Toolbox ia870 | List of Figures | Fig. 2.1 | Fig. 2.3

Figure 2.2 - Opening top-hat


In Fig. 2.1, the opening top-hat consists of input-image corners that protrude into the background, and it can be employed for recognition purposes. Figure 2.2 shows another example of the opening top-hat to detect the teeth of a gear. Use of a disk is common because its shape-effect is rotationally invariant; however, there are many instances when it is beneficial to employ other kinds of structuring elements.

Demo Script

 1 import numpy as np
 2 import ia870 as MT
 3 import ia636 as ia
 4 from handson.lib import draw_se_axis
 6 F = adreadgray('gear.tif')
 7 adshow(MT.ianeg(F), '(a) Structuring element')
 9 B = MT.iasedisk(10)
10 adshow(MT.ianeg(draw_se_axis(MT.iaseshow(B))), '(b) input image')
12 E = MT.iaopen(F,B)
13 adshow(MT.ianeg(E), '(c) opening')
15 O = MT.iaopenth(F,B)
16 adshow(MT.ianeg(O), '(d) opening top-hat')

(a) Structuring element

(b) input image

(c) opening

(d) opening top-hat