Digital Signal Processing Reference
In-Depth Information
Both father and mother wavelets are orthonormal at scale j :
Z
( 1
k ¼ n
f jk ðtÞf jn ðtÞdt ¼
(F.8)
0
otherwise
( 1
Z
k ¼ n
j jk ðtÞj jn ðtÞdt ¼
(F.9)
0
otherwise
F. 2 ANALYSIS EQUATIONS
When a function f ðtÞ
j þ 1, it can be
is approximated using the scaling functions only at scale
expressed as
N
c j ðkÞ 2 j= 2
2 j t kÞ
f ðtÞ¼
k ¼ N
Using the inner product,
Z
f ðtÞ 2 j= 2
2 j t kÞdt
c j ðkÞ¼< f ðtÞ; f jk ðtÞ >¼
(F.10)
Note that
N
p
2
fðtÞ¼
h 0 ðnÞfð 2 t nÞ
(F.11)
N
Substituting Equation (F.11) into Equation (F.10) leads to
Z
f ðtÞ 2 j= 2 N
N
p h 0 ðnÞf½ 2 ð 2 j t kÞndt
c j ðkÞ¼< f ðtÞ; f jk ðtÞ >¼
Z
N
f ðtÞ 2 ðjþ 1 Þ= 2
h 0 ðnÞfð 2 ðjþ 1 Þ t 2 k nÞdt
c j ðkÞ¼
N
Let m ¼ n þ 2 k . Interchange of the summation and integral leads to
Z
N
f ðtÞ 2 ðjþ 1 Þ= 2
h 0 ðm 2 kÞfð 2 ðjþ 1 Þ t mÞdt
c j ðkÞ¼
N
Z
N
c j ðkÞ¼
f ðtÞf ðjþ 1 Þm ðtÞdt
h 0 ðm 2
(F.12)
N
 
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