combine_images

sofia_redux.toolkit.image.combine.combine_images(data, variance=None, method='median', weighted=True, robust=True, returned=True, **kwargs)

Combine input image arrays.

Uses masked arrays to ignore input NaNs and to clip outliers if necessary. Masked pixels in the output are replaced with NaN before returning.

Parameters:

datalist of numpy.ndarray or numpy.ndarray

Input data to combine. Dimensions must match for all arrays. If ndarray is provided, images will be combined along axis 0.

variancelist of numpy.ndarray or numpy.ndarray, optional

Variance associated with input data. List length and features must match data.

method{‘mean’, ‘median’, ‘sum’}, optional

Combination function to use.

weightedbool, optional

If True and method is ‘mean’, the input variance will be used to weight the mean combination. Ignored if variance is not provided.

robustbool, optional

If True, the threshold and maxiters parameters will be used to reject outliers before combination. Outlier rejection is performed via astropy.stats.sigma_clip.

returnedbool, optional

If True, return the combined variance in addition to the combined image. Variance will be propagated if provided, or calculated from the RMS of each pixel over all images.

**kwargs

Additional parameters to pass to astropy.stats.sigma_clip when robust=True. ‘axis’ and ‘masked’ keywords are ignored if provided.

Returns:

tuple of numpy.ndarray

Return value is (data, variance) for the combined array. If input variance is provided, it is propagated; otherwise, the returned variance is calculated from the input data.

Raises:

ValueError

Any improper inputs.