From bb732c922585073645a444dcbbccfcdf3969b744 Mon Sep 17 00:00:00 2001
From: Nelson Brown <nelson.brown@gmail.com>
Date: Fri, 11 Jul 2014 13:50:55 -0700
Subject: [PATCH 1/6] Add default structuring element to morphology

---
 skimage/morphology/binary.py            | 19 +++++++---
 skimage/morphology/grey.py              | 46 ++++++++++++++++++++-----
 skimage/morphology/selem.py             | 21 +++++++++++
 skimage/morphology/tests/test_binary.py | 25 ++++++++++++++
 skimage/morphology/tests/test_grey.py   | 26 ++++++++++++++
 5 files changed, 124 insertions(+), 13 deletions(-)

diff --git a/skimage/morphology/binary.py b/skimage/morphology/binary.py
index 24c5c0ea..636717af 100644
--- a/skimage/morphology/binary.py
+++ b/skimage/morphology/binary.py
@@ -1,9 +1,10 @@
 import warnings
 import numpy as np
 from scipy import ndimage
+from .selem import _default_selem
 
 
-def binary_erosion(image, selem, out=None):
+def binary_erosion(image, selem=None, out=None):
     """Return fast binary morphological erosion of an image.
 
     This function returns the same result as greyscale erosion but performs
@@ -29,6 +30,11 @@ def binary_erosion(image, selem, out=None):
         The result of the morphological erosion with values in ``[0, 1]``.
 
     """
+    
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+        
     selem = (selem != 0)
     selem_sum = np.sum(selem)
 
@@ -45,7 +51,7 @@ def binary_erosion(image, selem, out=None):
     return np.equal(conv, selem_sum, out=out)
 
 
-def binary_dilation(image, selem, out=None):
+def binary_dilation(image, selem=None, out=None):
     """Return fast binary morphological dilation of an image.
 
     This function returns the same result as greyscale dilation but performs
@@ -72,6 +78,11 @@ def binary_dilation(image, selem, out=None):
         The result of the morphological dilation with values in ``[0, 1]``.
 
     """
+    
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+        
     selem = (selem != 0)
 
     if np.sum(selem) <= 255:
@@ -87,7 +98,7 @@ def binary_dilation(image, selem, out=None):
     return np.not_equal(conv, 0, out=out)
 
 
-def binary_opening(image, selem, out=None):
+def binary_opening(image, selem=None, out=None):
     """Return fast binary morphological opening of an image.
 
     This function returns the same result as greyscale opening but performs
@@ -119,7 +130,7 @@ def binary_opening(image, selem, out=None):
     return out
 
 
-def binary_closing(image, selem, out=None):
+def binary_closing(image, selem=None, out=None):
     """Return fast binary morphological closing of an image.
 
     This function returns the same result as greyscale closing but performs
diff --git a/skimage/morphology/grey.py b/skimage/morphology/grey.py
index 13e9dfbb..7fb1c8c9 100644
--- a/skimage/morphology/grey.py
+++ b/skimage/morphology/grey.py
@@ -1,5 +1,8 @@
 import warnings
 from skimage import img_as_ubyte
+from scipy import ndimage
+from .selem import _default_selem
+
 
 from . import cmorph
 
@@ -8,7 +11,7 @@ __all__ = ['erosion', 'dilation', 'opening', 'closing', 'white_tophat',
            'black_tophat']
 
 
-def erosion(image, selem, out=None, shift_x=False, shift_y=False):
+def erosion(image, selem=None, out=None, shift_x=False, shift_y=False):
     """Return greyscale morphological erosion of an image.
 
