units in the zone; Sum: the total sum of the pixel values in the zone; Count: the number of pixels in the zone; Min: the minimum pixel value in the zone; Max: the maximum pixel value in the zone; Mean: the mean of the pixel values in the zone;
Total pixel count	`TOTAL_PIXEL_COUNT`	[number]
Width in pixels	`WIDTH_IN_PIXELS`	[number]

23.1.9.6.3. Python code¶

Algorithm ID: qgis:rasterlayerzonalstats

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.

23.1.9.7. Raster surface volume ¶

Calculates the volume under a raster surface relative to a given base level. This is mainly useful for Digital Elevation Models (DEM).

23.1.9.7.1. Parameters¶

Label	Name	Type	Description
INPUT layer	`INPUT`	[raster]	Input raster, representing a surface
Band number	`BAND`	[raster band] Default: The first band of the raster layer	If the raster is multiband, choose the band that shall define the surface.
Base level	`LEVEL`	[number] Default: 0.0	Define a base or reference value. This base is used in the volume calculation according to the `Method` parameter (see below).
Method	`METHOD`	[enumeration] Default: 0	Define the method for the volume calculation given by the difference between the raster pixel value and the `Base level`. Options: 0 — Count Only Above Base Level: only pixels above the base level will add to the volume. 1 — Count Only Below Base Level: only pixels below the base level will add to the volume. 2 — Subtract Volumes Below Base level: pixels above the base level will add to the volume, pixels below the base level will subtract from the volume. 3 — Add Volumes Below Base level: Add the volume regardless whether the pixel is above or below the base level. This is equivalent to sum the absolute values of the difference between the pixel value and the base level.
Surface volume report	`OUTPUT_HTML_FILE`	[html] Default: `[Save to temporary file]`	Specification of the output HTML report. One of: Skip output Save to Temporary File Save to File… The file encoding can also be changed here.
Surface volume table	`OUTPUT_TABLE`	[table] Default: `[Skip output]`	Specification of the output table. One of: Skip output Create Temporary Layer (`TEMPORARY_OUTPUT`) Save to File… Save to Geopackage… Save to PostGIS Table… The file encoding can also be changed here.

23.1.9.7.2. Outputs¶

Label	Name	Type	Description
Volume	`VOLUME`	[number]	The calculated volume
Area	`AREA`	[number]	The area in square map units
Pixel_count	`PIXEL_COUNT`	[number]	The total number of pixels that have been analyzed
Surface volume report	`OUTPUT_HTML_FILE`	[html]	The output report (containing volume, area and pixel count) in HTML format
Surface volume table	`OUTPUT_TABLE`	[table]	The output table (containing volume, area and pixel count)

23.1.9.7.3. Python code¶

Algorithm ID: qgis:rastersurfacevolume

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.

23.1.9.8. Reclassify by layer ¶

Reclassifies a raster band by assigning new class values based on the ranges specified in a vector table.

23.1.9.8.1. Parameters¶

Label	Name	Type	Description
Raster layer	`INPUT_RASTER`	[raster]	Raster layer to reclassify
Band number	`RASTER_BAND`	[raster band] Default: The first band of the raster layer	If the raster is multiband, choose the band you want to reclassify.
Layer containing class breaks	`INPUT_TABLE`	[vector: any]	Vector layer containing the values to use for classification.
Minimum class value field	`MIN_FIELD`	[tablefield: numeric]	Field with the minimum value of the range for the class.
Maximum class value field	`MAX_FIELD`	[tablefield: numeric]	Field with the maximum value of the range for the class.
Output value field	`VALUE_FIELD`	[tablefield: numeric]	Field with the value that will be assigned to the pixels that fall in the class (between the corresponding min and max values).
Output no data value	`NO_DATA`	[number] Default: -9999.0	Value to apply to no data values.
Range boundaries	`RANGE_BOUNDARIES`	[enumeration] Default: 0	Defines comparison rules for the classification. Options: 0 — min < value <= max 1 — min <= value < max 2 — min <= value <= max 3 — min < value < max
Use no data when no range matches value	`NODATA_FOR_MISSING`	[boolean] Default: False	Values that do not belong to a class will result in the no data value. If False, the original value is kept.
Output data type	`DATA_TYPE`	[enumeration] Default: 5	Defines the data type 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
Reclassified raster	`OUTPUT`	[raster]	Specification of the output raster. One of: Save to a Temporary File Save to File… The file encoding can also be changed here.

23.1.9.8.2. Outputs¶

Label	Name	Type	Description
Reclassified raster	`OUTPUT`	[raster]	Output raster layer with reclassified band values

23.1.9.8.3. Python code¶

Algorithm ID: qgis:reclassifybylayer

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.

23.1.9.9. Reclassify by table ¶

Reclassifies a raster band by assigning new class values based on the ranges specified in a fixed table.

