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Due to a conflict between scikit-image and scikit-ued conventions, some breaking changes are required.
Image conventions will now follow that of scikit-image. Most importantly:
* Changed the convention on image masks to align with the scikit-image convention. Masks will be ``True`` for valid pixels, and ``False`` on invalid pixels.
We took the opportunity to make other breaking changes:
* Broke off the ``skued.structure`` package into its own library, ``crystals``.
* Removed `masked_register_translation` in favour of the new scikit-image implementation ported from scikit-ued.
* Removed `xcorr` and `mnxc` as these were the backbone of `masked_register_translation` and are no longer needed.
* Added aspherical electron form factor parametrization from Zheng et al. 2009.
* Removed ``diff_register`` in favor of an analog of scikit-image's `register_translation` and `masked_register_translation`.
* Removed `powder_center` due to unpredictable performance.
* Removed `calibrate_scattvector`, which was deprecated.
* Removed `time_shift` and `time_shifts`, which were deprecated.
* Removed `shift_image` in favor of `scipy.ndimage.shift`.
* `bounded_reflections` has been removed in favor of ``Crystal.bounded_reflections`` in the crystals library (version >= 0.6.4)
We have also added some features:
* Added the `patterson` function to calculate Patterson pair-pair distribution functions from polycrystalline diffraction patterns.
* Added the `detector_scattvectors` function to determine the wavevectors visible on a detector, in transmission,
based on experimental geometry.