A Computational Introduction to Digital Image Processing, 2nd Edition

Mathematical Morphology 301

MATLAB/Octave

>> str2 = strel(’arbitrary’,ones(3,3),[9 8 7;6 5 4;3 2 1])

str2 =

Nonflat STREL object containing 9 neighbors.

Neighborhood:

1 1 1

1 1 1

1 1 1

Height:

9 8 7

6 5 4

3 2 1

>> imdilate(A,str2)

ans =

39 39 49 59 58

39 39 59 69 68

49 59 59 69 68

59 69 69 79 78

56 66 66 76 75

In Python the same result is obtained with gray

_

dilation:

Python

In : struct2 = np.array([[9,8,7],[6,5,4],[3,2,1]])

In : print ndi.gray

_

dilation(A,footprint=mo.square(3),\

...: structure=struct,mode=’constant’)

[[39 39 49 59 59]

[39 39 59 69 69]

[49 59 59 69 69]

[59 69 69 79 79]

[59 69 69 79 79]]

Now we can experiment with an image. We would expect that dilation