Test invalid input for seed

skimage/morphology/tests/test_reconstruction.py

@@ -8,7 +8,8 @@ All rights reserved.
 Original author: Lee Kamentsky
 """
 import numpy as np
-from numpy.testing import assert_array_almost_equal as assert_close
+from numpy.testing import (assert_array_almost_equal as assert_close,
+                           assert_raises)
 
 from skimage.morphology.greyreconstruct import reconstruction
 
@@ -77,6 +78,15 @@ def test_fill_hole():
     assert_close(result, np.array([0, 3, 6, 4, 4, 4, 4, 4, 2, 0]))
 
 
+def test_invalid_seed():
+    seed = np.ones((5, 5))
+    mask = np.ones((5, 5))
+    assert_raises(ValueError, reconstruction, seed * 2, mask,
+                  method='dilation')
+    assert_raises(ValueError, reconstruction, seed * 0.5, mask,
+                  method='erosion')
+
+
 if __name__ == '__main__':
     from numpy import testing
     testing.run_module_suite()