Information Technology Reference
In-Depth Information
db
wavelet and wavelet packet. The optimal wavelet decomposition tree expansion is
given below.
1
(9)
S
=
AAAA
4
⊕
DAAA
4
⊕
ADAA
4
⊕
DDAA
4
⊕
DA
2
⊕
D
1
When the length of video traffic prediction is set to 256 frames, the length of each
wavelet coefficient need to be predicted is shown in Table 1.
Table 1.
Wavelet Coefficients Information
coefficient Length of
wavelet
Coefficient Length of wavelet
to be predicted
Wavelet level
AAAA4
64
16
DAAA4
64
16
ADAA4
64
16
DDAA4
64
16
DA2
256
64
D1
512
128
Figure 2 shows wavelet packet decomposition and coefficients prediction of “News”
frame sequence. Figure 1(a) indicates prediction result of AAAA4 wavelet packet
coefficients. This wavelet packet coefficient reflects the trend of signal change. Pre-
diction performance of wavelet packet coefficients DAAA4, ADAA4, DDAA4, DA2
and D1 are shown respectively in Figure 1(b), 2(c), 2(d), 2(e), 2(f).
4
0.4
Real
Predicted
3.5
0.2
3
0
2.5
-0.2
2
-0.4
1.5
-0.6
Real
Predicted
1
-0.8
0.5
0
-1
0
2
4
6
8
10
12
14
16
2
4
6
8
10
12
14
16
AAAA4 wavelet coefficients
DAAA4 wavelet coefficients
(a) (b)
0.3
0.6
Real
Predicted
Real
Predicted
0.2
0.4
0.1
0.2
0
-0.1
0
-0.2
-0.2
-0.3
-0.4
-0.4
0
2
4
6
8
10
12
14
16
0
2
4
6
8
10
12
14
16
DDAA4 wavelet coefficients
ADAA4 wavelet coefficients
(c) (d)
Fig. 1.
Wavelet packet decomposition and coefficients prediction
