Fix region props deprecation problem with label function

skimage/measure/_label.py

@@ -1,7 +1,7 @@
 from ._ccomp import label as _label
 
 def label(input, neighbors=None, background=None, return_num=False,
-        connectivity=None):
+          connectivity=None):
     return _label(input, neighbors, background, return_num, connectivity)
 
 label.__doc__ = _label.__doc__

skimage/measure/_regionprops.py

@@ -157,7 +157,7 @@ class _RegionProperties(object):
     @property
     def euler_number(self):
         euler_array = self.filled_image != self.image
-        _, num = label(euler_array, neighbors=8, return_num=True)
+        _, num = label(euler_array, neighbors=8, return_num=True, background=-1)
         return -num + 1
 
     @property
@@ -473,7 +473,7 @@ def regionprops(label_image, intensity_image=None, cache=True):
     Examples
     --------
     >>> from skimage import data, util
-    >>> from skimage.morphology import label
+    >>> from skimage.measure import label
     >>> img = util.img_as_ubyte(data.coins()) > 110
     >>> label_img = label(img, connectivity=img.ndim)
     >>> props = regionprops(label_img)

skimage/measure/tests/test_regionprops.py

@@ -128,14 +128,12 @@ def test_equiv_diameter():
 
 
 def test_euler_number():
-    with expected_warnings(['`background`|CObject type']):
-        en = regionprops(SAMPLE)[0].euler_number
+    en = regionprops(SAMPLE)[0].euler_number
     assert en == 0
 
     SAMPLE_mod = SAMPLE.copy()
     SAMPLE_mod[7, -3] = 0
-    with expected_warnings(['`background`|CObject type']):
-        en = regionprops(SAMPLE_mod)[0].euler_number
+    en = regionprops(SAMPLE_mod)[0].euler_number
     assert en == -1
 
 
@@ -374,9 +372,8 @@ def test_equals():
     r2 = regions[0]
     r3 = regions[1]
 
-    with expected_warnings(['`background`|CObject type']):
-        assert_equal(r1 == r2, True, "Same regionprops are not equal")
-        assert_equal(r1 != r3, True, "Different regionprops are equal")
+    assert_equal(r1 == r2, True, "Same regionprops are not equal")
+    assert_equal(r1 != r3, True, "Different regionprops are equal")
 
 
 if __name__ == "__main__":