Working With Algorithms¶

For this demo we will use some elevation data from https://www.swisstopo.admin.ch/fr/geodata/height/alti3d.html dataset

Requirements¶

• folium
• httpx

!pip install folium httpx

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import json
import httpx

from folium import Map, TileLayer

import json import httpx from folium import Map, TileLayer

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titiler_endpoint = (
    "https://titiler.xyz"  # Developmentseed Demo endpoint. Please be kind.
)

titiler_endpoint = ( "https://titiler.xyz" # Developmentseed Demo endpoint. Please be kind. )

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url = "https://data.geo.admin.ch/ch.swisstopo.swissalti3d/swissalti3d_2019_2573-1085/swissalti3d_2019_2573-1085_0.5_2056_5728.tif"

url = "https://data.geo.admin.ch/ch.swisstopo.swissalti3d/swissalti3d_2019_2573-1085/swissalti3d_2019_2573-1085_0.5_2056_5728.tif"

Get COG Info¶

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# Fetch dataset Metadata
r = httpx.get(
    f"{titiler_endpoint}/cog/info",
    params={
        "url": url,
    },
).json()

print(r)

# Fetch dataset Metadata r = httpx.get( f"{titiler_endpoint}/cog/info", params={ "url": url, }, ).json() print(r)

Display Tiles¶

By default, the tiles will be rescaled from min/max from dataset statistics (1615.812 / 2015.09448)

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r = httpx.get(
    f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json",
    params={
        "url": url,
    },
).json()

bounds = r["bounds"]
m = Map(
    location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2),
    zoom_start=r["minzoom"],
)

TileLayer(
    tiles=r["tiles"][0], opacity=1, attr="Office fédéral de topographie swisstopo"
).add_to(m)
m

r = httpx.get( f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json", params={ "url": url, }, ).json() bounds = r["bounds"] m = Map( location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2), zoom_start=r["minzoom"], ) TileLayer( tiles=r["tiles"][0], opacity=1, attr="Office fédéral de topographie swisstopo" ).add_to(m) m

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r = httpx.get(
    f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json",
    params={
        "url": url,
        # rio-tiler cannot rescale automatically the data when using a colormap
        "rescale": "1615.812,2015.09448",
        "colormap_name": "terrain",
    },
).json()

bounds = r["bounds"]
m = Map(
    location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2),
    zoom_start=r["minzoom"],
)

aod_layer = TileLayer(
    tiles=r["tiles"][0], opacity=1, attr="Office fédéral de topographie swisstopo"
)
aod_layer.add_to(m)
m

r = httpx.get( f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json", params={ "url": url, # rio-tiler cannot rescale automatically the data when using a colormap "rescale": "1615.812,2015.09448", "colormap_name": "terrain", }, ).json() bounds = r["bounds"] m = Map( location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2), zoom_start=r["minzoom"], ) aod_layer = TileLayer( tiles=r["tiles"][0], opacity=1, attr="Office fédéral de topographie swisstopo" ) aod_layer.add_to(m) m

Show Available Algorithms¶

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# Fetch algorithms
print("Available algorithm")
print(list(httpx.get(f"{titiler_endpoint}/algorithms").json()))
print()
print("Metadata from `Hillshade` algorithm")
meta = httpx.get(f"{titiler_endpoint}/algorithms/hillshade").json()
print("Inputs")
print(meta["inputs"])
print("Outputs")
print(meta["outputs"])
print("Parameters")
print(meta["parameters"])

# Fetch algorithms print("Available algorithm") print(list(httpx.get(f"{titiler_endpoint}/algorithms").json())) print() print("Metadata from `Hillshade` algorithm") meta = httpx.get(f"{titiler_endpoint}/algorithms/hillshade").json() print("Inputs") print(meta["inputs"]) print("Outputs") print(meta["outputs"]) print("Parameters") print(meta["parameters"])

Display Hillshade Tiles¶

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r = httpx.get(
    f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json",
    params={
        "url": url,
        "algorithm": "hillshade",
        # Hillshade algorithm use a 3pixel buffer so we need
        # to tell the tiler to apply a 3 pixel buffer around each tile
        "buffer": 3,
    },
).json()

bounds = r["bounds"]
m = Map(
    location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2),
    zoom_start=r["minzoom"],
)

aod_layer = TileLayer(tiles=r["tiles"][0], opacity=1, attr="Yo!!")
aod_layer.add_to(m)
m

r = httpx.get( f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json", params={ "url": url, "algorithm": "hillshade", # Hillshade algorithm use a 3pixel buffer so we need # to tell the tiler to apply a 3 pixel buffer around each tile "buffer": 3, }, ).json() bounds = r["bounds"] m = Map( location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2), zoom_start=r["minzoom"], ) aod_layer = TileLayer(tiles=r["tiles"][0], opacity=1, attr="Yo!!") aod_layer.add_to(m) m

Pass parameters to the algorithm¶

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r = httpx.get(
    f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json",
    params={
        "url": url,
        "algorithm": "contours",
        "algorithm_params": json.dumps(
            {
                "increment": 20,  # contour line every 20 meters
                "thickness": 2,  # 2m thickness
                "minz": 1600,
                "maxz": 2000,
            }
        ),
    },
).json()

bounds = r["bounds"]
m = Map(
    location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2),
    zoom_start=r["minzoom"],
)

TileLayer(tiles=r["tiles"][0], opacity=1, attr="Yo!!").add_to(m)
m

r = httpx.get( f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json", params={ "url": url, "algorithm": "contours", "algorithm_params": json.dumps( { "increment": 20, # contour line every 20 meters "thickness": 2, # 2m thickness "minz": 1600, "maxz": 2000, } ), }, ).json() bounds = r["bounds"] m = Map( location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2), zoom_start=r["minzoom"], ) TileLayer(tiles=r["tiles"][0], opacity=1, attr="Yo!!").add_to(m) m

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r = httpx.get(
    f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json",
    params={
        "url": url,
        "algorithm": "contours",
        "algorithm_params": json.dumps(
            {
                "increment": 5,  # contour line every 5 meters
                "thickness": 1,  # 1m thickness
                "minz": 1600,
                "maxz": 2000,
            }
        ),
    },
).json()

bounds = r["bounds"]
m = Map(
    location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2),
    zoom_start=r["minzoom"],
)

TileLayer(tiles=r["tiles"][0], opacity=1, attr="Yo!!").add_to(m)
m

r = httpx.get( f"{titiler_endpoint}/cog/WebMercatorQuad/tilejson.json", params={ "url": url, "algorithm": "contours", "algorithm_params": json.dumps( { "increment": 5, # contour line every 5 meters "thickness": 1, # 1m thickness "minz": 1600, "maxz": 2000, } ), }, ).json() bounds = r["bounds"] m = Map( location=((bounds[1] + bounds[3]) / 2, (bounds[0] + bounds[2]) / 2), zoom_start=r["minzoom"], ) TileLayer(tiles=r["tiles"][0], opacity=1, attr="Yo!!").add_to(m) m

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