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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 3
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L
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?M0(…) 6= 0b
!f
M0(!) ?? O
@M0(!) = 1+O(j!j–)
– > 0b ?ik 2 Z+
P¤
Bk = max
!
flflM
0(!)¢¢¢¢¢¢M0(2k?1!)
flfl1=k < 2L?1=2,(13)
:? = L? 12?logBk > 0b5?’(!) =
1Q
j=1
m0(2?j!)μ
j?’(!)j? C (1+j!j)?12?" ;8! 2R (14)
£á
ìμjm0(!)j? 1+Cj!j–0b?j!j? 1
H
j?’(!)j? e
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j=1(2?jj!j)
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(1+e?i2?j!2 )
= Q
j
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= Q
j
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j
cos(2?j?1!)
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[
^’(!) = e?iL!=2
2
! sin(
!
2)
L
:
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f(2?kl!)
?
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P¤2kl0? j!j < 2k(l0+1)b5· = 2?(l0+1)k!
@j·j? 1bV7
y1M09
@M0(!) = 1+O(j!j–)?
B?¥2Tμ
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 13
1Q
l=l0+1
flflf(2?kl!)flfl = 1Q
j=0
flflf(2?(j+l
0+1)k!)
flfl
=
1Q
j=0
flflf(2?jk2?(l
0+1)k!)
flfl
=
1Q
j=0
flflf(2?jk·)flfl
=
1Q
j=0
jM0(2?j·)j
C
]
H:fl = log2 Bkμjf(!)j? Bkk8! 2R
l0Q
l=0
flflf(2?kl!)flfl? Bk(l0+1)
k
Bk+logj!jk
= Bkk ¢j!jlogBk = Cj!jfl
[?j!j > 1
Hμ
flfl
fl^’(!)
flfl
fl? Cj!j?L ¢j!jfl = C0j!j?L+log2 Bk < Cj!j?12?"
??(14)
T Vw¤^’ 2 L2b?v¥LD?l¥Bk|?á’ μ?ú¥?5?
èHarrf
á
ìμm0(!) = 12(1 + e?i!)b#L = 1,Bk = 1?
H(14)
T?¥" = 12b
V7
flfl
fl^’(!)
flfl
fl? C(1+j!j)?1

ì |
m0(!) =
1+e?i!
2
2?
a+be?i!¢
'h0 = a=2h1 = (2a+b)=2h2 = (a+2b)=2h3 = b=2.
?Hq(7)m0(0) = 1¤
a+b = 1:
????Hq(11)?k = 1
Hw¤
h2h0 +h3h1 = 0:
'
(a+2b)a+b(2a+b) = 0:
#μa+b = 1ab =?12.Ka¤a = 1+
p3
2b =
1?p3
2
6?B?
^a =
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 14
h0 = 1+
p3
4 ;h1 =
3+p3
4 ;h2 =
3?p3
4 ;h3 =
1?p3
4,
V
M0(!) = 1+
p3
2 +
1?p3
2 e
i!;

B1 = max!
flfl
flfl
fl
1+p3
2 +
1?p3
2 e
i!
flfl
flfl
fl =
1+p3
2 +
p3?1
2 =
p3 < 22?1:
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flfl
fl^’(!)
flfl
fl? C(1+j!j)?(2?log 32)
?2?log 32 > 1#D41Haarf
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f
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k
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fl^’(! +2k…)
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 O
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 15
’n(!) =
nY
j=1
m0(2?j!)′[?2n…;2n…](!)
A ’n(!) !?’(!)a:e:b

1f’n(t?l)g1S??"b
1R
1
’n(t)’n(t?l)dt
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= 12…
2n…R
2n…
nQ
j=1
jm0(2?j!)jeil!d!
= 12…
2n+1…R
0
nQ
j=1
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2
eil!d!
= 12… R2n…0 (
n?1Q
j=1
jm0(2?j!)j2)¢jm0(2?n!)j2 eil!d!
+ 12… R2n+1…2n… (
n?1Q
j=1
jm0(2?j!)j2)¢jm0(2?n!)j2 eil!d!
= 12… R2n…0 (
n?1Q
j=1
jm0(2?j!)j2)¢jm0(2?n!)j2 eil!d!
+ 12… R2n…0 (
n?1Q
j=1
jm0(2?j(! +2n…))j2 ¢jm0(2?n! +…)j2 eil(!+2n…)d!
= 12… R2n…0 (
n?1Q
j=1
jm0(2?j!)j2)¢(jm0(2?n!)j2 +jm0(2?n! +…)j2)eil!d!
= 12… R2n…0 (
n?1Q
j=1
jm0(2?j!)j2)eil!d!
= ¢¢¢ = 12… R4…0 jm0(!=2)j2eil!d!
= 12… R2…0 jm0(!=2)j2eil!d! + 12… R4…2… jm0(!=2+…)j2eil!d!
= 12… R2…0 eil!d!
= –l;0:
?N ?^w¤R ’n(t?m)’n(t?l)dt = –m;lb

