diff --git a/skimage/feature/censure.py b/skimage/feature/censure.py
index 996f7e16..d52583c2 100644
--- a/skimage/feature/censure.py
+++ b/skimage/feature/censure.py
@@ -192,11 +192,7 @@ def keypoints_censure(image, min_scale=1, max_scale=7, mode='DoB',
     if image.ndim != 2:
         raise ValueError("Only 2-D gray-scale images supported.")
 
-    image = img_as_float(image)
-    image = np.ascontiguousarray(image)
-
     mode = mode.lower()
-
     if mode not in ('dob', 'octagon', 'star'):
         raise ValueError('Mode must be one of "DoB", "Octagon", "STAR".')
 
@@ -204,6 +200,9 @@ def keypoints_censure(image, min_scale=1, max_scale=7, mode='DoB',
         raise ValueError('The number of scales should be greater than or'
                          'equal to 3.')
 
+    image = img_as_float(image)
+    image = np.ascontiguousarray(image)
+
     # Generating all the scales
     filter_response = _get_filtered_image(image, min_scale, max_scale, mode)
 
diff --git a/skimage/feature/tests/test_censure.py b/skimage/feature/tests/test_censure.py
index 26555697..4cd2ad68 100644
--- a/skimage/feature/tests/test_censure.py
+++ b/skimage/feature/tests/test_censure.py
@@ -10,6 +10,20 @@ def test_keypoints_censure_color_image_unsupported_error():
     assert_raises(ValueError, keypoints_censure, img)
 
 
+def test_keypoints_censure_mode_validity_error():
+    """Mode argument in keypoints_censure can be either DoB, Octagon or
+    STAR."""
+    img = np.zeros((20, 20))
+    assert_raises(ValueError, keypoints_censure, img, mode='dummy')
+
+
+def test_keypoints_censure_scale_range_error():
+    """Difference between the the max_scale and min_scale parameters in
+    keypoints_censure should be greater than or equal to two."""
+    img = np.zeros((20, 20))
+    assert_raises(ValueError, keypoints_censure, img, min_scale=1, max_scale=2)
+
+
 def test_keypoints_censure_moon_image_dob():
     """Verify the actual Censure keypoints and their corresponding scale with
     the expected values for DoB filter."""