Pre-Registration Evaluation
===========================

Orders the given stacks by likelihood of yielding a successful alignment when using phase-cross-correlation to align by translation

.. image:: img/2D_preeval.png

Parameters
----------

image_stacks
    Image stacks as a dictionary of numpy arrays or list of HDF5 dataset URI's

reference_stack
    Most relevant stack name

Outputs
-------

image_stacks
    Dictionary of image stacks (HDF5 or numpy) that require the same alignment

reference_stack
    Most relevant stack name

ranked_stack_names
    Stack names ordered from most to least relevant

.. ewokstasks:: ewoksndreg.tasks.reg2d_preeval
    :task-type: class

Notes
-----

This ranking is only relevant for images requiring translations and does not have meaningful output in other cases.

The ranking is based on the phase-cross-correlation algorithm. 
The cross-correlogram between the first and every other image is calculated, which has a peak corresponding to the shift between the images.
By taking the ratio of the peak value and the mean, we can examine how sure this method would be and how much the two images correspond to a pure translation