Digital Signal Processing Reference
In-Depth Information
x 10
6
3
[19] Approach
[20] Approach
Proposed
2.5
r
f
s
2
1.5
1
0.5
0
0
20
40
60
80
100
120
Moment Order
Figure 4.
Number of additions for a 128×128 grey-scaled image.
3.4.3. Speed performance and comparison studies
The computation speed of the proposed method is compared with [19] and [20]. CPU elapsed
time is used in the evaluation process in all the performed numerical experiments. The codes
were all written in MATLAB7 and simulations were run with a 3GHz Intel Core2 with 2GB
RAM and the average time is used in the discussion. The images used for the experiments were
the Pepper and Lena images, as shown in Figure 5.
Table 4 shows the simulation time for GMs computation on the Pepper image of size 128×128
for orders of 5 to 55, in a step of 10. The same experiment was repeated on the Lena image of
size 512×512. The simulation times are shown in Table 5.
Moment order (
s
=
p
+
q
) [19]
[20]
Proposed method
5
0.4
0.39
0.388
15
1.12
1.104
1.05
25
2.03
1.97
1.81
35
3.28
3.14
2.82
45
5.15
4.87
4.32
55
7.96
7.48
6.63
Table 4.
CPU elapsed time in milliseconds for the 128×128 Pepper's test image.
