cartopy.io.RasterSource#

class cartopy.io.RasterSource[source]#

Define the cartopy raster fetching interface.

A RasterSource instance is able to supply images and associated extents (as a sequence of LocatedImage instances) through its fetch_raster() method.

As a result, further interfacing classes, such as cartopy.mpl.slippy_image_artist.SlippyImageArtist, can then make use of the interface for functionality such as interactive image retrieval with pan and zoom functionality.

fetch_raster(projection, extent, target_resolution)[source]#

Return a sequence of images with extents given some constraining information.

Parameters:

  • projection (cartopy.crs.Projection) – The desired projection of the image.

  • extent (iterable of length 4) – The extent of the requested image in projected coordinates. The resulting image may not be defined exactly by these extents, and so the extent of the resulting image is also returned. The extents must be defined in the form (min_x, max_x, min_y, max_y).

  • target_resolution (iterable of length 2) – The desired resolution of the image as (width, height) in pixels.

Returns:

images – A sequence of LocatedImage instances.

validate_projection(projection)[source]#

Raise an error if this raster source cannot provide images in the specified projection.

Parameters:

projection (cartopy.crs.Projection) – The desired projection of the image.