23.1.9.9.1. Parameters¶

Label	Name	Type	Description
Raster layer	`INPUT_RASTER`	[raster]	Raster layer to reclassify
Band number	`RASTER_BAND`	[raster band] Default: 1	Raster band for which you want to recalculate values.
Reclassification table	`TABLE`	[table]	A 3-columns table to fill with the values to set the boundaries of each class (`Minimum` and `Maximum`) and the new `Value` to assign to the band values that fall in the class.
Output no data value	`NO_DATA`	[number] Default: -9999.0	Value to apply to no data values.
Range boundaries	`RANGE_BOUNDARIES`	[enumeration] Default: 0	Defines comparison rules for the classification. Options: 0 — min < value <= max 1 — min <= value < max 2 — min <= value <= max 3 — min < value < max
Use no data when no range matches value	`NODATA_FOR_MISSING`	[boolean] Default: False	Applies the no data value to band values that do not fall in any class. If False, the original value is kept.
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
Reclassified raster	`OUTPUT`	[raster] Default: ‘[Save to temporary file]’	Specification of the output raster layer. One of: Save to a Temporary File Save to File… The file encoding can also be changed here

23.1.9.9.2. Outputs¶

Label

Name

Type

Description

Reclassified raster

OUTPUT

[raster]

Default: ‘[Save to temporary file]’

The output raster layer.

23.1.9.9.3. Python code¶

Algorithm ID: qgis:reclassifybytable

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.

23.1.9.10. Sample raster values ¶

Extracts raster values at the point locations. If the raster layer is multiband, each band is sampled.

The attribute table of the resulting layer will have as many new columns as the raster layer band count.

23.1.9.10.1. Parameters¶

Label	Name	Type	Description
Input Point Layer	`INPUT`	[vector: point]	Point vector layer to use for sampling
Raster Layer to sample	`RASTERCOPY`	[raster]	Raster layer to sample at the given point locations.
Output column prefix	`COLUMN_PREFIX`	[string] Default: ‘rvalue’	Prefix for the names of the added columns.
Sampled Points (Optional)	`OUTPUT`	[vector: point] Default: `[Create temporary layer]`	Specify the output layer containing the sampled values. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Save to File… Save to GeoPackage… Save to PostGIS Table… The file encoding can also be changed here.

23.1.9.10.2. Outputs¶

Label

Name

Type

Description

Sampled Points

(Optional)

OUTPUT

[vector: point]

The output layer containing the sampled values.

23.1.9.10.3. Python code¶

Algorithm ID: qgis:rastersampling

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.

23.1.9.11. Zonal histogram ¶

Appends fields representing counts of each unique value from a raster layer contained within polygon features.

The output layer attribute table will have as many fields as the unique values of the raster layer that intersects the polygon(s).

../../../../_images/raster_histogram.png

Fig. 23.7 Raster layer histogram example¶

23.1.9.11.1. Parameters¶

Label	Name	Type	Description
Raster layer	`INPUT_RASTER`	[raster]	Input raster layer.
Band number	`RASTER_BAND`	[raster band] Default: The first band of the input layer	If the raster is multiband, choose a band.
Vector layer containing zones	`INPUT_VECTOR`	[vector: polygon]	Vector polygon layer that defines the zones.
Output column prefix	`COLUMN_PREFIX` Optional	[string] Default: ‘HISTO_’	Prefix for the output columns names.
Output zones	`OUTPUT`	[vector: polygon] Default: `[Create temporary layer]`	Specify the output vector polygon layer. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Save to File… Save to GeoPackage… Save to PostGIS Table… The file encoding can also be changed here.

23.1.9.11.2. Outputs¶

Label

Name

Type

Description

Output zones

(Optional)

OUTPUT

[vector: polygon]

Default: [Create temporary layer]

The output vector polygon layer.

23.1.9.11.3. Python code¶

Algorithm ID: qgis:zonalhistogram

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.

23.1.9.12. Zonal statistics ¶

Calculates statistics of a raster layer for each feature of an overlapping polygon vector layer.

Warning

No new output file will be created. The algorithm adds new columns to the source vector layer.

23.1.9.12.1. Parameters¶

Label	Name	Type	Description
Raster layer	`INPUT_RASTER`	[raster]	Input raster layer.
Raster band	`RASTER_BAND`	[raster band] Default: The first band of the input layer	If the raster is multiband, choose a band for the statistics.
Vector layer containing zones	`INPUT_VECTOR`	[vector: polygon]	Vector polygon layer that defines the zones.
Output column prefix	`COLUMN_PREFIX`	[string] Default: ‘_’	Prefix for the output columns names.
Statistics to calculate	`STATISTICS`	[enumeration] [list] Default: [0,1,2]	List of statistical operator for the output. Options: 0 — Count 1 — Sum 2 — Mean 3 — Median 4 — St. dev. 5 — Minimum 6 — Maximum 7 — Range 8 — Minority 9 — Majority 10 — Variety 11 — Variance

23.1.9.12.2. Outputs¶

Label	Name	Type	Description
Vector layer containing zones	`INPUT_VECTOR`	[vector: polygon]	The input zone vector layer with added statistics.

23.1.9.12.3. Python code¶

Algorithm ID: qgis:zonalstatistics

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.