Add test case for invalid image dimensions

skimage/transform/_geometric.py

@@ -1025,8 +1025,8 @@ def warp(image, inverse_map=None, map_args={}, output_shape=None, order=1,
                       'the `inverse_map` parameter.')
         inverse_map = reverse_map
 
-    if image.ndim < 2:
-        raise ValueError("Input must have more than 1 dimension.")
+    if image.ndim < 2 or image.ndim > 3:
+        raise ValueError("Input must have 2 or 3 dimensions.")
 
     orig_ndim = image.ndim
     image = np.atleast_3d(img_as_float(image))

skimage/transform/tests/test_warps.py

@@ -1,4 +1,5 @@
-from numpy.testing import assert_array_almost_equal, run_module_suite, assert_array_equal
+from numpy.testing import (assert_array_almost_equal, run_module_suite,
+                           assert_array_equal, assert_raises)
 import numpy as np
 from scipy.ndimage import map_coordinates
 
@@ -234,5 +235,10 @@ def test_downscale_local_mean():
     assert_array_equal(expected2, out2)
 
 
+def test_invalid():
+    assert_raises(ValueError, warp, np.ones((4, )), SimilarityTransform())
+    assert_raises(ValueError, warp, np.ones((4, 3, 3, 3)), SimilarityTransform())
+
+
 if __name__ == "__main__":
     run_module_suite()