The 'reproject' package is a Python package to reproject astronomical images using various techniques via a uniform interface. By reprojection, we mean the re-gridding of images from one world coordinate system to another (for example changing the pixel resolution, orientation, coordinate system). Currently, we have implemented reprojection of celestial images by interpolation (like SWARP), as well as by finding the exact overlap between pixels on the celestial sphere (like Montage). It can also reproject to/from HEALPIX projections by relying on the healpy package.
For more information, including on how to install the package, see http://reproject.readthedocs.org
The code in this package is released under the BSD license. However, the functions relating to HEALPIX rely on the healpy package, which is GPLv2, so if you use these functions in your code, you are indirectly using healpy and therefore will need to abide with the GPLv2 license.