Add remaining greyscale morphology operations to cupyx.scipy.ndimage

cupyx/scipy/ndimage/__init__.py

@@ -43,3 +43,7 @@
 from cupyx.scipy.ndimage.morphology import grey_dilation  # NOQA
 from cupyx.scipy.ndimage.morphology import grey_closing  # NOQA
 from cupyx.scipy.ndimage.morphology import grey_opening  # NOQA
+from cupyx.scipy.ndimage.morphology import morphological_gradient  # NOQA
+from cupyx.scipy.ndimage.morphology import morphological_laplace  # NOQA
+from cupyx.scipy.ndimage.morphology import white_tophat  # NOQA
+from cupyx.scipy.ndimage.morphology import black_tophat  # NOQA

cupyx/scipy/ndimage/morphology.py

@@ -141,7 +141,7 @@ def grey_closing(input, size=None, footprint=None, structure=None,
     .. seealso:: :func:`scipy.ndimage.grey_closing`
     """
     if (size is not None) and (footprint is not None):
-        warnings.warn("ignoring size because footprint is set", UserWarning,
+        warnings.warn('ignoring size because footprint is set', UserWarning,
                       stacklevel=2)
     tmp = grey_dilation(input, size, footprint, structure, None, mode, cval,
                         origin)
@@ -182,9 +182,246 @@ def grey_opening(input, size=None, footprint=None, structure=None,
     .. seealso:: :func:`scipy.ndimage.grey_opening`
     """
     if (size is not None) and (footprint is not None):
-        warnings.warn("ignoring size because footprint is set", UserWarning,
+        warnings.warn('ignoring size because footprint is set', UserWarning,
                       stacklevel=2)
     tmp = grey_erosion(input, size, footprint, structure, None, mode, cval,
                        origin)
     return grey_dilation(tmp, size, footprint, structure, output, mode, cval,
                          origin)
+
+
+def morphological_gradient(
+    input,
+    size=None,
+    footprint=None,
+    structure=None,
+    output=None,
+    mode='reflect',
+    cval=0.0,
+    origin=0,
+):
+    """
+    Multidimensional morphological gradient.
+
+    The morphological gradient is calculated as the difference between a
+    dilation and an erosion of the input with a given structuring element.
+
+    Args:
+        input (cupy.ndarray): The input array.
+        size (tuple of ints): Shape of a flat and full structuring element used
+            for the morphological gradient. Optional if ``footprint`` or
+            ``structure`` is provided.
+        footprint (array of ints): Positions of non-infinite elements of a flat
+            structuring element used for morphological gradient. Non-zero
+            values give the set of neighbors of the center over which opening
+            is chosen.
+        structure (array of ints): Structuring element used for the
+            morphological gradient. ``structure`` may be a non-flat
+            structuring element.
+        output (cupy.ndarray, dtype or None): The array in which to place the
+            output.
+        mode (str): The array borders are handled according to the given mode
+            (``'reflect'``, ``'constant'``, ``'nearest'``, ``'mirror'``,
+            ``'wrap'``). Default is ``'reflect'``.
+        cval (scalar): Value to fill past edges of input if mode is
+            ``constant``. Default is ``0.0``.
+        origin (scalar or tuple of scalar): The origin parameter controls the
+            placement of the filter, relative to the center of the current
+            element of the input. Default of 0 is equivalent to
+            ``(0,)*input.ndim``.
+
+    Returns:
+        cupy.ndarray: The morphological gradient of the input.
+
+    .. seealso:: :func:`scipy.ndimage.morphological_gradient`
+    """
+    tmp = grey_dilation(
+        input, size, footprint, structure, None, mode, cval, origin
+    )
+    if isinstance(output, cupy.ndarray):
+        grey_erosion(
+            input, size, footprint, structure, output, mode, cval, origin
+        )
+        return cupy.subtract(tmp, output, output)
+    else:
+        return tmp - grey_erosion(
+            input, size, footprint, structure, None, mode, cval, origin
+        )
+
+
+def morphological_laplace(
+    input,
+    size=None,
+    footprint=None,
+    structure=None,
+    output=None,
+    mode='reflect',
+    cval=0.0,
+    origin=0,
+):
+    """
+    Multidimensional morphological laplace.
+
+    Args:
+        input (cupy.ndarray): The input array.
+        size (tuple of ints): Shape of a flat and full structuring element used
+            for the morphological laplace. Optional if ``footprint`` or
+            ``structure`` is provided.
+        footprint (array of ints): Positions of non-infinite elements of a flat
+            structuring element used for morphological laplace. Non-zero
+            values give the set of neighbors of the center over which opening
+            is chosen.
+        structure (array of ints): Structuring element used for the
+            morphological laplace. ``structure`` may be a non-flat
+            structuring element.
+        output (cupy.ndarray, dtype or None): The array in which to place the
+            output.
+        mode (str): The array borders are handled according to the given mode
+            (``'reflect'``, ``'constant'``, ``'nearest'``, ``'mirror'``,
+            ``'wrap'``). Default is ``'reflect'``.
+        cval (scalar): Value to fill past edges of input if mode is
+            ``constant``. Default is ``0.0``.
+        origin (scalar or tuple of scalar): The origin parameter controls the
