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mmero
Erode an image by a structuring element.

Synopsis

y = mmero ( f , b = NullStrel )

Input

f Image Gray-scale (uint8 or uint16) or binary image

b Structuring Element

Default: NullStrel (3x3 elementary cross)

Output

y Image

Description

mmero performs the erosion of the image f by the structuring element b. Erosion is a neighbourhood operator that compairs locally b with f, according to an inclusion rule. Since erosion is a fundamental operator to the construction of all other morphological operators, it is also called an elementary operator of Mathematical Morphology. When f is a gray-scale image , b may be a flat or non-flat structuring element.

Examples

Numerical examples
f=mmbinary([
   [1, 1, 1, 0, 0, 1, 1],
   [1, 0, 1, 1, 1, 0, 0],
   [0, 0, 0, 0, 1, 0, 0]])
b=mmbinary([1, 1, 0])
mmero(f,b)
array([[ True,  True,  True, False, False, False,  True],
       [ True, False, False,  True,  True, False, False],
       [False, False, False, False, False, False, False]], dtype=bool)
f=uint8([
   [ 0,   1,  2, 50,  4,  5],
   [ 2,   3,  4,  0,  0,  0],
   [12, 255, 14, 15, 16, 17]])
mmero(f,b)
array([[ 0,  0,  1,  2,  4,  4],
       [ 2,  2,  3,  0,  0,  0],
       [12, 12, 14, 14, 15, 16]], dtype=uint8)
f=mmbinary(mmreadgray('blob.tif'))
bimg=mmbinary(mmreadgray('blob1.tif'))
b=mmimg2se(bimg)
g=mmero(f,b)
mmshow(f)
mmshow(g)
mmshow(g,mmgradm(f))
f g
g,mmgradm(f)
Gray-scale image:
f=mmreadgray('pcb_gray.tif')
b=mmsedisk(3)
mmshow(f)
mmshow(mmero(f,b))
f mmero(f,b)

Equation

Flat structuring element:
Non-flat structuring element:
Where

See also

mmfreedom Control automatic data type conversion.
mmdil Dilate an image by a structuring element.
mmimg2se Create a structuring element from a pair of images.
mmsebox Create a box structuring element.
mmsecross Diamond structuring element and elementary 3x3 cross.
mmcero Erode an image conditionally.
mmdist Distance transform.
mmsesum N-1 iterative Minkowski additions

See also

mmfreedom Control automatic data type conversion.
mmdil Dilate an image by a structuring element.
mmsecross Diamond structuring element and elementary 3x3 cross.
mmcero Erode an image conditionally.
mmdist Distance transform.
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