Merge pull request #280 from nipy/fix/do-not-resample-bsplines

FIX: Remove "densification" of B-Spline transforms in ``apply()``

Author: oesteban

nitransforms/resampling.py

@@ -259,22 +259,14 @@ def apply(
     targets = None
     ref_ndcoords = _ref.ndcoords
 
-    if hasattr(transform, "to_field") and callable(transform.to_field):
-        targets = ImageGrid(spatialimage).index(
-            _as_homogeneous(
-                transform.to_field(reference=reference).map(ref_ndcoords),
-                dim=_ref.ndim,
-            )
-        )
-    else:
-        # Targets' shape is (Nt, 3, Nv) with Nv = Num. voxels, Nt = Num. timepoints.
-        targets = (
-            ImageGrid(spatialimage).index(
-                _as_homogeneous(transform.map(ref_ndcoords), dim=_ref.ndim)
-            )
-            if targets is None
-            else targets
+    # Targets' shape is (Nt, 3, Nv) with Nv = Num. voxels, Nt = Num. timepoints.
+    targets = (
+        ImageGrid(spatialimage).index(
+            _as_homogeneous(transform.map(ref_ndcoords), dim=_ref.ndim)
         )
+        if targets is None
+        else targets
+    )
 
     if targets.ndim == 2:
         targets = targets.T[np.newaxis, ...]