Alignment: fixed bug due to out-dated variable content

Thanks Alessandro for spotting this
Signed-off-by: Nicola VIGANÒ <nicola.vigano@esrf.fr>

nabu/preproc/alignment.py

@@ -514,6 +514,7 @@ class CenterOfRotation(AlignmentBase):
         img_2 = self._prepare_image(img_2, roi_yxhw=roi_yxhw, median_filt_shape=median_filt_shape)
 
         cc = self._compute_correlation_fft(img_1, img_2, padding_mode, high_pass=high_pass, low_pass=low_pass)
+
         img_shape = img_2.shape
         cc_vs = np.fft.fftfreq(img_shape[-2], 1 / img_shape[-2])
         cc_hs = np.fft.fftfreq(img_shape[-1], 1 / img_shape[-1])
@@ -628,9 +629,6 @@ class DetectorTranslationAlongBeam(AlignmentBase):
 
         img_stack = self._prepare_image(img_stack, roi_yxhw=roi_yxhw, median_filt_shape=median_filt_shape)
 
-        cc_vs = np.fft.fftfreq(img_shape[-2], 1 / img_shape[-2])
-        cc_hs = np.fft.fftfreq(img_shape[-1], 1 / img_shape[-1])
-
         # do correlations
         ccs = [
             self._compute_correlation_fft(
@@ -643,6 +641,10 @@ class DetectorTranslationAlongBeam(AlignmentBase):
             for ii in range(1, num_imgs)
         ]
 
+        img_shape = img_stack.shape[-2:]
+        cc_vs = np.fft.fftfreq(img_shape[-2], 1 / img_shape[-2])
+        cc_hs = np.fft.fftfreq(img_shape[-1], 1 / img_shape[-1])
+
         shifts_vh = np.empty((num_imgs - 1, 2))
         for ii, cc in enumerate(ccs):
             (f_vals, fv, fh) = self.extract_peak_region_2d(cc, peak_radius=peak_fit_radius, cc_vs=cc_vs, cc_hs=cc_hs)