Tile serving example with FastAPI #3

banesullivan · 2022-07-27T23:23:47Z

banesullivan
Jul 27, 2022
Maintainer

This is a simple example to show how easy dynamic tile serving can be with large-image - this is effectively all that localtileserver does

import io

from fastapi import FastAPI
from ipyleaflet import Map, TileLayer
import large_image
from starlette.responses import StreamingResponse

from server_thread import ServerThread

src = large_image.open(
    "/Users/bane/Desktop/rasters/TC_NG_SFBay_US_Geo.tif", projection="EPSG:3857", encoding="PNG"
)

app = FastAPI()


@app.get("/metadata")
async def get_metadata():
    return src.getMetadata()


@app.get("/tile/{z}/{x}/{y}.png")
async def get_tile(z: int, x: int, y: int):
    tile_binary = src.getTile(x, y, z)
    return StreamingResponse(io.BytesIO(tile_binary), media_type="image/png")


# Launch app in a background thread
server = ServerThread(app)

t = TileLayer(
    url=f"http://{server.host}:{server.port}/tile/{{z}}/{{x}}/{{y}}.png",
    attribution="booya!",
)

m = Map(zoom=8, center=[37.8751050766018, -122.19290725886823])
m.add_layer(t)
m