     Morphological erosion sets a pixel at (i,j) to the minimum over all pixels
@@ -21,7 +24,7 @@ def erosion(image, selem, out=None, shift_x=False, shift_y=False):
         Image array.
     selem : ndarray
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray
+    out : ndarrays
         The array to store the result of the morphology. If None is
         passed, a new array will be allocated.
     shift_x, shift_y : bool
@@ -52,6 +55,10 @@ def erosion(image, selem, out=None, shift_x=False, shift_y=False):
 
     """
 
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+        
     if image is out:
         raise NotImplementedError("In-place erosion not supported!")
     image = img_as_ubyte(image)
@@ -60,7 +67,7 @@ def erosion(image, selem, out=None, shift_x=False, shift_y=False):
                          shift_x=shift_x, shift_y=shift_y)
 
 
-def dilation(image, selem, out=None, shift_x=False, shift_y=False):
+def dilation(image, selem=None, out=None, shift_x=False, shift_y=False):
     """Return greyscale morphological dilation of an image.
 
     Morphological dilation sets a pixel at (i,j) to the maximum over all pixels
@@ -105,6 +112,10 @@ def dilation(image, selem, out=None, shift_x=False, shift_y=False):
 
     """
 
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+    
     if image is out:
         raise NotImplementedError("In-place dilation not supported!")
     image = img_as_ubyte(image)
@@ -113,7 +124,7 @@ def dilation(image, selem, out=None, shift_x=False, shift_y=False):
                           shift_x=shift_x, shift_y=shift_y)
 
 
-def opening(image, selem, out=None):
+def opening(image, selem=None, out=None):
     """Return greyscale morphological opening of an image.
 
     The morphological opening on an image is defined as an erosion followed by
@@ -154,7 +165,11 @@ def opening(image, selem, out=None):
            [0, 0, 0, 0, 0]], dtype=uint8)
 
     """
-
+    
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+        
     h, w = selem.shape
     shift_x = True if (w % 2) == 0 else False
     shift_y = True if (h % 2) == 0 else False
@@ -164,7 +179,7 @@ def opening(image, selem, out=None):
     return out
 
 
-def closing(image, selem, out=None):
+def closing(image, selem=None, out=None):
     """Return greyscale morphological closing of an image.
 
     The morphological closing on an image is defined as a dilation followed by
@@ -206,6 +221,10 @@ def closing(image, selem, out=None):
 
     """
 
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+    
     h, w = selem.shape
     shift_x = True if (w % 2) == 0 else False
     shift_y = True if (h % 2) == 0 else False
@@ -215,7 +234,7 @@ def closing(image, selem, out=None):
     return out
 
 
-def white_tophat(image, selem, out=None):
+def white_tophat(image, selem=None, out=None):
     """Return white top hat of an image.
 
     The white top hat of an image is defined as the image minus its
@@ -254,7 +273,12 @@ def white_tophat(image, selem, out=None):
            [0, 0, 1, 0, 0],
            [0, 0, 0, 0, 0]], dtype=uint8)
 
-   """
+    """
+   
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+        
     if image is out:
         raise NotImplementedError("Cannot perform white top hat in place.")
 
@@ -263,7 +287,7 @@ def white_tophat(image, selem, out=None):
     return out
 
 
-def black_tophat(image, selem, out=None):
+def black_tophat(image, selem=None, out=None):
     """Return black top hat of an image.
 
     The black top hat of an image is defined as its morphological closing minus
@@ -305,6 +329,10 @@ def black_tophat(image, selem, out=None):
 
     """
 
+    # Default structure element
+    if selem is None:
+        selem = _default_selem(image.ndim)
+        
     if image is out:
         raise NotImplementedError("Cannot perform white top hat in place.")
 
diff --git a/skimage/morphology/selem.py b/skimage/morphology/selem.py
index 7e566773..24adfce6 100644
--- a/skimage/morphology/selem.py
+++ b/skimage/morphology/selem.py
@@ -4,6 +4,7 @@
 """
 
