Spatial subset
From AWF-Wiki
(Difference between revisions)
(→Interactive box selection) |
(→Masking by vector polygon) |
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# Adjust the extent coordinates in the text file rounding the coordinates (upper left and lower right). | # Adjust the extent coordinates in the text file rounding the coordinates (upper left and lower right). | ||
[[File:Qgis_raster_clipper.png|700px]] | [[File:Qgis_raster_clipper.png|700px]] | ||
| − | + | * Click {{button|text=Run}}. | |
== Masking by vector polygon == | == Masking by vector polygon == | ||
| Line 14: | Line 14: | ||
* {{mitem|text=Raster --> Extraction ---> Clip Raster by Mask Layer...}} | * {{mitem|text=Raster --> Extraction ---> Clip Raster by Mask Layer...}} | ||
| − | # Input | + | # Input layer: Choose a loaded raster file from the drop down list or click [[File:QGIS_file_select.png]] to browse to a file. |
# Mask layer: Select the vector file (s. above). | # Mask layer: Select the vector file (s. above). | ||
| − | |||
# Assign a specofied nodata value: {{button|text=65535}} | # Assign a specofied nodata value: {{button|text=65535}} | ||
| − | + | # Switch the checkbox on: '''Match the extent of the clipped raster to the extent of the mask layer'''. All image data outside the polygon will be masked. | |
| − | # Switch the checkbox on: ''' | + | # Clipped (extent)): click {{button|text=Select}} to choose a new file name for the subset image. |
# Click {{button|text=Run}}. | # Click {{button|text=Run}}. | ||
| − | [[File:Qgis_raster_mask.png| | + | [[File:Qgis_raster_mask.png|400px]] |
[[Category: Working with Raster Data]] | [[Category: Working with Raster Data]] | ||
Latest revision as of 10:57, 31 May 2021
[edit] Interactive box selection
- Click the Open Data Source Manager
and Add raster layer 
and select a multiband raster file.
- Raster --> Extraction ---> Clip Raster by Extent
- Input layer: Choose a loaded raster file from the drop down list or click
to browse for a file.
- Define the clipping extent by clicking 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.
- Clipped (extent): click to choose a new file name for the subset image.
- Adjust the extent coordinates in the text file rounding the coordinates (upper left and lower right).
- Click Run.
[edit] 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...
- Input layer: Choose a loaded raster file from the drop down list or click to browse to a file.
- Mask layer: Select the vector file (s. above).
- Assign a specofied nodata value: 65535
- Switch the checkbox on: Match the extent of the clipped raster to the extent of the mask layer. All image data outside the polygon will be masked.
- Clipped (extent)): click Select to choose a new file name for the subset image.
- Click Run.
