Add test that the 2D results correspond to scipy's

Remove trailing whitespace

skimage/morphology/misc.py

@@ -8,15 +8,16 @@ funcs = ('erosion', 'dilation', 'opening', 'closing')
 skimage2ndimage = {x: 'grey_' + x for x in funcs}
 
 # These function names are the same in ndimage.
-funcs = ('binary_erosion', 'binary_dilation', 'binary_opening', 
+funcs = ('binary_erosion', 'binary_dilation', 'binary_opening',
          'binary_closing', 'black_tophat', 'white_tophat')
 skimage2ndimage.update({x: x for x in funcs})
 
 def default_fallback(func):
     """Decorator to fall back on ndimage for images with more than 2 dimensions
+
     Decorator also provides a default structuring element, `selem`, with the
     appropriate dimensionality if none is specified.
-    
+
     Parameters
     ----------
     func : function
@@ -29,7 +30,7 @@ def default_fallback(func):
         If the image dimentionality is greater than 2D, the ndimage
         function is returned, otherwise skimage function is used.
     """
-    
+
     def func_out(image, selem=None, out=None, **kwargs):
         # Default structure element
         if selem is None:

skimage/morphology/tests/test_binary.py

@@ -110,26 +110,42 @@ def test_3d_fallback_cube_selem():
         new_image = function(image, cube)
         yield testing.assert_array_equal, new_image, image
 
+def test_2d_ndimage_equivalence():
+    image = np.zeros((9, 9), np.uint16)
+    image[2:-2, 2:-2] = 2**14
+    image[3:-3, 3:-3] = 2**15
+    image[4, 4] = 2**16-1
+
+    bin_opened = binary.binary_opening(image)
+    bin_closed = binary.binary_closing(image)
+
+    selem = ndimage.generate_binary_structure(2, 1)
+    ndimage_opened = ndimage.binary_opening(image, structure=selem)
+    ndimage_closed = ndimage.binary_closing(image, structure=selem)
+
+    testing.assert_array_equal(bin_opened, ndimage_opened)
+    testing.assert_array_equal(bin_closed, ndimage_closed)
+
 def test_binary_output_2d():
     image = np.zeros((9, 9), np.uint16)
     image[2:-2, 2:-2] = 2**14
     image[3:-3, 3:-3] = 2**15
     image[4, 4] = 2**16-1
-    
+
     bin_opened = binary.binary_opening(image)
     bin_closed = binary.binary_closing(image)
-    
+
     int_opened = np.empty_like(image, dtype=np.uint8)
     int_closed = np.empty_like(image, dtype=np.uint8)
     binary.binary_opening(image, out=int_opened)
     binary.binary_closing(image, out=int_closed)
-    
+
     testing.assert_equal(bin_opened.dtype, np.bool)
     testing.assert_equal(bin_closed.dtype, np.bool)
-    
+
     testing.assert_equal(int_opened.dtype, np.uint8)
     testing.assert_equal(int_closed.dtype, np.uint8)
- 
+
 def test_binary_output_3d():
     image = np.zeros((9, 9, 9), np.uint16)
     image[2:-2, 2:-2, 2:-2] = 2**14
@@ -138,17 +154,17 @@ def test_binary_output_3d():
 
     bin_opened = binary.binary_opening(image)
     bin_closed = binary.binary_closing(image)
-    
+
     int_opened = np.empty_like(image, dtype=np.uint8)
     int_closed = np.empty_like(image, dtype=np.uint8)
     binary.binary_opening(image, out=int_opened)
     binary.binary_closing(image, out=int_closed)
-    
+
     testing.assert_equal(bin_opened.dtype, np.bool)
     testing.assert_equal(bin_closed.dtype, np.bool)
-    
+
     testing.assert_equal(int_opened.dtype, np.uint8)
-    testing.assert_equal(int_closed.dtype, np.uint8)   
+    testing.assert_equal(int_closed.dtype, np.uint8)
 
 if __name__ == '__main__':
     testing.run_module_suite()

skimage/morphology/tests/test_grey.py

@@ -175,7 +175,7 @@ def test_3d_fallback_white_tophat():
     footprint = ndimage.generate_binary_structure(3,1)
     image_expected = ndimage.white_tophat(image,footprint=footprint)
     testing.assert_array_equal(new_image, image_expected)
-    
+
 def test_3d_fallback_black_tophat():
     image = np.ones((7, 7, 7), dtype=bool)
     image[2, 2:4, 2:4] = 0
@@ -186,6 +186,22 @@ def test_3d_fallback_black_tophat():
     image_expected = ndimage.black_tophat(image,footprint=footprint)
     testing.assert_array_equal(new_image, image_expected)
 
+def test_2d_ndimage_equivalence():
+    image = np.zeros((9, 9), np.uint16)
+    image[2:-2, 2:-2] = 2**14
+    image[3:-3, 3:-3] = 2**15
+    image[4, 4] = 2**16-1
+
+    opened = grey.opening(image)
+    closed = grey.closing(image)
+
+    selem = ndimage.generate_binary_structure(2, 1)
+    ndimage_opened = ndimage.grey_opening(image, structure=selem)
+    ndimage_closed = ndimage.grey_closing(image, structure=selem)
+
+    testing.assert_array_equal(opened, ndimage_opened)
+    testing.assert_array_equal(closed, ndimage_closed)
+
 class TestDTypes():
 
     def setUp(self):