 import numpy as np
+from scipy import ndimage
 
 
 def square(width, dtype=np.uint8):
@@ -290,3 +291,23 @@ def star(a, dtype=np.uint8):
     selem = selem_square + selem_rotated
     selem[selem > 0] = 1
     return selem.astype(dtype)
+
+    
+def _default_selem(ndim):
+    """
+    Generates a cross-shaped structuring element (connectivity=1). This is the
+    default structuring element (selem) if no selem was specified.
+
+    Parameters
+    ----------
+    ndim : int
+        Number of dimensions of the image.
+
+    Returns
+    -------
+    selem : ndarray
+        The structuring element where elements of the neighborhood
+        are 1 and 0 otherwise.
+
+    """
+    return ndimage.morphology.generate_binary_structure(ndim, 1)
\ No newline at end of file
diff --git a/skimage/morphology/tests/test_binary.py b/skimage/morphology/tests/test_binary.py
index deab3d82..e6d80321 100644
--- a/skimage/morphology/tests/test_binary.py
+++ b/skimage/morphology/tests/test_binary.py
@@ -64,5 +64,30 @@ def test_out_argument():
         testing.assert_(np.any(out != out_saved))
         testing.assert_array_equal(out, func(img, strel))
 
+def test_default_selem():
+
+    functions = [binary.binary_erosion, binary.binary_dilation,
+                 binary.binary_opening, binary.binary_closing]
+                 
+    strel = selem.diamond(radius=1)
+    image = np.array([[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                      [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 0, 0, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 0, 0, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 0, 0, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                      [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]], np.uint8)
+                      
+    for function in functions:
+        im_expected = function(image, strel)
+        im_test = function(image)
+        yield testing.assert_array_equal, im_expected, im_test
+    
 if __name__ == '__main__':
     testing.run_module_suite()
diff --git a/skimage/morphology/tests/test_grey.py b/skimage/morphology/tests/test_grey.py
index f0099ee5..d298b1eb 100644
--- a/skimage/morphology/tests/test_grey.py
+++ b/skimage/morphology/tests/test_grey.py
@@ -119,7 +119,33 @@ class TestEccentricStructuringElements():
             tophat = grey.black_tophat(self.white_pixel, s)
             assert np.all(tophat == 0)
 
+def test_default_selem():
 
+    functions = [grey.erosion, grey.dilation,
+                 grey.opening, grey.closing,
+                 grey.white_tophat, grey.black_tophat]
+                 
+    strel = selem.diamond(radius=1)
+    image = np.array([[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                      [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 0, 0, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 0, 0, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 0, 0, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
+                      [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                      [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]], np.uint8)
+                      
+    for function in functions:
+        im_expected = function(image, strel)
+        im_test = function(image)
+        yield testing.assert_array_equal, im_expected, im_test
+            
+            
 class TestDTypes():
 
     def setUp(self):

From 54aff88bd019b0ed077fe2bf0b4b9bbdf545df1e Mon Sep 17 00:00:00 2001
From: Nelson Brown <nelson.brown@gmail.com>
Date: Fri, 11 Jul 2014 14:10:18 -0700
Subject: [PATCH 2/6] Add docstring for default structuring element

---
 skimage/morphology/binary.py | 18 +++++++++++-------
 skimage/morphology/grey.py   | 32 +++++++++++++++++++-------------
 2 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/skimage/morphology/binary.py b/skimage/morphology/binary.py
index 636717af..d5e0d92b 100644
--- a/skimage/morphology/binary.py
+++ b/skimage/morphology/binary.py
@@ -18,8 +18,9 @@ def binary_erosion(image, selem=None, out=None):
     ----------
     image : ndarray
         Binary input image.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
+        If None, use cross-shaped structuring element (connectivity=1).
     out : ndarray of bool
         The array to store the result of the morphology. If None is
         passed, a new array will be allocated.
@@ -66,9 +67,10 @@ def binary_dilation(image, selem=None, out=None):
 
     image : ndarray
         Binary input image.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray of bool
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarray of bool, optional
         The array to store the result of the morphology. If None, is
         passed, a new array will be allocated.
 
@@ -113,9 +115,10 @@ def binary_opening(image, selem=None, out=None):
     ----------
     image : ndarray
         Binary input image.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray of bool
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarray of bool, optional
         The array to store the result of the morphology. If None
         is passed, a new array will be allocated.
 
