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Raster conversion

.. only:: html

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Create Cloud Optimized GeoTIFF

Added in 4.0

Creates a Cloud Optimized GeoTIFF (COG) from the input raster layers.

Parameters

Basic parameters

Label Name Type Description
Input layers INPUT [raster][list] Input raster layers to convert to COG.
Output directory OUTPUT

[file]

Default: [Save to temporary folder]

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

Advanced parameters

Label Name Type Description

Additional creation options

Optional

 CREATION_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 (|).

Outputs

Label Name Type Description
Output directory OUTPUT [file] Directory containing the created Cloud Optimized GeoTIFF(s).
Output layers OUTPUT_LAYERS [raster][list] List of created Cloud Optimized GeoTIFF layer(s).

Python code

Algorithm ID: gdal:createcog

gdal2xyz

Converts raster data to XYZ ASCII file format.

Parameters

Label Name Type Description
Input layer INPUT [raster] Raster layer to convert
Band number BAND

[raster band]

Default: The first band of the input layer

 If the raster is multiband, choose the band you want to convert

Input pixel value to treat as NoData

Optional

 NODATA_INPUT

[numeric: integer]

Default: Not set

Input pixel value to treat as "NoData"

Attention!

Using this parameter requires QGIS installed with GDAL >= 3.7 (see :menuselection:`Help --> About` menu).

Destination NoData

Optional

 NODATA_OUTPUT

[numeric: integer]

Default: Not set

Assign specified "NoData" value to output.

Attention!

Using this parameter requires QGIS installed with GDAL >= 3.7 (see :menuselection:`Help --> About` menu).
Do not output NoData values SKIP_NODATA

[boolean]

Default: False

Do not output "NoData" values.

Attention!

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

[boolean]

Default: False

 Sets whether the output file should be of type comma-separated values (csv).
XYZ ASCII file OUTPUT

[file]

Default: [Save to temporary file]

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

Outputs

Label Name Type Description
XYZ ASCII file INPUT [table] Table file containing the values exported from the raster band.

Python code

Algorithm ID: gdal:gdal2xyz

PCT to RGB

Converts an 8 bit paletted image to a 24 bit RGB. It will convert a pseudocolor band from the input file to an RGB file of the desired format.

This algorithm is derived from the GDAL pct2rgb utility.

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

Parameters

Label Name Type Description
Input layer INPUT [raster] Input 8 bit raster image
Band number BAND

[raster band]

Default: The first band of the input layer

 If the raster is multiband, choose the band you want to convert
Generate a RGBA file RGBA

[boolean]

Default: False

 Sets whether the output file should be of type RGBA.
PCT to RGB OUTPUT

[file]

Default: [Save to temporary file]

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

Outputs

Label Name Type Description
PCT to RGB OUTPUT [raster] 24 bit RGB raster image

Python code

Algorithm ID: gdal:pcttorgb

Polygonize (raster to vector)

Creates vector polygons for all connected regions of pixels in the raster sharing a common pixel value. Each polygon is created with an attribute indicating the pixel value of that polygon.

This algorithm is derived from the GDAL polygonize utility.

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

Parameters

Basic 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 use
Name of the field to create FIELD

[string]

Default: 'DN'

 Specify the field name for the attributes of the connected regions.
Use 8-connectedness EIGHT_CONNECTEDNESS

[boolean]

Default: False

 If not set, raster cells must have a common border to be considered connected (4-connected). If set, touching raster cells are also considered connected (8-connected).
Vectorized OUTPUT

[vector: polygon]

Default: [Save to temporary file]

 Specification of the output (polygon) vector layer. :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
Vectorized OUTPUT [vector: polygon] Output vector layer

Python code

Algorithm ID: gdal:polygonize

Rearrange bands

Creates a new raster using selected band(s) from a given raster layer. The algorithm also makes it possible to reorder the bands for the newly-created raster.

This algorithm is derived from the GDAL translate utility.

Parameters

Basic parameters

Label Name Type Description
Input layer INPUT [raster] Input raster layer
Selected band(s) BANDS

[raster band] [list]

Default: Not set

 Ordered list of the bands to use to create the new raster
Converted OUTPUT

[raster]

Default: [Save to temporary file]

 Specification of the output raster. :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 (|).
Output data type DATA_TYPE

[enumeration]

Default: 0

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

Outputs

Label Name Type Description
Converted OUTPUT [raster] Output raster layer with rearranged bands.

Python code

Algorithm ID: gdal:rearrange_bands

RGB to PCT

Converts a 24 bit RGB image into a 8 bit paletted. Computes an optimal pseudo-color table for the given RGB-image using a median cut algorithm on a downsampled RGB histogram. Then it converts the image into a pseudo-colored image using the color table. This conversion utilizes Floyd-Steinberg dithering (error diffusion) to maximize output image visual quality.

If you want to classify a raster map and want to reduce the number of classes it can be helpful to downsample your image with this algorithm before.

This algorithm is derived from the GDAL rgb2pct utility.

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

Parameters

Label Name Type Description
Input layer INPUT [raster] Input (RGB) raster layer
Number of colors NCOLORS

[numeric: integer]

Default: 2

 The number of colors the resulting image will contain. A value from 2-256 is possible.
RGB to PCT OUTPUT

[raster]

Default: [Save to temporary file]

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

Outputs

Label Name Type Description
RGB to PCT OUTPUT [raster] Output raster layer.

Python code

Algorithm ID: gdal:rgbtopct

Translate (convert format)

Converts raster data between different formats.

This algorithm is derived from the GDAL translate utility.

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

Parameters

Basic parameters

Label Name Type Description
Input layer INPUT [raster] Input raster layer

Override the projection of the output file

Optional

 TARGET_CRS [crs] Specify a projection for the output file

Assign a specified NoData value to output bands

Optional

 NODATA

[numeric: double]

Default: Not set

 Defines the value to use for NoData in the output raster
Copy all subdatasets of this file to individual output files COPY_SUBDATASETS

[boolean]

Default: False

 Create individual files for subdatasets
Converted OUTPUT

[raster]

Default: [Save to temporary file]

 Specification of the output (translated) 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: Not set

 Add extra GDAL command line options
Output data type DATA_TYPE

[enumeration]

Default: 0

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

Outputs

Label Name Type Description
Converted OUTPUT [raster] Output (translated) raster layer.

Python code

Algorithm ID: gdal:translate