2á
ì£
ü
j?’n(!)j? C(1+j!j)?12;? > 0 (15)
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C?G ??n;!b
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flfl
fl2?n sin !2=sin(2?n?1!)
flfl
fl
L ¢ nY
j=0
flflM
0(2?j!)
flfl′
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 16
flfl
flfl 1
sin(2?n?1!)′[?…;…](2
n!)
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flfl? …
22
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flfl? 2?n…
22
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7
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Hμ
nQ
j=0
jM0(2?j!)j
=
kmQ
j=0
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km+qQ
j=km+1
jM0(2?j!)j
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mQ
j=0
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mQ
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flflf(2?jk!)flfl? Bkm
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 17
1
2…
Z +1
1
j?’n(!)j2eil!d! = –l;0
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1
2…
Z +1
1
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 18
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 19
£
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r
P¤suppf ‰ [?r;r].:Ij;k = [?2jr?k;2jr?k]?j < 0; sl
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jf(t)j¢j’(2jt?k)jdt
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2j kfk21 ¢2r¢P
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k
R
Ij;k
j’(t)j2 dt
= 2rkfk21P
k
R+1
1 ′Ij;k (t)j’(t)j
2 dt
= 2rkfk21
+1R
1
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k
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 20
?(18)
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P¤?j < j0
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kPjf0k <?2:
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kfk?kPjf0k+kPjf0?fk <?
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 21
P
k
flfl
flR+1?1 f (t)2j2’(2jt?k)dt
flfl
fl
2
= P
k
flfl
fl 12… R+1?1?f (!)2?j2?’(2?j!)eik2?j!d!
flfl
fl
2
= 12… P
k
flfl
flflR2j+1…0 P
n
f (! +2j+1…n)?’(2?j! +2…n)eik2?j(!+2j+1…n).p2j+1…d!
flfl
flfl
2
= 12… R2j+1…0
flfl
flflP
n
f (! +2j+1…n)?’(2?j! +2…n)
flfl
flfl
2
d!
= 12… R2j+1…0 P
n;l
f (! +2j+1…n)?f (! +2j+1…l)?’(2?j! +2…n)?’(2?j! +2…l)d!
= 12… P
n;l
R2j+1…(n+1)
2j+1…n
f (!)?f (! +2j+1…(l?n))?’(2?j!)?’(2?j! +2…(l?n))d!
= 12… P
n;l
R2j+1…(n+1)
2j+1…n
f (!)?f (! +2j+1…l)?’(2j!)?’(2?j! +2…l)d!
= 12… P
l
R+1
1
f (!)?f (! +2j+1…l)?’(2?j!)?’(2?j! +2…l)d!
= 12… R+1?1
flfl
fl?f(!)
flfl
fl
2j?’(2?j!)j2 d! + 1
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P
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R+1
1
f(!)?f(! +2j+1…l)?’(2?j!)?’(2?j! +2…l)d!:
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< Pjf;Pjf >=< f;P?j Pjf >=< f;Pjf >=< f;f1 >= 0:
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k
X
k
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 22
+YPjf0μ
BkPjf0k2? Pk j < Pjf0;’j;k > j2
= Pk j < f0;Pj’j;k > j2
= Pk j < f0;’j;k > j2
= 1=2…R1?1j?’(2?j!)j2j?f0(!)j2d!:
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l ?? ??j !1
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’(!) =
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j=1
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Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 23
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:
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m0(!) =?’(2!)?’(!) = (1+e
i!)(2+e?2i!)
2(2+e?i!),
1 ??¥2…?
ùf
??
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 p3ZEb/

ì)
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ZEBá
ì I
n ?/¥Y}V?
·0(t) = ′[?1=2;1=2](t);
·n+1(t) = Pk hk·n(2t?k);n = 0;1;¢¢¢,
?

