https://github.com/developmentseed/mosaicjson-spec
JSON format for describing SpatioTemporal Cloud Optimized Geotiff mosaic.
https://github.com/developmentseed/mosaicjson-spec
Last synced: 10 months ago
JSON representation
JSON format for describing SpatioTemporal Cloud Optimized Geotiff mosaic.
- Host: GitHub
- URL: https://github.com/developmentseed/mosaicjson-spec
- Owner: developmentseed
- License: mit
- Created: 2019-03-26T14:56:40.000Z (about 7 years ago)
- Default Branch: main
- Last Pushed: 2023-06-03T20:43:00.000Z (almost 3 years ago)
- Last Synced: 2024-04-10T03:11:37.752Z (about 2 years ago)
- Homepage:
- Size: 22.5 KB
- Stars: 73
- Watchers: 12
- Forks: 6
- Open Issues: 1
-
Metadata Files:
- Readme: Readme.md
- Changelog: CHANGES.md
- License: LICENSE
Awesome Lists containing this project
README
MosaicJSON is an open standard for representing
metadata about a mosaic of Assets (e.g Cloud Optimized GeoTIFF).
---
**Blog Post**: https://medium.com/devseed/cog-talk-part-2-mosaics-bbbf474e66df
**Source Code**: https://github.com/developmentseed/mosaicjson-spec
---
## Description
MosaicJSON can be seen as a Virtual raster (see GDAL's [VRT](https://gdal.org/drivers/raster/vrt.html)) enabling spatial and temporal processing for a list of **Assets**.
## Features
- simple **JSON** format (enabling high ratio compression)
- **quadkey** based file index
## Implementations
[cogeo-mosaic](https://github.com/developmentseed/cogeo-mosaic)
## API Example
```python
def fetch_mosaic_definition(url: Union[str, Path]) -> Dict:
"""Fetch mosaic definition file."""
...
return mosaic_definition
def _fetch_and_find_asset(url: str, x: int, y: int, z: int):
mdef = fetch_mosaic_definition(url)
return get_assets(mdef, x: int, y: int, z: int)
def get_assets(mosaic_definition: Dict, x: int, y: int, z: int) -> list[str]:
"""Get asset list for a Z/X/Y index and a mosaic definition.
Parameters
----------
mosaic_definition : dict
mosaic definition content.
x : int
Mercator tile X index.
y : int
Mercator tile Y index.
z : int
Mercator tile ZOOM level.
Returns
-------
assets : list
list of assets intersecting with the tile index.
"""
min_zoom = mosaic_definition["minzoom"]
mercator_tile = mercantile.Tile(x=x, y=y, z=z)
quadkey_zoom = mosaic_definition.get("quadkey_zoom", min_zoom) # 0.0.2
# get parent
if mercator_tile.z > quadkey_zoom:
depth = mercator_tile.z - quadkey_zoom
for i in range(depth):
mercator_tile = mercantile.parent(mercator_tile)
quadkey = [mercantile.quadkey(*mercator_tile)]
# get child
elif mercator_tile.z < quadkey_zoom:
depth = quadkey_zoom - mercator_tile.z
mercator_tiles = [mercator_tile]
for i in range(depth):
mercator_tiles = sum([mercantile.children(t) for t in mercator_tiles], [])
mercator_tiles = list(filter(lambda t: t.z == quadkey_zoom, mercator_tiles))
quadkey = [mercantile.quadkey(*tile) for tile in mercator_tiles]
else:
quadkey = [mercantile.quadkey(*mercator_tile)]
assets = list(
itertools.chain.from_iterable(
[mosaic_definition["tiles"].get(qk, []) for qk in quadkey]
)
)
# check if we have a mosaic in the url (.json/.gz)
return list(
itertools.chain.from_iterable(
[
fetch_and_find_assets(asset, x, y, z)
if os.path.splitext(asset)[1] in [".json", ".gz"]
else [asset]
for asset in assets
]
)
)
```
## License
The text of this specification is licensed under the
[MIT License](https://github.com/developmentseed/mosaicjson-spec/blob/main/LICENSE).
The use of this spec in products and code is entirely free:
there are no royalties, restrictions, or requirements.
## Authors
* Vincent Sarago
* Sean Harkins
* Drew Bollinger