Spatial subset

From AWF-Wiki
Revision as of 11:53, 9 November 2020 by Hfuchs (Talk | contribs)

Jump to: navigation, search

Interactive box selection

  1. Click the Open Data Source Manager QGIS 3.0 datasource.png and Add raster layer QGIS 2.0 addrast.png and select a multiband raster file.
  2. Raster --> Extraction ---> Clip Raster by Extent
  3. Input layer: Choose a loaded raster file from the drop down list or click QGIS file select.png to browse for a file.
  4. Define the clipping extent by clicking QGIS file select.png and select Draw on canvas. The clipping mode is now active. Hold a left click on the map canvas dragging a box of your region of interest.
  5. Clipped (extent): click QGIS file select.png to choose a new file name for the subset image.
  6. Adjust the extent coordinates in the text file rounding the coordinates (upper left and lower right).

Qgis raster clipper.png

  • Click Run.

Masking by vector polygon

  • Load the vector file (e.g. administrative boundary).
  • Select a community of your choice: right click Open Attribute Table
  • Raster --> Extraction ---> Clip Raster by Mask Layer...
  1. Input layer: Choose a loaded raster file from the drop down list or click Select to browse to a file. * Make sure that the CRS is the same like the image file (here WGS84/UTM Zone 32, EPSG:32632) that you wish to be clipped!
  2. Mask layer: Select the vector file (s. above).
  3. Switch checkbox on: Selected features only.
  4. Assign a specofied nodata value: 65535
  5. Clipped (mask)): click Select to choose a new file name for the subset image.
  6. Switch the checkbox on: Crop the extent of the target dataset to the extent of the cutline. All image data outside the polygon will be masked.
  7. Click Run.

Qgis raster mask.png

Personal tools
Namespaces

Variants
Actions
Navigation
Development
Toolbox
Print/export