gemgis.raster.clip_by_polygon#

gemgis.raster.clip_by_polygon(raster: Union[rasterio.io.DatasetReader, numpy.ndarray], polygon: shapely.geometry.polygon.Polygon, raster_extent: List[Union[int, float]] = None, save_clipped_raster: bool = False, path: str = 'raster_clipped.tif', overwrite_file: bool = False, create_directory: bool = False) → numpy.ndarray#

Clipping/masking a rasterio raster or np.ndarray by a given shapely Polygon

Parameters

  • raster (Union[rasterio.io.DatasetReader, np.ndarray]) – Array or Rasterio object to be clipped

  • polygon (shapely.geometry.polygon.Polygon) – Shapely polygon defining the extent of the data, e.g. polygon = Polygon([(0, 0), (1, 1), (1, 0)])

  • raster_extent (List[Union[int, float]]) – List of float values defining the extent of the raster, default None, e.g. raster_extent=[0, 972, 0, 1069]

  • save_clipped_raster (bool) – Variable to save the raster after clipping, default False. Options include: True or False, default set to False

  • path (str) – Path where the raster is saved, e.g. path='raster_clipped.tif

  • overwrite_file (bool) – Variable to overwrite an already existing file. Options include: True or False, default set to False

  • create_directory (bool) – Variable to create a new directory of directory does not exist Options include: True or False, default set to False

Returns

raster_clipped – Clipped array after clipping

Return type

np.ndarray

New in version 1.0.x.

Example

>>> # Loading Libraries and File
>>> import gemgis as gg
>>> import rasterio
>>> from shapely.geometry import Polygon
>>> raster = rasterio.open(fp='raster.tif')
>>> raster.read(1).shape
(275, 250)

>>> # Creating Shapely Polygon and defining raster extent
>>> polygon = Polygon([(250, 250), (500, 250), (500, 500), (250, 500)])
>>> raster_extent = [0, 972, 0, 1069]

>>> # Clipping the raster by a Shapely Polygon
>>> raster_clipped = gg.raster.clip_by_polygon(raster=raster, polygon=polygon, raster_extent=raster_extent)
>>> raster_clipped.shape
(65, 65)

See also

clip_by_bbox

Clipping raster by a Bounding Box