dask-rasterio
dask-rasterio
provides some methods for reading and writing rasters in parallel using Rasterio and Dask arrays.
Usage
Read a multiband raster
>>> from dask_rasterio import read_raster
>>> array = read_raster('tests/data/RGB.byte.tif')
>>> array
dask.array<stack, shape=(3, 718, 791), dtype=uint8, chunksize=(1, 3, 791)>
>>> array.mean()
dask.array<mean_agg-aggregate, shape=(), dtype=float64, chunksize=()>
>>> array.mean().compute()
40.858976977533935
Read a single band from a raster
>>> from dask_rasterio import read_raster
>>> array = read_raster('tests/data/RGB.byte.tif', band=3)
>>> array
dask.array<raster, shape=(718, 791), dtype=uint8, chunksize=(3, 791)>
Write a singleband or multiband raster
>>> from dask_rasterio import read_raster, write_raster
>>> array = read_raster('tests/data/RGB.byte.tif')
>>> new_array = array & (array > 100)
>>> new_array
dask.array<and_, shape=(3, 718, 791), dtype=uint8, chunksize=(1, 3, 791)>
>>> prof = ... # reuse profile from tests/data/RGB.byte.tif...
>>> write_raster('processed_image.tif', new_array, **prof)
Chunk size
Both read_raster
and write_raster
accept a block_size
argument that acts as a multiplier to the block size of rasters. The default value is 1, which means the dask array chunk size will be the same as the block size of the raster file. You will have to adjust this value depending on the specification of your machine (how much memory do you have, and the block size of the raster).
Install
Install with pip:
pip install dask-rasterio
Development
This project is managed by Poetry. If you do not have it installed, please refer to Poetry instructions.
Now, clone the repository and run poetry install
. This will create a virtual environment and install all required packages there.
Run poetry run pytest
to run all tests.
Run poetry build
to build package on dist/
.
Issue tracker
Please report any bugs and enhancement ideas using the GitHub issue tracker:
https://github.com/dymaxionlabs/dask-rasterio/issues
Feel free to also ask questions on our Gitter channel, or by email.
Help wanted
Any help in testing, development, documentation and other tasks is highly appreciated and useful to the project.
For more details, see the file CONTRIBUTING.md.
License
Source code is released under a BSD-2 license. Please refer to LICENSE.md for more information.