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GDAL miscellaneous

Build Virtual Raster

Description

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. The algorithm is derived from the GDAL buildvrt utility .

Parameters

Input layers [multipleinput: rasters]
GDAL-supported raster layers.
Resolution [selection]

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

Layer stack [boolean]

With ‘False’ 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

Outputs

Output layer [raster]
Output raster file.

Console usage

processing.runalg('gdalogr:buildvirtualraster', input, resolution, separate, proj_difference, output)

See also

Merge

Description

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. The algorithm is derived from the GDAL merge utility .

Parameters

Input layers [multipleinput: rasters]
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 [selection]

Defines the output raster type. By default this will be ‘Float23’.

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

Outputs

Output layer [raster]
Output raster layer.

Console usage

processing.runalg('gdalogr:merge', input, pct, separate, rtype, output)

See also

Build overviews (pyramids)

Description

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. The algorithm is derived from the GDAL addo utility .

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 [selection]

Calculates the overviews with a defined resampling method.

Options:

  • 0 — nearest
  • 1 — average
  • 2 — gauss
  • 3 — cubic
  • 4 — average_mp
  • 5 — average_magphase
  • 6 — mode

Default: 0

Overview format [selection]

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.

Console usage

processing.runalg('gdalogr:overviews', input, levels, clean, resampling_method, format)

See also

Information

Description

The gdalinfo program lists various information about a GDAL supported raster dataset.

Parameters

Input layer [raster]
Raster layer in input
Suppress GCP info [boolean]

Suppress 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]

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

Default: False

Outputs

Layer information [html]
Raster information in output

Console usage

processing.runalg('gdalorg:rasterinfo', input, nogcp, nometadata, output)

See also

GDAL info

Tile Index

Description

This tool builds a shapefile 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.

Parameters

Input layers [multipleinput: rasters]
The input raster files. Can be multiple files.
Tile index field [string]

Optional.

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

Default: location

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

Outputs

Output layer [vector]
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.

Console usage

processing.runalg('gdalogr:tileindex', input, field_name, proj_difference, output)

See also