reproject.reproject_exact(input_data, output_projection, shape_out=None, hdu_in=0, parallel=False, return_footprint=True)[source]

Reproject data to a new projection using flux-conserving spherical polygon intersection (this is the slowest algorithm).


The input data to reproject. This can be:

  • The name of a FITS file

  • An HDUList object

  • An image HDU object such as a PrimaryHDU, ImageHDU, or CompImageHDU instance

  • A tuple where the first element is a ndarray and the second element is either a WCS or a Header object

  • An NDData object from which the .data and .wcs attributes will be used as the input data.

output_projectionWCS or Header

The output projection, which can be either a WCS or a Header instance.

shape_outtuple, optional

If output_projection is a WCS instance, the shape of the output data should be specified separately.

hdu_inint or str, optional

If input_data is a FITS file or an HDUList instance, specifies the HDU to use.

parallelbool or int

Flag for parallel implementation. If True, a parallel implementation is chosen, the number of processes selected automatically to be equal to the number of logical CPUs detected on the machine. If False, a serial implementation is chosen. If the flag is a positive integer n greater than one, a parallel implementation using n processes is chosen.


Whether to return the footprint in addition to the output array.


The reprojected array


Footprint of the input array in the output array. Values of 0 indicate no coverage or valid values in the input image, while values of 1 indicate valid values. Intermediate values indicate partial coverage.