feat: add geozarr reader

[vincentsarago]

from obstore.store import HTTPStore
import zarr
from zarr.storage import ObjectStore

from rio_tiler.experimental.zarr import GeoZarrReader

store = HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr/measurements/reflectance")
zarr_store = ObjectStore(store=store, read_only=True)

group = await zarr.api.asynchronous.open_group(store=zarr_store, mode="r")
ds = GeoZarrReader(input=group)

vars = await ds.variables
vars["b02"]

>> [{'array': <AsyncArray object_store://HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr/measurements/reflectance")/r10m/b02 shape=(10980, 10980) dtype=float32>,
  'crs': CRS.from_epsg(32625),
  'height': 10980,
  'width': 10980,
  'transform': Affine(10.0, 0.0, 600000.0,
         0.0, -10.0, 8000040.0)},
 {'array': <AsyncArray object_store://HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr/measurements/reflectance")/r20m/b02 shape=(5490, 5490) dtype=float32>,
  'crs': CRS.from_epsg(32625),
  'height': 5490,
  'width': 5490,
  'transform': Affine(20.0, 0.0, 600000.0,
         0.0, -20.0, 8000040.0)},
 {'array': <AsyncArray object_store://HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr/measurements/reflectance")/r60m/b02 shape=(1830, 1830) dtype=float32>,
  'crs': CRS.from_epsg(32625),
  'height': 1830,
  'width': 1830,
  'transform': Affine(60.0, 0.0, 600000.0,
         0.0, -60.0, 8000040.0)},
 {'array': <AsyncArray object_store://HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr/measurements/reflectance")/r120m/b02 shape=(915, 915) dtype=float32>,
  'crs': CRS.from_epsg(32625),
  'height': 915,
  'width': 915,
  'transform': Affine(120.0, 0.0, 600000.0,
         0.0, -120.0, 8000040.0)},
 {'array': <AsyncArray object_store://HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr/measurements/reflectance")/r360m/b02 shape=(305, 305) dtype=float32>,
  'crs': CRS.from_epsg(32625),
  'height': 305,
  'width': 305,
  'transform': Affine(360.0, 0.0, 600000.0,
         0.0, -360.0, 8000040.0)},
 {'array': <AsyncArray object_store://HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr/measurements/reflectance")/r720m/b02 shape=(152, 152) dtype=float32>,
  'crs': CRS.from_epsg(32625),
  'height': 152,
  'width': 152,
  'transform': Affine(720.0, 0.0, 600000.0,
         0.0, -720.0, 8000040.0)}]

img = await ds.preview(variables="b02", max_size=128)
img 

ImageData(array=masked_array(
  data=[[[0.853752076625824, 0.7639507055282593, 0.7750680446624756,
          ..., 0.2121896743774414, -0.08321993798017502,
          -0.0998888909816742],
         [0.7293742895126343, 0.7273194789886475, 0.8645895719528198,
          ..., 0.919400691986084, 0.642178475856781, 0.2491092085838318],
         [0.8349562287330627, 0.893208384513855, 0.9366021156311035,
          ..., 0.7356111407279968, 0.6698201894760132,
          0.7265465259552002],
         ...,
         [0.9428333044052124, 0.9167847633361816, 0.9088020920753479,
          ..., --, --, --],
         [1.042079210281372, 0.9973312616348267, 0.9550909996032715,
          ..., --, --, --],
         [0.9809249639511108, 1.0116347074508667, 1.052645206451416,
          ..., --, --, --]]],
  mask=[[[False, False, False, ..., False, False, False],
         [False, False, False, ..., False, False, False],
         [False, False, False, ..., False, False, False],
         ...,
         [False, False, False, ...,  True,  True,  True],
         [False, False, False, ...,  True,  True,  True],
         [False, False, False, ...,  True,  True,  True]]],
  fill_value=np.float64(1e+20),
  dtype=float32), assets=[], bounds=BoundingBox(left=600000.0, bottom=7890600.0, right=709440.0, top=8000040.0), crs=CRS.from_epsg(32625), metadata={}, nodata=None, scales=[1.0], offsets=[0.0], band_names=['b1'], band_descriptions=['b1'], dataset_statistics=None, cutline_mask=None, alpha_mask=None)
``

[vincentsarago]

For rio-tiler we need bound and the shape of the dataset to be able to derive the min/max zoom.

This is specific to the tiler usage where the user needs to know where the dataset is and which zoom level they can load the data to before reading the arrays

[vincentsarago]

With latest commits we can now open a root zarr store even If there is not geo metadata

the variables= options should now be in form of {group}:{array}

from obstore.store import HTTPStore
import zarr
from zarr.storage import ObjectStore

from rio_tiler.experimental.zarr import GeoZarrReader

from matplotlib.pyplot import imshow

# Create Obstore Store
store = HTTPStore("https://s3.explorer.eopf.copernicus.eu/esa-zarr-sentinel-explorer-fra/tests-output/sentinel-2-l2a/S2B_MSIL2A_20260216T142149_N0512_R096_T25WFV_20260216T165051.zarr")
zarr_store = ObjectStore(store=store, read_only=True)

# # Get Group and Array
geozarr = await zarr.api.asynchronous.open_group(store=zarr_store, mode="r")

reader = GeoZarrReader(geozarr)
variables = await reader.list_variables()
print(variables)
>>> ['measurements/reflectance:b01', 'measurements/reflectance:b02', 'measurements/reflectance:b03', 'measurements/reflectance:b04', 'measurements/reflectance:b05', 'measurements/reflectance:b06', 'measurements/reflectance:b07', 'measurements/reflectance:b08', 'measurements/reflectance:b09', 'measurements/reflectance:b11', 'measurements/reflectance:b12', 'measurements/reflectance:b8a', 'quality/atmosphere/r10m:aot', 'quality/atmosphere/r10m:wvp', 'quality/atmosphere/r20m:aot', 'quality/atmosphere/r20m:wvp', 'quality/atmosphere/r60m:aot', 'quality/atmosphere/r60m:wvp', 'quality/mask/r10m:b02', 'quality/mask/r10m:b03', 'quality/mask/r10m:b04', 'quality/mask/r10m:b08', 'quality/mask/r20m:b05', 'quality/mask/r20m:b06', 'quality/mask/r20m:b07', 'quality/mask/r20m:b11', 'quality/mask/r20m:b12', 'quality/mask/r20m:b8a', 'quality/mask/r60m:b01', 'quality/mask/r60m:b09', 'quality/mask/r60m:b10', 'quality/probability/r20m:cld', 'quality/probability/r20m:snw']


img = await reader.preview(variables=["measurements/reflectance:b02"], max_size=128)

[vincentsarago]

This is prepping for the future if we can select dimensions within a AsyncArray.

we could in theory have variable being set at {group}:{array}:time=slice(0, 1)