+            placement of the filter, relative to the center of the current
+            element of the input. Default of 0 is equivalent to
+            ``(0,)*input.ndim``.
+
+    Returns:
+        cupy.ndarray: The morphological laplace of the input.
+
+    .. seealso:: :func:`scipy.ndimage.morphological_laplace`
+    """
+    tmp1 = grey_dilation(
+        input, size, footprint, structure, None, mode, cval, origin
+    )
+    if isinstance(output, cupy.ndarray):
+        grey_erosion(
+            input, size, footprint, structure, output, mode, cval, origin
+        )
+        cupy.add(tmp1, output, output)
+        cupy.subtract(output, input, output)
+        return cupy.subtract(output, input, output)
+    else:
+        tmp2 = grey_erosion(
+            input, size, footprint, structure, None, mode, cval, origin
+        )
+        cupy.add(tmp1, tmp2, tmp2)
+        cupy.subtract(tmp2, input, tmp2)
+        cupy.subtract(tmp2, input, tmp2)
+        return tmp2
+
+
+def white_tophat(
+    input,
+    size=None,
+    footprint=None,
+    structure=None,
+    output=None,
+    mode='reflect',
+    cval=0.0,
+    origin=0,
+):
+    """
+    Multidimensional white tophat filter.
+
+    Args:
+        input (cupy.ndarray): The input array.
+        size (tuple of ints): Shape of a flat and full structuring element used
+            for the white tophat. Optional if ``footprint`` or ``structure`` is
+            provided.
+        footprint (array of ints): Positions of non-infinite elements of a flat
+            structuring element used for the white tophat. Non-zero values
+            give the set of neighbors of the center over which opening is
+            chosen.
+        structure (array of ints): Structuring element used for the white
+            tophat. ``structure`` may be a non-flat structuring element.
+        output (cupy.ndarray, dtype or None): The array in which to place the
+            output.
+        mode (str): The array borders are handled according to the given mode
+            (``'reflect'``, ``'constant'``, ``'nearest'``, ``'mirror'``,
+            ``'wrap'``). Default is ``'reflect'``.
+        cval (scalar): Value to fill past edges of input if mode is
+            ``constant``. Default is ``0.0``.
+        origin (scalar or tuple of scalar): The origin parameter controls the
+            placement of the filter, relative to the center of the current
+            element of the input. Default of 0 is equivalent to
+            ``(0,)*input.ndim``.
+
+    Returns:
+        cupy.ndarray: Result of the filter of ``input`` with ``structure``.
+
+    .. seealso:: :func:`scipy.ndimage.white_tophat`
+    """
+    if (size is not None) and (footprint is not None):
+        warnings.warn(
+            'ignoring size because footprint is set', UserWarning, stacklevel=2
+        )
+    tmp = grey_erosion(
+        input, size, footprint, structure, None, mode, cval, origin
+    )
+    tmp = grey_dilation(
+        tmp, size, footprint, structure, output, mode, cval, origin
+    )
+    if input.dtype == numpy.bool_ and tmp.dtype == numpy.bool_:
+        cupy.bitwise_xor(input, tmp, out=tmp)
+    else:
+        cupy.subtract(input, tmp, out=tmp)
+    return tmp
+
+
+def black_tophat(
+    input,
+    size=None,
+    footprint=None,
+    structure=None,
+    output=None,
+    mode='reflect',
+    cval=0.0,
+    origin=0,
+):
+    """
+    Multidimensional black tophat filter.
+
+    Args:
+        input (cupy.ndarray): The input array.
+        size (tuple of ints): Shape of a flat and full structuring element used
+            for the black tophat. Optional if ``footprint`` or ``structure`` is
+            provided.
+        footprint (array of ints): Positions of non-infinite elements of a flat
+            structuring element used for the black tophat. Non-zero values
+            give the set of neighbors of the center over which opening is
+            chosen.
+        structure (array of ints): Structuring element used for the black
+            tophat. ``structure`` may be a non-flat structuring element.
+        output (cupy.ndarray, dtype or None): The array in which to place the
+            output.
+        mode (str): The array borders are handled according to the given mode
+            (``'reflect'``, ``'constant'``, ``'nearest'``, ``'mirror'``,
+            ``'wrap'``). Default is ``'reflect'``.
+        cval (scalar): Value to fill past edges of input if mode is
+            ``constant``. Default is ``0.0``.
+        origin (scalar or tuple of scalar): The origin parameter controls the
+            placement of the filter, relative to the center of the current
+            element of the input. Default of 0 is equivalent to
+            ``(0,)*input.ndim``.
+
+    Returns:
+        cupy.ndarry : Result of the filter of ``input`` with ``structure``.
+
+    .. seealso:: :func:`scipy.ndimage.black_tophat`
+    """
+    if (size is not None) and (footprint is not None):
+        warnings.warn(
+            'ignoring size because footprint is set', UserWarning, stacklevel=2
+        )
+    tmp = grey_dilation(
+        input, size, footprint, structure, None, mode, cval, origin
+    )
+    tmp = grey_erosion(
+        tmp, size, footprint, structure, output, mode, cval, origin
+    )
+    if input.dtype == numpy.bool_ and tmp.dtype == numpy.bool_:
+        cupy.bitwise_xor(tmp, input, out=tmp)
+    else:
+        cupy.subtract(tmp, input, out=tmp)
+    return tmp