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Raster miscellaneous

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

Parameters

Input layer [raster]
Input raster layer.
Overview levels [string]

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.

Default: 2 4 8 16

Remove all existing overviews [boolean]

Removes existing overviews from the raster. By default these aren’t removed.

Default: False

Resampling method [enumeration]

Optional

Calculates the overviews with a defined resampling method.

Options:

  • 0 — Nearest neighbour
  • 1 — Average
  • 2 — Gaussian
  • 3 — Cubic convolution
  • 4 — B-Spline convolution
  • 5 — Lanczos windowed sinc
  • 6 — Average MP
  • 7 — Average in mag/phase space
  • 8 — Mode

Default: 0

Overview format [enumeration]

Optional

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

Options:

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

Default: 0

Outputs

Output layer [raster]
Output raster layer with 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: Raster ‣ Miscellaneous

Parameters

Input layers [raster] [list]
GDAL-supported raster layers.
Resolution [enumeration]

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

Options:

  • 0 — average
  • 1 — highest
  • 2 — lowest

Default: 0

Place each input file into a separate band [boolean]

With ‘True’ you can define that each raster file goes into a separated stacked band in the VRT band.

Default: True

Allow projection difference [boolean]

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

Default: False

Add alpha mask band to VRT when source raster has none [boolean]
Adds an alpha mask band to the VRT when the source raster has none.
Override projection for the output file [crs]

Optional

Overrides the projection for the output file. No reprojection is done.

Outputs

Virtual [raster]
Output raster file

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

Parameters

Input layers [raster] [list]
Input raster layers.
Grab pseudocolor table from first layer [boolean]

The pseudocolor table from the first layer will be used for the coloring.

Default: False

Layer stack [boolean]

If ‘True’ is chosen each input file will be placed into a separate stacked band.

Default: False

Output raster type [enumeration]

Defines the output raster type. By default this will be ‘Float32’.

Options:

  • 0 — Byte
  • 1 — Int16
  • 2 — UInt16
  • 3 — UInt32
  • 4 — Int32
  • 5 — Float32
  • 6 — Float64
  • 7 — CInt16
  • 8 — CInt32
  • 9 — CFloat32
  • 10 — CFloat64

Default: 5

Input pixel value to treat as "nodata" [number]

Optional

Ignores pixels from files being merged in with this pixel value.

Assign specified "nodata" value to output [number]

Optional

Assigns the specified nodata value to output bands.

Additional creation options

Optional

Allows to add one or more creation options that can be used to control particulars (colorimetry, block size, file compression…) about the file to be created. For convenience, you can rely on predefined profiles (see GDAL driver options section).

Outputs

Output layer [raster]
Output raster layer.

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

Parameters

Input layer [raster]
Raster layer in input.
Force computation of the actual min/max values for each band [boolean]
Forces computation of the actual min/max values for each band in the dataset.
Read and display image statistics (force computation if necessary) [boolean]
Reads and displays image statistics. Forces computation if no statistics are stored in an image.
Suppress GCP info [boolean]

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.

Default: False

Suppress metadata info [boolean]

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

Default: False

Outputs

Layer information [html]
Raster information in output.

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

Parameters

Input files [raster] [list]
The input raster files. Can be multiple files.
Field name to hold the file path to the indexed rasters [string]

Optional

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

Default: location

Store absolute path to the indexed rasters [boolean]

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.

Default: False

Skip files with different projection reference [boolean]

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.

Default: False

Transform geometries to the given CRS [crs]

Optional

Geometries of input files will be transformed to the desired 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 [string]

Optional

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]

Optional

Possible values are:

  • 0 — Auto
  • 1 — Well-known text (WKT)
  • 2 — EPSG
  • 3 — Proj

Default: 0

Outputs

Tile index [vector: polygon]
The name of the output file to create/append to. The default shapefile will be created if it doesn’t already exist, otherwise it will append to the existing file.