@@ -145,9 +148,10 @@ def binary_closing(image, selem=None, out=None):
     ----------
     image : ndarray
         Binary input image.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray of bool
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarray of bool, optional
         The array to store the result of the morphology. If None,
         is passed, a new array will be allocated.
 
diff --git a/skimage/morphology/grey.py b/skimage/morphology/grey.py
index 7fb1c8c9..e50e1460 100644
--- a/skimage/morphology/grey.py
+++ b/skimage/morphology/grey.py
@@ -22,12 +22,13 @@ def erosion(image, selem=None, out=None, shift_x=False, shift_y=False):
     ----------
     image : ndarray
         Image array.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarrays
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarrays, optional
         The array to store the result of the morphology. If None is
         passed, a new array will be allocated.
-    shift_x, shift_y : bool
+    shift_x, shift_y : bool, optional
         shift structuring element about center point. This only affects
         eccentric structuring elements (i.e. selem with even numbered sides).
 
@@ -79,12 +80,13 @@ def dilation(image, selem=None, out=None, shift_x=False, shift_y=False):
 
     image : ndarray
         Image array.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarray, optional
         The array to store the result of the morphology. If None, is
         passed, a new array will be allocated.
-    shift_x, shift_y : bool
+    shift_x, shift_y : bool, optional
         shift structuring element about center point. This only affects
         eccentric structuring elements (i.e. selem with even numbered sides).
 
@@ -136,9 +138,10 @@ def opening(image, selem=None, out=None):
     ----------
     image : ndarray
         Image array.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarray, optional
         The array to store the result of the morphology. If None
         is passed, a new array will be allocated.
 
@@ -191,9 +194,10 @@ def closing(image, selem=None, out=None):
     ----------
     image : ndarray
         Image array.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarray, optional
         The array to store the result of the morphology. If None,
         is passed, a new array will be allocated.
 
@@ -245,9 +249,10 @@ def white_tophat(image, selem=None, out=None):
     ----------
     image : ndarray
         Image array.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
-    out : ndarray
+        If None, use cross-shaped structuring element (connectivity=1).
+    out : ndarray, optional
         The array to store the result of the morphology. If None
         is passed, a new array will be allocated.
 
@@ -299,8 +304,9 @@ def black_tophat(image, selem=None, out=None):
     ----------
     image : ndarray
         Image array.
-    selem : ndarray
+    selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
+        If None, use cross-shaped structuring element (connectivity=1).
     out : ndarray
         The array to store the result of the morphology. If None
         is passed, a new array will be allocated.

From 1ef556b7104d1c57a8a47309d878553966ad0f1a Mon Sep 17 00:00:00 2001
From: Nelson Brown <nelson.brown@gmail.com>
Date: Fri, 11 Jul 2014 14:51:57 -0700
Subject: [PATCH 3/6] Remove unnecessary whitespace

---
 skimage/morphology/binary.py            |  8 ++++----
 skimage/morphology/grey.py              | 16 ++++++++--------
 skimage/morphology/selem.py             |  2 +-
 skimage/morphology/tests/test_binary.py |  5 +----
 skimage/morphology/tests/test_grey.py   |  6 +-----
 5 files changed, 15 insertions(+), 22 deletions(-)

diff --git a/skimage/morphology/binary.py b/skimage/morphology/binary.py
index d5e0d92b..5b019051 100644
--- a/skimage/morphology/binary.py
+++ b/skimage/morphology/binary.py
@@ -31,11 +31,11 @@ def binary_erosion(image, selem=None, out=None):
         The result of the morphological erosion with values in ``[0, 1]``.
 
     """
-    
+
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-        
+
     selem = (selem != 0)
     selem_sum = np.sum(selem)
 
@@ -80,11 +80,11 @@ def binary_dilation(image, selem=None, out=None):
         The result of the morphological dilation with values in ``[0, 1]``.
 
