Table 7 Processing average time for each step of the preprocessing and the total time

Negative

5.93

4.66

Logarithmic transf.

9.11

8.37

Bilateral filter

12.59

10.13

Canny Algorithm

0.58

0.48

Morphological filtering

0.15

0.13

Projective integrals

0.61

0.51

Total preproc. time

29.0

24.29