158 lines
5.2 KiB
Python
158 lines
5.2 KiB
Python
"""
|
|
Binary morphological operations
|
|
"""
|
|
import numpy as np
|
|
from scipy import ndimage as ndi
|
|
|
|
from .._shared.utils import deprecate_kwarg
|
|
from .misc import default_footprint
|
|
|
|
|
|
# The default_footprint decorator provides a diamond footprint as
|
|
# default with the same dimension as the input image and size 3 along each
|
|
# axis.
|
|
@default_footprint
|
|
@deprecate_kwarg(kwarg_mapping={'selem': 'footprint'}, removed_version="1.0",
|
|
deprecated_version="0.19")
|
|
def binary_erosion(image, footprint=None, out=None):
|
|
"""Return fast binary morphological erosion of an image.
|
|
|
|
This function returns the same result as grayscale erosion but performs
|
|
faster for binary images.
|
|
|
|
Morphological erosion sets a pixel at ``(i,j)`` to the minimum over all
|
|
pixels in the neighborhood centered at ``(i,j)``. Erosion shrinks bright
|
|
regions and enlarges dark regions.
|
|
|
|
Parameters
|
|
----------
|
|
image : ndarray
|
|
Binary input image.
|
|
footprint : ndarray, optional
|
|
The neighborhood expressed as a 2-D array of 1's and 0's.
|
|
If None, use a cross-shaped footprint (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.
|
|
|
|
Returns
|
|
-------
|
|
eroded : ndarray of bool or uint
|
|
The result of the morphological erosion taking values in
|
|
``[False, True]``.
|
|
|
|
"""
|
|
if out is None:
|
|
out = np.empty(image.shape, dtype=bool)
|
|
ndi.binary_erosion(image, structure=footprint, output=out,
|
|
border_value=True)
|
|
return out
|
|
|
|
|
|
@default_footprint
|
|
@deprecate_kwarg(kwarg_mapping={'selem': 'footprint'}, removed_version="1.0",
|
|
deprecated_version="0.19")
|
|
def binary_dilation(image, footprint=None, out=None):
|
|
"""Return fast binary morphological dilation of an image.
|
|
|
|
This function returns the same result as grayscale dilation but performs
|
|
faster for binary images.
|
|
|
|
Morphological dilation sets a pixel at ``(i,j)`` to the maximum over all
|
|
pixels in the neighborhood centered at ``(i,j)``. Dilation enlarges bright
|
|
regions and shrinks dark regions.
|
|
|
|
Parameters
|
|
----------
|
|
image : ndarray
|
|
Binary input image.
|
|
footprint : ndarray, optional
|
|
The neighborhood expressed as a 2-D array of 1's and 0's.
|
|
If None, use a cross-shaped footprint (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.
|
|
|
|
Returns
|
|
-------
|
|
dilated : ndarray of bool or uint
|
|
The result of the morphological dilation with values in
|
|
``[False, True]``.
|
|
"""
|
|
if out is None:
|
|
out = np.empty(image.shape, dtype=bool)
|
|
ndi.binary_dilation(image, structure=footprint, output=out)
|
|
return out
|
|
|
|
|
|
@default_footprint
|
|
@deprecate_kwarg(kwarg_mapping={'selem': 'footprint'}, removed_version="1.0",
|
|
deprecated_version="0.19")
|
|
def binary_opening(image, footprint=None, out=None):
|
|
"""Return fast binary morphological opening of an image.
|
|
|
|
This function returns the same result as grayscale opening but performs
|
|
faster for binary images.
|
|
|
|
The morphological opening on an image is defined as an erosion followed by
|
|
a dilation. Opening can remove small bright spots (i.e. "salt") and connect
|
|
small dark cracks. This tends to "open" up (dark) gaps between (bright)
|
|
features.
|
|
|
|
Parameters
|
|
----------
|
|
image : ndarray
|
|
Binary input image.
|
|
footprint : ndarray, optional
|
|
The neighborhood expressed as a 2-D array of 1's and 0's.
|
|
If None, use a cross-shaped footprint (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.
|
|
|
|
Returns
|
|
-------
|
|
opening : ndarray of bool
|
|
The result of the morphological opening.
|
|
|
|
"""
|
|
eroded = binary_erosion(image, footprint)
|
|
out = binary_dilation(eroded, footprint, out=out)
|
|
return out
|
|
|
|
|
|
@default_footprint
|
|
@deprecate_kwarg(kwarg_mapping={'selem': 'footprint'}, removed_version="1.0",
|
|
deprecated_version="0.19")
|
|
def binary_closing(image, footprint=None, out=None):
|
|
"""Return fast binary morphological closing of an image.
|
|
|
|
This function returns the same result as grayscale closing but performs
|
|
faster for binary images.
|
|
|
|
The morphological closing on an image is defined as a dilation followed by
|
|
an erosion. Closing can remove small dark spots (i.e. "pepper") and connect
|
|
small bright cracks. This tends to "close" up (dark) gaps between (bright)
|
|
features.
|
|
|
|
Parameters
|
|
----------
|
|
image : ndarray
|
|
Binary input image.
|
|
footprint : ndarray, optional
|
|
The neighborhood expressed as a 2-D array of 1's and 0's.
|
|
If None, use a cross-shaped footprint (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.
|
|
|
|
Returns
|
|
-------
|
|
closing : ndarray of bool
|
|
The result of the morphological closing.
|
|
|
|
"""
|
|
dilated = binary_dilation(image, footprint)
|
|
out = binary_erosion(dilated, footprint, out=out)
|
|
return out
|