fix: Determine deformation restrictions in the same way as spacing

Author: effigies

sdcflows/workflows/fit/syn.py

@@ -593,25 +593,30 @@ def _remove_first_mask(in_file):
     return workflow
 
 
-def _warp_dir(fixed_image, pe_dir, nlevels=3):
+def _warp_dir(moving_image, fixed_image, pe_dir, nlevels=3):
     """Extract the ``restrict_deformation`` argument from metadata."""
     import numpy as np
     import nibabel as nb
 
-    img = nb.load(fixed_image)
+    moving = nb.load(moving_image)
+    fixed = nb.load(fixed_image)
 
-    if np.any(nb.affines.obliquity(img.affine) > 0.05):
+    if np.any(nb.affines.obliquity(fixed.affine) > 0.05):
         from nipype import logging
 
         logging.getLogger("nipype.interface").warn(
             "Running fieldmap-less registration on an oblique dataset"
         )
 
-    vs = nb.affines.voxel_sizes(img.affine)
-    order = np.around(np.abs(img.affine[:3, :3] / vs))
-    retval = order @ [1 if pe_dir[0] == ax else 0.1 for ax in "ijk"]
+    moving_axcodes = nb.aff2axcodes(moving.affine, ["RR", "AA", "SS"])
+    moving_pe_axis = moving_axcodes["ijk".index(pe_dir[0])]
+
+    fixed_axcodes = nb.aff2axcodes(fixed.affine, ["RR", "AA", "SS"])
+
+    deformation = [0.1, 0.1, 0.1]
+    deformation[fixed_axcodes.index(moving_pe_axis)] = 1.0
 
-    return nlevels * [retval.tolist()]
+    return nlevels * [deformation]
 
 
 def _mm2vox(moving_image, fixed_image, pe_dir, registration_config):