Mention which parameters to label are optional. Simplify label deprecation.

skimage/measure/_ccomp.pyx

@@ -101,13 +101,13 @@ def label(input, DTYPE_t neighbors=8, background=None, return_num=False):
     ----------
     input : ndarray of dtype int
         Image to label.
-    neighbors : {4, 8}, int
+    neighbors : {4, 8}, int, optional
         Whether to use 4- or 8-connectivity.
-    background : int
+    background : int, optional
         Consider all pixels with this value as background pixels, and label
         them as -1. (Note: background pixels will be labeled as 0 starting with
         version 0.12).
-    return_num : bool
+    return_num : bool, optional
         Whether to return the number of assigned labels.
 
     Returns

skimage/morphology/_label.py

@@ -3,69 +3,4 @@ __all__ = ['label']
 from ..measure._ccomp import label as _label
 from skimage._shared.utils import deprecated
 
-@deprecated('skimage.measure.label')
-def label(input, neighbors=8, background=None, return_num=False):
-    """Label connected regions of an integer array.
-
-    Two pixels are connected when they are neighbors and have the same value.
-    They can be neighbors either in a 4- or 8-connected sense::
-
-      4-connectivity      8-connectivity
-
-           [ ]           [ ]  [ ]  [ ]
-            |               \  |  /
-      [ ]--[ ]--[ ]      [ ]--[ ]--[ ]
-            |               /  |  \\
-           [ ]           [ ]  [ ]  [ ]
-
-    Parameters
-    ----------
-    input : ndarray of dtype int
-        Image to label.
-    neighbors : {4, 8}, int
-        Whether to use 4- or 8-connectivity.
-    background : int
-        Consider all pixels with this value as background pixels, and label
-        them as -1. (Note: background pixels will be labeled as 0 starting with
-        version 0.12).
-    return_num : bool
-        Whether to return the number of assigned labels.
-
-    Returns
-    -------
-    labels : ndarray of dtype int
-        Labeled array, where all connected regions are assigned the
-        same integer value.
-    num : int, optional
-        Number of labels, which equals the maximum label index and is only
-        returned if return_num is `True`.
-
-    Examples
-    --------
-    >>> x = np.eye(3).astype(int)
-    >>> print(x)
-    [[1 0 0]
-     [0 1 0]
-     [0 0 1]]
-
-    >>> print(m.label(x, neighbors=4))
-    [[0 1 1]
-     [2 3 1]
-     [2 2 4]]
-
-    >>> print(m.label(x, neighbors=8))
-    [[0 1 1]
-     [1 0 1]
-     [1 1 0]]
-
-    >>> x = np.array([[1, 0, 0],
-    ...               [1, 1, 5],
-    ...               [0, 0, 0]])
-
-    >>> print(m.label(x, background=0))
-    [[ 0 -1 -1]
-     [ 0  0  1]
-     [-1 -1 -1]]
-
-    """
-    return _label(input, neighbors, background, return_num)
+label = deprecated('skimage.measure.label')(_label)