Digital Geometry in Image Processing

152 Digital Geometry in Image Processing

FIGURE 4.6: Re sults on the ‘factory’ image. From top to bottom: input

and polygonal approximations for τ = 2, 3, 6.

Digital Straightness and Polygonal Approximation 153

0

5

10

15

20

τ

2

4

6

8

10

12

14

16

d

⊥

0

0.2

0.4

0.6

0.8

1

f (τ, d

⊥

)

FIGURE 4.7: Quality o f approximation for the ‘factory’ image shown in

Fig. 4.6. The plot of IEF = f (τ, d

⊥

) versus the erro r tolerance τ and the

isothetic distance d

⊥

corresponding to criterion C

max

has been shown, and

that corresponding to criterion C

P

is quite similar. Note that ...