Accessing the underlying tile image in holoviews

Question

Is it possible to access the underlying image from hv.element.tiles.EsriImagery()? I would like to access the tile image and run an object detection model on it.

When I try accessing the .data property, I see the template url https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{Z}/{Y}/{X}.jpg, however I am interested in accessing the image of the specific tile that is being displayed and then using it for additional processing.

Answer 1

Yes, it's possible, and we have an example like just that! It's not yet fully published, but the source code is reachable at https://github.com/pyviz-topics/examples/pull/193 . The relevant function is in GeoViews (geoviews/util.py):

def get_tile_rgb(tile_source, bbox, zoom_level, bbox_crs=ccrs.PlateCarree()):
    """
    Returns an RGB element given a tile_source, bounding box and zoom level.

    Parameters
    ----------
    tile_source: WMTS element or string URL
      The tile source to download the tiles from.
    bbox: tuple
      A four tuple specifying the (left, bottom, right, top) corners of the
      domain to download the tiles for.
    zoom_level: int
      The zoom level at which to download the tiles
    bbox_crs: ccrs.CRs
      cartopy CRS defining the coordinate system of the supplied bbox

    Returns
    -------
    RGB element containing the tile data in the specified bbox
    """