     """
-    
+
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-        
+
     selem = (selem != 0)
 
     if np.sum(selem) <= 255:
diff --git a/skimage/morphology/grey.py b/skimage/morphology/grey.py
index e50e1460..2b4a01a8 100644
--- a/skimage/morphology/grey.py
+++ b/skimage/morphology/grey.py
@@ -59,7 +59,7 @@ def erosion(image, selem=None, out=None, shift_x=False, shift_y=False):
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-        
+
     if image is out:
         raise NotImplementedError("In-place erosion not supported!")
     image = img_as_ubyte(image)
@@ -117,7 +117,7 @@ def dilation(image, selem=None, out=None, shift_x=False, shift_y=False):
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-    
+
     if image is out:
         raise NotImplementedError("In-place dilation not supported!")
     image = img_as_ubyte(image)
@@ -168,11 +168,11 @@ def opening(image, selem=None, out=None):
            [0, 0, 0, 0, 0]], dtype=uint8)
 
     """
-    
+
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-        
+
     h, w = selem.shape
     shift_x = True if (w % 2) == 0 else False
     shift_y = True if (h % 2) == 0 else False
@@ -228,7 +228,7 @@ def closing(image, selem=None, out=None):
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-    
+
     h, w = selem.shape
     shift_x = True if (w % 2) == 0 else False
     shift_y = True if (h % 2) == 0 else False
@@ -279,11 +279,11 @@ def white_tophat(image, selem=None, out=None):
            [0, 0, 0, 0, 0]], dtype=uint8)
 
     """
-   
+
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-        
+
     if image is out:
         raise NotImplementedError("Cannot perform white top hat in place.")
 
@@ -338,7 +338,7 @@ def black_tophat(image, selem=None, out=None):
     # Default structure element
     if selem is None:
         selem = _default_selem(image.ndim)
-        
+
     if image is out:
         raise NotImplementedError("Cannot perform white top hat in place.")
 
diff --git a/skimage/morphology/selem.py b/skimage/morphology/selem.py
index 24adfce6..4147d93b 100644
--- a/skimage/morphology/selem.py
+++ b/skimage/morphology/selem.py
@@ -292,7 +292,7 @@ def star(a, dtype=np.uint8):
     selem[selem > 0] = 1
     return selem.astype(dtype)
 
-    
+
 def _default_selem(ndim):
     """
     Generates a cross-shaped structuring element (connectivity=1). This is the
diff --git a/skimage/morphology/tests/test_binary.py b/skimage/morphology/tests/test_binary.py
index e6d80321..6ac5e8d8 100644
--- a/skimage/morphology/tests/test_binary.py
+++ b/skimage/morphology/tests/test_binary.py
@@ -65,10 +65,8 @@ def test_out_argument():
         testing.assert_array_equal(out, func(img, strel))
 
 def test_default_selem():
-
     functions = [binary.binary_erosion, binary.binary_dilation,
                  binary.binary_opening, binary.binary_closing]
-                 
     strel = selem.diamond(radius=1)
     image = np.array([[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
                       [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
@@ -83,11 +81,10 @@ def test_default_selem():
                       [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
                       [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
                       [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]], np.uint8)
-                      
     for function in functions:
         im_expected = function(image, strel)
         im_test = function(image)
         yield testing.assert_array_equal, im_expected, im_test
-    
+
 if __name__ == '__main__':
     testing.run_module_suite()
diff --git a/skimage/morphology/tests/test_grey.py b/skimage/morphology/tests/test_grey.py
index d298b1eb..359a2832 100644
--- a/skimage/morphology/tests/test_grey.py
+++ b/skimage/morphology/tests/test_grey.py
@@ -120,11 +120,9 @@ class TestEccentricStructuringElements():
             assert np.all(tophat == 0)
 
 def test_default_selem():
-
     functions = [grey.erosion, grey.dilation,
                  grey.opening, grey.closing,
                  grey.white_tophat, grey.black_tophat]
-                 
     strel = selem.diamond(radius=1)
     image = np.array([[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
                       [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
@@ -139,13 +137,11 @@ def test_default_selem():
                       [0, 0, 1, 1, 1, 1, 1, 1, 0, 0],
                       [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
                       [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]], np.uint8)
-                      
     for function in functions:
         im_expected = function(image, strel)
         im_test = function(image)
         yield testing.assert_array_equal, im_expected, im_test
-            
-            
+
 class TestDTypes():
 
     def setUp(self):

