678326.fig.002a
(a)
678326.fig.002b
(b)
678326.fig.002c
(c)
678326.fig.002d
(d)
678326.fig.002e
(e)
Figure 2: Map (a) with its erosion (b), dilation (c), opening (d), and closing (e) with a disk of radius 3 pixels. Method of Angulo in RGB color space choosing black as the reference color.