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grey_opening(input, size=None, footprint=None, structure=None, output=None, mode='reflect', cval=0.0, origin=0)

A grayscale opening consists in the succession of a grayscale erosion, and a grayscale dilation.

Notes

The action of a grayscale opening with a flat structuring element amounts to smoothen high local maxima, whereas binary opening erases small objects.

Parameters

input : array_like: Array over which the grayscale opening is to be computed.
size : tuple of ints: Shape of a flat and full structuring element used for the grayscale opening. Optional if footprint or structure is provided.
footprint : array of ints, optional: Positions of non-infinite elements of a flat structuring element used for the grayscale opening.
structure : array of ints, optional: Structuring element used for the grayscale opening. structure may be a non-flat structuring element.
output : array, optional: An array used for storing the output of the opening may be provided.
mode : {'reflect', 'constant', 'nearest', 'mirror', 'wrap'}, optional: The mode parameter determines how the array borders are handled, where cval is the value when mode is equal to 'constant'. Default is 'reflect'
cval : scalar, optional: Value to fill past edges of input if mode is 'constant'. Default is 0.0.
origin : scalar, optional: The origin parameter controls the placement of the filter. Default 0

Returns

grey_opening : ndarray: Result of the grayscale opening of input with structure.

Multidimensional grayscale opening.

Examples

from scipy import ndimage
import numpy as np
a = np.arange(36).reshape((6,6))
a[3, 3] = 50
a

ndimage.grey_opening(a, size=(3,3))

# Note that the local maximum a[3,3] has disappeared

See :

Back References

The following pages refer to to this document either explicitly or contain code examples using this.

scipy.ndimage._morphology:binary_opening scipy.ndimage._morphology:black_tophat scipy.ndimage._morphology:grey_erosion scipy.ndimage._morphology:grey_closing scipy.ndimage._morphology:grey_dilation

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