From 9cd9a1372ae98a8787221e99b0339a1876e09255 Mon Sep 17 00:00:00 2001
From: Nelson Brown <nelson.brown@gmail.com>
Date: Fri, 11 Jul 2014 15:19:33 -0700
Subject: [PATCH 4/6] Address reviewer comments

Add newline at EOF of selem.py
Add "optional" to grey.py and binary.py
---
 skimage/morphology/binary.py | 2 +-
 skimage/morphology/grey.py   | 2 +-
 skimage/morphology/selem.py  | 3 ++-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/skimage/morphology/binary.py b/skimage/morphology/binary.py
index 5b019051..4612a35d 100644
--- a/skimage/morphology/binary.py
+++ b/skimage/morphology/binary.py
@@ -21,7 +21,7 @@ def binary_erosion(image, selem=None, out=None):
     selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
         If None, use cross-shaped structuring element (connectivity=1).
-    out : ndarray of bool
+    out : ndarray of bool, optional
         The array to store the result of the morphology. If None is
         passed, a new array will be allocated.
 
diff --git a/skimage/morphology/grey.py b/skimage/morphology/grey.py
index 2b4a01a8..565ec9a6 100644
--- a/skimage/morphology/grey.py
+++ b/skimage/morphology/grey.py
@@ -307,7 +307,7 @@ def black_tophat(image, selem=None, out=None):
     selem : ndarray, optional
         The neighborhood expressed as a 2-D array of 1's and 0's.
         If None, use cross-shaped structuring element (connectivity=1).
-    out : ndarray
+    out : ndarray, optional
         The array to store the result of the morphology. If None
         is passed, a new array will be allocated.
 
diff --git a/skimage/morphology/selem.py b/skimage/morphology/selem.py
index 4147d93b..36ce4fe9 100644
--- a/skimage/morphology/selem.py
+++ b/skimage/morphology/selem.py
@@ -310,4 +310,5 @@ def _default_selem(ndim):
         are 1 and 0 otherwise.
 
     """
-    return ndimage.morphology.generate_binary_structure(ndim, 1)
\ No newline at end of file
+    return ndimage.morphology.generate_binary_structure(ndim, 1)
+    
\ No newline at end of file

From c2bbca6113e78adf7e263aaa9156e109006124ef Mon Sep 17 00:00:00 2001
From: Nelson Brown <nelson.brown@gmail.com>
Date: Fri, 11 Jul 2014 23:32:36 -0700
Subject: [PATCH 5/6] Add a newline at EOF

---
 skimage/morphology/selem.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/skimage/morphology/selem.py b/skimage/morphology/selem.py
index 36ce4fe9..b7b65d72 100644
--- a/skimage/morphology/selem.py
+++ b/skimage/morphology/selem.py
@@ -311,4 +311,4 @@ def _default_selem(ndim):
 
     """
     return ndimage.morphology.generate_binary_structure(ndim, 1)
-    
\ No newline at end of file
+

From 3518e65ab456ebba870a22632cad201a2dba8484 Mon Sep 17 00:00:00 2001
From: Nelson Brown <nelson.brown@gmail.com>
Date: Fri, 11 Jul 2014 23:39:07 -0700
Subject: [PATCH 6/6] Add newline at EOF of selem.py

---
 skimage/morphology/selem.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/skimage/morphology/selem.py b/skimage/morphology/selem.py
index b7b65d72..1822c8b3 100644
--- a/skimage/morphology/selem.py
+++ b/skimage/morphology/selem.py
@@ -312,3 +312,9 @@ def _default_selem(ndim):
     """
     return ndimage.morphology.generate_binary_structure(ndim, 1)
 
+
+
+
+
+
+