def from_id(cls, scene_id, metadata_client=None):
"""
Return the metadata for a Descartes Labs scene ID as a Scene object.
Also returns a :class:`~descarteslabs.scenes.geocontext.GeoContext`
for loading the Scene's original, unwarped data.
Parameters
----------
scene_id: str
Descartes Labs scene ID,
e.g. "landsat:LC08:PRE:TOAR:meta_LC80270312016188_v1"
metadata_client : Metadata, optional
Unneeded in general use; lets you use a specific client instance
with non-default auth and parameters.
Returns
-------
scene: Scene
Scene instance with metadata loaded from the Descartes Labs catalog
ctx: AOI
A :class:`~descarteslabs.scenes.geocontext.GeoContext`for loading this Scene's original data.
The defaults used are described in `Scene.default_ctx`.
Example
-------
>>> import descarteslabs as dl
>>> scene, ctx = dl.scenes.Scene.from_id("landsat:LC08:PRE:TOAR:meta_LC80260322016197_v1") # doctest: +SKIP
>>> ctx # doctest: +SKIP
AOI(geometry=None,
resolution=15.0,
crs='EPSG:32615',
align_pixels=False,
bounds=(348592.5, 4345567.5, 581632.5, 4582807.5),
bounds_crs='EPSG:32615',
shape=None)
>>> scene.properties.date # doctest: +SKIP
datetime.datetime(2016, 7, 15, 16, 53, 59, 495435)
Raises
------
NotFoundError
If the ``scene_id`` cannot be found in the Descartes Labs catalog
"""
if metadata_client is None:
metadata_client = Metadata()
metadata = metadata_client.get(scene_id)
metadata = {
"type": "Feature",
"geometry": metadata.pop("geometry"),
"id": metadata.pop("id"),
"key": metadata.pop("key"),
"properties": metadata
}
bands = metadata_client.get_bands_by_id(scene_id)
scene = cls(metadata, bands)
return scene, scene.default_ctx()
def from_id(cls, scene_id, metadata_client=None):
"""
Return the metadata for a Descartes Labs scene ID as a Scene object.
Also returns a GeoContext with reasonable defaults to use
when loading the Scene's ndarray.
Parameters
----------
scene_id: str
Descartes Labs scene ID,
e.g. "landsat:LC08:PRE:TOAR:meta_LC80270312016188_v1"
metadata_client : Metadata, optional
Unneeded in general use; lets you use a specific client instance
with non-default auth and parameters.
Returns
-------
scene: Scene
Scene instance with metadata loaded from the Descartes Labs catalog
ctx: AOI
A default GeoContext useful for loading this Scene.
These defaults are used:
* bounds: bounds of the Scene's geometry
* resolution: the finest resolution of any band in the scene
* crs: native CRS of the Scene (generally, a UTM CRS)
* align_pixels: True
Example
-------
>>> import descarteslabs as dl
>>> scene, ctx = dl.scenes.Scene.from_id("landsat:LC08:PRE:TOAR:meta_LC80260322016197_v1")
>>> ctx
AOI(geometry=None,
resolution=15,
crs='EPSG:32615',
align_pixels=True,
bounds=(-94.724166, 39.2784859, -92.0686956, 41.3717716),
shape=None)
>>> scene.properties.date
datetime.datetime(2016, 7, 15, 16, 53, 59, 495435)
Raises
------
NotFoundError
If the ``scene_id`` cannot be found in the Descartes Labs catalog
"""
if metadata_client is None:
metadata_client = Metadata()
metadata = metadata_client.get(scene_id)
metadata = {
"type": "Feature",
"geometry": metadata.pop("geometry"),
"id": metadata.pop("id"),
"key": metadata.pop("key"),
"properties": metadata
}
bands = metadata_client.get_bands_by_id(scene_id)
scene = cls(metadata, bands)
# TODO: not sure what default res should be
try:
default_resolution = min(
filter(None,
[b.get("resolution") for b in six.itervalues(bands)]))
except ValueError:
default_resolution = 100
# QUESTION: default bounds will now be in WGS84, not UTM
# indeed, there's no way to give bounds in UTM besides with a DLTile,
# which means you could get off-by-one issues with loading an entire scene
# at native resolution, where the WGS84 bounds result in a slightly differently
# sized raster than native UTM bounds would with reprojection errors
try:
bounds = scene.geometry.bounds
except AttributeError:
xs, ys = zip(*scene.geometry["coordinates"][0])
bounds = (min(xs), min(ys), max(xs), max(ys))
default_ctx = geocontext.AOI(bounds=bounds,
resolution=default_resolution,
crs=scene.properties["crs"])
return scene, default_ctx