Get statistics of a derived band (e.g., NDVI) #429
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How to get the statistics of a derived band (e.g., NDVI). For this sample dataset, NDVI= https://developmentseed.org/titiler/endpoints/stac/#statistics import requests
titiler_endpoint = "https://titiler.xyz"
url = "https://canada-spot-ortho.s3.amazonaws.com/canada_spot_orthoimages/canada_spot5_orthoimages/S5_2007/S5_11055_6057_20070622/S5_11055_6057_20070622.json"
params = {
'url': url,
'assets': ['B4', 'B3']
}
r = requests.get(f"{titiler_endpoint}/stac/statistics", params=params).json()
r |
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Replies: 3 comments 3 replies
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@giswqs you are right, this features has been remove in rio-tiler 3.0 (so in titiler 4.0) because it was complex and didn't fit with the new definition of the function. It will pretty simple for someone to create a custom endpoint from fastapi import FastAPI, Depends
from titiler.core.factory import MultiBaseTilerFactory
from titiler.core.dependencies import AssetsBidxExprParams
from titiler.core.models.responses import Statistics
from rio_tiler.io import STACReader
from rio_tiler.models import BandStatistics
app = FastAPI()
# Create a Default set of endpoint using the MultiBaseTilerFactory
stac = MultiBaseTilerFactory(reader=STACReader)
# GET endpoint
@stac.router.get(
"/advanced_statistics",
response_class=JSONResponse,
response_model=Statistics,
responses={
200: {
"content": {"application/json": {}},
"description": "Return dataset's statistics.",
}
},
)
def statistics(
src_path=Depends(stac.path_dependency),
asset_params=Depends(AssetsBidxExprParams),
dataset_params=Depends(stac.dataset_dependency),
image_params=Depends(stac.img_dependency),
stats_params=Depends(stac.stats_dependency),
histogram_params=Depends(stac.histogram_dependency),
):
with rasterio.Env(**self.gdal_config):
with self.reader(src_path) as src_dst:
data = src_dst.preview(
**asset_params,
**dataset_params,
**image_params,
)
stats = get_array_statistics(
data.as_masked(),
**stats_params,
hist_options={**histogram_params},
)
return {
f"{data.band_names[ix]}": BandStatistics(**stats[ix])
for ix in range(len(stats))
}
app.include_router(cog.router) |
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@vincentsarago Thanks for sharing the script for creating a custom endpoint. The reason I wanted the statistics of a derived band is to get the @TomAugspurger Just want to keep in the loop in case you run into this problem later. I have updated leafmap and the notebook exmaple. It works fine with the latest Planetary Computer Data API. |
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Thanks @giswqs. I've confirmed that things are working properly with the most recent version of leafmap and the PC's data API. By the way, our next release will move some rendering configuration to our API. Currently, that's stored in our frontend explorer, which is what knows to take a user selection of "Natural Color" at https://planetarycomputer.microsoft.com/explore?c=124.0274%2C-16.4940&z=9.00&d=sentinel-2-l2a&m=Most+recent+%28low+cloud%29 and translate it into a query like for images like
Hopefully once that's ready, we can get some good presets / defaults into leafmap, so that users can do something like m.add_stac_item(collection=collection, item=item, render="natural color")and users won't need to worry about selecting assets, expressions, rescaling, etc. |
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Great to know. I will look into the new API and make changes to leafmap accordingly |
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I just released titiler==0.5.0 which revert the |
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This is great! Thank you. |
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I just released titiler==0.5.0 which revert the
/stac/statisticsendpoint to something that should be compatible with the previous usage (using expression). Thestatisticsendpoint from0.4is now calledasset_statistics.