Osm tile loader

OSM tile loader.

This module implements downloading tiles from given OSM tile server.

OSMTileLoader(
    tile_server_url,
    zoom,
    verbose=False,
    resource_type="png",
    auth_token=None,
    data_collector=None,
    storage_path=None,
)

OSM Tile Loader.

Download raster tiles from user specified tile server, like listed in [1]. Loader finds x, y coordinates [2] for specified area and downloads tiles. Address is built with schema {tile_server_url}/{zoom}/{x}/{y}.{resource_type}

References

1. https://wiki.openstreetmap.org/wiki/Raster_tile_providers
2. https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames

PARAMETER	DESCRIPTION
tile_server_url	url of tile server, without z, x, y parameters TYPE: str
zoom	zoom level [1] TYPE: int
verbose	should print logs. Defaults to False. TYPE: bool DEFAULT: False
resource_type	file extension. Added to the end of url. Defaults to "png". TYPE: str DEFAULT: 'png'
auth_token	auth token. Added as access_token parameter to request. Defaults to None. TYPE: str DEFAULT: None
data_collector	DataCollector object or TYPE: Union[str, DataCollector] DEFAULT: None
storage_path	path to save data, used with SavingDataCollector. Defaults to None. TYPE: Union[str, Path] DEFAULT: None

References

1. https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames

Source code in srai/loaders/osm_loaders/osm_tile_loader.py

def __init__(
    self,
    tile_server_url: str,
    zoom: int,
    verbose: bool = False,
    resource_type: str = "png",
    auth_token: Optional[str] = None,
    data_collector: Optional[Union[str, DataCollector]] = None,
    storage_path: Optional[Union[str, Path]] = None,
) -> None:
    """
    Initialize TileLoader.

    Args:
        tile_server_url (str): url of tile server, without z, x, y parameters
        zoom (int): zoom level [1]
        verbose (bool, optional): should print logs. Defaults to False.
        resource_type (str, optional): file extension. Added to the end of url.
            Defaults to "png".
        auth_token (str, optional): auth token. Added as access_token parameter
            to request. Defaults to None.
        data_collector (Union[str, DataCollector], optional): DataCollector object or
        enum defining default collector. If None uses InMemoryDataCollector. Defaults to None.
        If `return` uses  InMemoryDataCollector
        If `save` uses  SavingDataCollector
        storage_path (Union[str, Path], optional): path to save data,
            used with SavingDataCollector. Defaults to None.

    References:
        1. https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
    """
    import_optional_dependencies(dependency_group="osm", modules=["PIL"])
    self.zoom = zoom
    self.verbose = verbose
    self.resource_type = resource_type
    self.base_url = urljoin(tile_server_url, "{0}/{1}/{2}." + resource_type)
    self.auth_token = auth_token
    self.save_path = storage_path
    self.data_collector = (
        self._get_collector(data_collector)
        if data_collector is not None
        else InMemoryDataCollector()
    )
    self.regionalizer = SlippyMapRegionalizer(zoom=self.zoom)

load(area)

Return all tiles of region.

PARAMETER	DESCRIPTION
area	Area for which to download objects. TYPE: Union[BaseGeometry, Iterable[BaseGeometry], GeoSeries, GeoDataFrame]

RETURNS	DESCRIPTION
GeoDataFrame	gpd.GeoDataFrame: Pandas of tiles for each region in area transformed by DataCollector

Source code in srai/loaders/osm_loaders/osm_tile_loader.py

def load(
    self,
    area: Union[BaseGeometry, Iterable[BaseGeometry], gpd.GeoSeries, gpd.GeoDataFrame],
) -> gpd.GeoDataFrame:
    """
    Return all tiles of region.

    Args:
        area (Union[BaseGeometry, Iterable[BaseGeometry], gpd.GeoSeries, gpd.GeoDataFrame]):
            Area for which to download objects.

    Returns:
        gpd.GeoDataFrame: Pandas of tiles for each region in area transformed by DataCollector
    """
    area_wgs84 = prepare_area_gdf_for_loader(area)
    regions = self.regionalizer.transform(gdf=area_wgs84)
    regions["tile"] = regions.apply(self._get_tile_for_area, axis=1)
    return regions

get_tile_by_x_y(x, y, idx=None)

Download single tile from tile server. Return tile processed by DataCollector.

PARAMETER	DESCRIPTION
x(int)	x tile coordinate
y(int)	y tile coordinate
idx	id of tile, if non created as x_y_self.zoom TYPE: Any DEFAULT: None

Source code in srai/loaders/osm_loaders/osm_tile_loader.py

def get_tile_by_x_y(self, x: int, y: int, idx: Any = None) -> Any:
    """
    Download single tile from tile server. Return tile processed by DataCollector.

    Args:
        x(int): x tile coordinate
        y(int): y tile coordinate
        idx (Any): id of tile, if non created as x_y_self.zoom
    """
    from PIL import Image

    if idx is None:
        idx = f"{x}_{y}_{self.zoom}"
    url = self.base_url.format(self.zoom, x, y)
    if self.verbose:
        print(f"Getting tile from url: {url}")
    content = requests.get(url, params=dict(access_token=self.auth_token)).content
    tile = Image.open(BytesIO(content))
    return self.data_collector.store(idx, tile)