Y}V?f·ngμK5á
ì?
Z?(6)Y} V3b? ?6¥Hq/ V
[£
ü?·n(!) !?’(!),·n(t) ! ’(t)L2?b £
ü Vn
C ?,pp 107-108.
??
E?1Subdivision
ElossC[ -üX$ |
ì
ù?b
?fhkgμμK¥

H V[°¤ú ?¥ p3b
ZE=
!
’(t) =
N2X
k=N1
hk’(2t?k); (20)
?? ?16á
ì V[’(0) = 1,'
X
k
’(t?k) =?’(0) = 1,(21)
?? ?17supp’ ‰ [N1;N2].#?
?oμ’(N1 +1);’(N1 +2);¢¢¢ ;’(N2?1) V
d
,b? V?(20)#(21)·B p3b
? ?m=2¥???N1 < m=2 < N2,?(20) V

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N2X
k=N1
hk’(m?k):
×ˉ

V?á
ì V[ú ?19
’(t)t = m=2j?"¥=é?
¥
′b
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 24
9.lllooofff

I
n??MRA'V0iS??b??Vj ‰ Vj+1 ?j# V?lWj1VjVj+1?
¥???'
Vj+1 = Vj 'Wj:
¨Qj:L2(R)?Wj¥g?
0
Qj,L2(R) ! Wj:
1?0 bWWj,á
ìμ
??? ? ? ?: ?j,μ
(1) Wj?Wj+1,
(2) f(t) 2 Wj? O??f(2t) 2 Wj+1.
£
1 ?f 2 Wj;g 2 Wj+1??Wj ‰ Vj+1;Vj+1?Wj+1¤< f;g >= 0,#
1?
?b

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Vj+1.?f(t) 2 Vj+1,
[f(2t) 2 Vj+2,#f(2t) 2 Wj+1b
Q- V ?
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^Wj¥S??".?? -B? ?¥

2?f (t) 2 Wj
Hμf (2?jt) 2 W0
[
f?2?jt¢ =
X
k
ck?0;k(t);ck =
Z
f?2?jt¢?(t?k)dt;
V7
f(t) =
X
k
ck2?j2?j;k(t)
Vμf?j;kgL?V?
a
üf?j;kgk2Z
^Wj¥b
? -B? ?¥
1w¤Wj?Wj0;j 6= j0b?Vj+1 = Vj 'Wj¤VJ+1 = V?J J'
j=?J
Wj#
8f 2 L2(R)μ
PJ+1f?P?Jf =
JX
j=?J
X
k
< f;?j;k >?j;k:
7J !1i?MRA¥?é
2¤
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 25
f =
X
j;k
< f;?j;k >?j;k:
#f?j;kgj;k2Z
^L2(R)¥S??b
???lllW0¥
3?í??1(
)lo
mother wavelet.
/
á
ì)
8"/lof
b
??? ? ? ?
!’ 2 L2(R)1f
5g 2 L2(R);g?V0? O??
[?g;?’](!) =
X
k
g(! +2k…)?’(! +2k…) = 0 ;a:e,(22)
£?g;’ 2 L2(R)
H[?g;?’] 2 L1[0;2…] O(22)?¥í k)
^ '
l ?¥?
^y1
Z 2…
0
X
k
j?g(! +2k…)j¢j’(! +2k…)jd! =
Z +1
1
j?g(!)’(!)jd!?jjgjj¢jj’jj:
 ?k 2 Zá
ìμ
hg;’0;ki = 12… R+1?1?g(!)?’(!)eik!d!
= 12… R2…0 P
n
g(! +2n…)?’(! +2n…)eik(!+2n…)d!
= 12… R2…0 [?g;?’](!)eik!d!
[hg;’0;ki
^L1[0;2…]
 V¥f
[?g;?’]¥Fourier"
.
?g?V0
Hhg;’0;ki = 0;8kyN[?g;?’](!) = 0; a:e:
Q- ?[?g;?’] = 0; a:e:5hg;’0;ki = 0V7 ?f = P
k
ck’0;k 2 V0μhg;fi =
0'g?V0b

