Alignment: fixed docstring typos

Signed-off-by: Nicola VIGANÒ <nicola.vigano@esrf.fr>

nabu/preproc/alignment.py

@@ -205,7 +205,8 @@ class AlignmentBase(object):
     def _prepare_image(
         img, invalid_val=1e-5, roi_yxhw=None, median_filt_shape=None, high_pass=None, low_pass=None
     ):
-        """Prepare and returns  a cropped  and filtered image, or array of filtered images if the input is an  array of images.
+        """
+        Prepare and returns  a cropped  and filtered image, or array of filtered images if the input is an  array of images.
 
         Parameters
         ----------
@@ -230,13 +231,11 @@ class AlignmentBase(object):
             When a sequence of two numbers is given then the filter is 1 ( no filtering) till the cutoff
             frequency and then a smooth erfc transition to zero is done
 
-
         Returns
         -------
         numpy.array_like
             The computed filter
         """
-
         img = np.squeeze(img)  # Removes singleton dimensions, but does a shallow copy
         img = np.ascontiguousarray(img)