diff --git a/sima/motion/dftreg.py b/sima/motion/dftreg.py
index f0962e4..ba2b14c 100644
--- a/sima/motion/dftreg.py
+++ b/sima/motion/dftreg.py
@@ -36,6 +36,7 @@
 import numpy as np
 from scipy.ndimage.interpolation import shift
 import time
+import warnings
 from . import motion
 try:
     from pyfftw.interfaces.numpy_fft import fftn, ifftn
@@ -123,11 +124,13 @@ def _estimate(self, dataset):
         displacements = []
 
         for sequence in dataset:
-            num_planes = sequence.shape[1]
-            num_channels = sequence.shape[4]
+            num_frames, num_planes, _, _, num_channels = sequence.shape
             if num_channels > 1:
-                raise NotImplementedError("Error: only one colour channel \
-                    can be used for DFT motion correction. Using channel 1.")
+                warnings.warn("Warning: only one colour channel \
+                    can be used for DFT motion correction. Using channel 0.")
+
+            # get results into a shape sima likes
+            frame_shifts = np.zeros([num_frames, num_planes, 2])
 
             for plane_idx in range(num_planes):
                 # load into memory... need to pass numpy array to dftreg.
@@ -172,8 +175,7 @@ def _estimate(self, dataset):
                 else:
                     dy, dx = output
 
-                # get results into a shape sima likes
-                frame_shifts = np.zeros([len(frames), num_planes, 2])
+                # add plane shift info
                 for idx, frame in enumerate(sequence):
                     frame_shifts[idx, plane_idx] = [dy[idx], dx[idx]]
             displacements.append(frame_shifts)
diff --git a/sima/motion/motion.py b/sima/motion/motion.py
index 4d667e9..a6d7e63 100644
--- a/sima/motion/motion.py
+++ b/sima/motion/motion.py
@@ -121,6 +121,11 @@ def correct(self, dataset, savedir, channel_names=None, info=None,
         else:
             mc_sequences = sequences
         displacements = self.estimate(sima.ImagingDataset(mc_sequences, None))
+
+        # enforce integer displacements
+        displacements = [d if issubclass(d.dtype.type, np.integer) else \
+                         d.round().astype(np.int64) for d in displacements]
+
         disp_dim = displacements[0].shape[-1]
         max_disp = np.ceil(
             np.max(list(it.chain.from_iterable(d.reshape(-1, disp_dim)
@@ -188,7 +193,17 @@ def _estimate(self, dataset):
             downsampled_dataset)
         displacements = []
         for d_disps in downsampled_displacements:
-            disps = np.repeat(d_disps, 2, axis=2)  # Repeat the displacements
+            if d_disps.ndim == 3: # whole frame displacements
+                if self._offset == 0:
+                    disps = d_disps[:]
+                    disps[..., 0] *= 2 # multiply y-shifts by 2
+                    displacements.append(disps)
+                    continue
+                else: # duplicate displacements for all rows
+                    disps = np.moveaxis(np.stack(
+                        [d_disps] * dataset.frame_shape[0]), 0, 2)
+            else: # line-by-line displacements
+                disps = np.repeat(d_disps, 2, axis=2)  # Repeat the displacements
             disps[:, :, :, 0] *= 2  # multiply y-shifts by 2
             disps[:, :, 1::2, -1] += self._offset  # shift even rows by offset
             displacements.append(disps)