Introducing rasterio

Ever since I wrote Fiona, I've been asked if I have plans to do something similar for geospatial raster data. Having been out of the raster business for a few years, I always said "no serious plans, just blue-sky ideas." Today, I'm back in satellite image processing and very much want and need something like Fiona-for-rasters. Rasterio is my attempt to write such a Python package.

Whereas Fiona is about reading and writing GeoJSON-like objects from and to vector data files, rasterio exists to let Python programmers read and write Numpy arrays (or other array-like objects providing the PEP 3118 buffer interface) from and to raster data files. I intend rasterio to be fast and gotcha-free and let programmers do the things they do now with osgeo.gdal, but with familiar Python idioms and much less code.

I've just uploaded to PyPI rasterio 0.2. Share and enjoy.

Briefly, here's how you use rasterio to get the dimensions, number of bands, indexes of the bands, coordinate reference system, and coordinate transform matrix from a GeoTIFF.

>>> import rasterio
>>> with'rasterio/tests/data/RGB.byte.tif') as src:
...     print(src.width, src.height)
...     print(src.count)
...     print(src.indexes)
...     print(src.dtypes)
...     print(
...     print(src.transform)
(791, 718)
[1, 2, 3]
[<type 'numpy.uint8'>, <type 'numpy.uint8'>, <type 'numpy.uint8'>]
{u'units': u'm', u'no_defs': True, u'ellps': u'WGS84', u'proj': u'utm', u'zone': 18}
[101985.0, 300.0379266750948, 0.0, 2826915.0, 0.0, -300.041782729805]

Rasterio subscribes to PROJ.4 style dicts for coordinate reference systems, as Fiona does. The indexes attribute contains the indexes of all image bands, and those are used to access bands and analyze them like so.

>>> with'rasterio/tests/data/RGB.byte.tif') as src:
...     npixels = src.width * src.height
...     for i in src.indexes:
...         band = src.read_band(i)
...         print(i, band.min(), band.max(), band.sum()/npixels)
(1, 0, 255, 29.94772668847656)
(2, 0, 255, 44.516147889382289)
(3, 0, 255, 48.113056354742945)

Rasterio is written using Cython, so it's fast and has Python 2/3 compatibility. I'm testing with Python 2.7 and Python 3.3 and have it deployed on Python 2.7 at work (where the benchmarks are very positive). I hope you'll find rasterio interesting and follow or fork.