Source code for torchgeo.datasets.cbf
# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License.
"""Canadian Building Footprints dataset."""
import os
from collections.abc import Callable, Iterable
from typing import Any
import matplotlib.pyplot as plt
from matplotlib.figure import Figure
from rasterio.crs import CRS
from .geo import VectorDataset
from .utils import DatasetNotFoundError, check_integrity, download_and_extract_archive
[docs]class CanadianBuildingFootprints(VectorDataset):
"""Canadian Building Footprints dataset.
The `Canadian Building Footprints
<https://github.com/Microsoft/CanadianBuildingFootprints>`__ dataset contains
11,842,186 computer generated building footprints in all Canadian provinces and
territories in GeoJSON format. This data is freely available for download and use.
"""
# TODO: how does one cite this dataset?
# https://github.com/microsoft/CanadianBuildingFootprints/issues/11
url = "https://usbuildingdata.blob.core.windows.net/canadian-buildings-v2/"
provinces_territories = [
"Alberta",
"BritishColumbia",
"Manitoba",
"NewBrunswick",
"NewfoundlandAndLabrador",
"NorthwestTerritories",
"NovaScotia",
"Nunavut",
"Ontario",
"PrinceEdwardIsland",
"Quebec",
"Saskatchewan",
"YukonTerritory",
]
md5s = [
"8b4190424e57bb0902bd8ecb95a9235b",
"fea05d6eb0006710729c675de63db839",
"adf11187362624d68f9c69aaa693c46f",
"44269d4ec89521735389ef9752ee8642",
"65dd92b1f3f5f7222ae5edfad616d266",
"346d70a682b95b451b81b47f660fd0e2",
"bd57cb1a7822d72610215fca20a12602",
"c1f29b73cdff9a6a9dd7d086b31ef2cf",
"76ba4b7059c5717989ce34977cad42b2",
"2e4a3fa47b3558503e61572c59ac5963",
"9ff4417ae00354d39a0cf193c8df592c",
"a51078d8e60082c7d3a3818240da6dd5",
"c11f3bd914ecabd7cac2cb2871ec0261",
]
[docs] def __init__(
self,
paths: str | Iterable[str] = "data",
crs: CRS | None = None,
res: float = 0.00001,
transforms: Callable[[dict[str, Any]], dict[str, Any]] | None = None,
download: bool = False,
checksum: bool = False,
) -> None:
"""Initialize a new Dataset instance.
Args:
paths: one or more root directories to search or files to load
crs: :term:`coordinate reference system (CRS)` to warp to
(defaults to the CRS of the first file found)
res: resolution of the dataset in units of CRS
transforms: a function/transform that takes an input sample
and returns a transformed version
download: if True, download dataset and store it in the root directory
checksum: if True, check the MD5 of the downloaded files (may be slow)
Raises:
DatasetNotFoundError: If dataset is not found and *download* is False.
.. versionchanged:: 0.5
*root* was renamed to *paths*.
"""
self.paths = paths
self.checksum = checksum
if download:
self._download()
if not self._check_integrity():
raise DatasetNotFoundError(self)
super().__init__(paths, crs, res, transforms)
def _check_integrity(self) -> bool:
"""Check integrity of dataset.
Returns:
True if dataset files are found and/or MD5s match, else False
"""
assert isinstance(self.paths, str)
for prov_terr, md5 in zip(self.provinces_territories, self.md5s):
filepath = os.path.join(self.paths, prov_terr + ".zip")
if not check_integrity(filepath, md5 if self.checksum else None):
return False
return True
def _download(self) -> None:
"""Download the dataset and extract it."""
if self._check_integrity():
print("Files already downloaded and verified")
return
assert isinstance(self.paths, str)
for prov_terr, md5 in zip(self.provinces_territories, self.md5s):
download_and_extract_archive(
self.url + prov_terr + ".zip",
self.paths,
md5=md5 if self.checksum else None,
)
[docs] def plot(
self,
sample: dict[str, Any],
show_titles: bool = True,
suptitle: str | None = None,
) -> Figure:
"""Plot a sample from the dataset.
Args:
sample: a sample returned by :meth:`VectorDataset.__getitem__`
show_titles: flag indicating whether to show titles above each panel
suptitle: optional string to use as a suptitle
Returns:
a matplotlib Figure with the rendered sample
.. versionchanged:: 0.3
Method now takes a sample dict, not a Tensor. Additionally, it is possible
to show subplot titles and/or use a custom suptitle.
"""
image = sample["mask"].squeeze(0)
ncols = 1
showing_prediction = "prediction" in sample
if showing_prediction:
pred = sample["prediction"].squeeze(0)
ncols = 2
fig, axs = plt.subplots(nrows=1, ncols=ncols, figsize=(4, 4))
if showing_prediction:
axs[0].imshow(image)
axs[0].axis("off")
axs[1].imshow(pred)
axs[1].axis("off")
if show_titles:
axs[0].set_title("Mask")
axs[1].set_title("Prediction")
else:
axs.imshow(image)
axs.axis("off")
if show_titles:
axs.set_title("Mask")
if suptitle is not None:
plt.suptitle(suptitle)
return fig