ìL?f

@S(’) = V0 O
’(!) = m0(!2)?’(!2)jm0(!)j2 +jm0(! +…)j2 = 1; m0(0) = 1:
n5ùsf 2 W0?
Há
ìμ
f 2 V1f?V0:
??B?Hq
üM?MV
U? ?1i2…?
ùf
m(!)
P¤
f(!) = m(!
2)?’(
!
2):
??=?HqD -B? ?w¤
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 26
0 = [?f;?’](!)
= P
k
f(! +2k…)?’(! +2k…)
= P
k
m(!2 +k…)?’(!2 +k…)m0(!2 +k…)’(!2 +k…)
= P
k
[m(!2 +2k…)m0(!2 +2k…)j?’(!2 +2k…))j2
+m(!2 +(2k +1)…)m0(!2 +(2k +1)…)j?’(!2 +(2k +1)…)j2]
= m(!2)m0(!2)P
k
j?’(!2 +2k…)j2 +m(!2 +…)m0(!2 +…)P
k
j?’(!2 +… +2k…)j2
= m(!2)m0(!2)+m(!2 +…)m0(!2 +…):
[
m(!)m0(!)+m(! +…)m0(! +…) = 0;a:e,(23)
?V
ü?ê_
(m0(!);m0(! + …))D_
(m(!);m(! + …))
^??¥.??m0(!)Dm0(! +
…) a:e:?]
H1
,i?
ùf
(!)
P¤
m(!) =?(!)m0(! +…); (24)
V?l1
(!) =
(?m(!+…)
m0(!) ; m0(!) 6= 0;
m(!)
m0(!+…); m0(! +…) 6= 0;m0(!) = 0:
} ?(23)
T¤
(!)+?(! +…) = 0;a:e:
[?(!) = P
k
ke?ik!2k = 0;8k.# V
(!) = e?i!”(2!);”(!)12…?
ùf
,(25)
Q-A ??(24)(25) ??¥m(!)
@(23)b

ì+Y |”(!) · 15μ
m1(!) = e?i!m0(! +…)
= e?i! 12 P
k
ˉhke?ik(!+…)
= 12 P
k
(?1)kˉhkei(k?1)!
= 12 P
k
(?1)k?1ˉh1?ke?ik!:
#á
ì:
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 27
m1(!) = 12
X
k
gke?ik!;
?
gk = (?1)k?1h1?k:
?¨FourierMD?lf

(!) = m1(!
2)?’(
!
2)
= e?i!2 m0(!2 +…)?’(!2):
/

ì£f?(t?k)k2Zg
^S??"b1No3£
ü
h?;
i
= 1;a:e:
7á
ìμ
P
k
flfl
fl(! +2…)
flfl
fl
2
= P
k
flflm
0(!2 +k… +…)
flfl2flfl?’(!
2 +k…)
flfl2
= P
k
hflfl
m0(!2 +2k… +…)flfl2flfl?’(!2 +2k…)flfl2 +flflm0(!2 +2k…)flfl2flfl?’(!2 +(2k?1)…)flfl2
i
= flflm0(!2 +…)flfl2P
k
flfl?’(!
2 +2k…)
flfl2 +flflm
0(!2)
flfl2P
k
flfl?’(!
2?… +2k…)
flfl2
= flflm0(!2 +…)flfl2 +flflm0(!2)flfl2
= 1
1£f?0;kg
^W0¥á
ì3£ ?if 2 W0iflkg2 l2
P¤
f(t) =
X
k
dk?0;k(t),(26)
?(24)(25)f VV
U1
f(!) =,(!)(!)
?
2…R
0
j”(!)j2d! = 2
…R
0
j?(!)j2d!b
??f 2 V1;f = P
k
fk’1;k OμP
k
jfkj2 = kfk2b?
H?f(!) = m(!=2)?’(!=2)?¥?]
?
ùf
m,μ
2…Z
0
jm(!)j2 d! = 2…
X
k
jfkj2 = 2…kfk2:
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 28
?(24)μ
2…R
0
jm(!)j2 d!
=
2…R
0
j?(!)j2jm0(! +…)j2 d!
=
…R
0
j?(!)j2jm0(! +…)j2 d! +
2…R

j?(!)j2jm0(! +…)j2 d!
=
…R
0
j?(!)j2jm0(! +…)j2 d! +
…R
0
j?(! +…)j2jm0(! +2…)j2 d!
=
…R
0
j?(!)j2 d!
#μ
2…R
0
j”(!)j2 d!
= 2
…R
0
j?(!)j2 d!
= 2
2…R
0
jm(!)j2 d!
= 4…kfk2 < +1:
[f VV
U1(26)¥?
T ?fdkg1”(!)¥Fourier"
b
8[
á
ì£
ü

??? ? ? ?19
!fVjgj2Z1L2(R)¥s’1S??f
 O2…?
ùf
m0(!)
@
m0(0) = 1jm0(!)j2 +jm0(! +…)j2 = 1;
[#?’(!) = m0(!2)?’(!2)b?l?(t)1
(!) = e?i!2 m0(!
2 +…)?’(
!
2) (27)
5f’j;k(t)gj;k2Z
^L2(R)¥S??b
? μ

?é¥f

^?·B¥?]¥?D? VMμB?
11¥2…?
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0‰(!),(!) = ‰(!)(!)bnDaubechies,p,135b

ì V[ |‰(!) = ‰0eim!;m 2 Z;j‰0j = 1 ?
üM?(t)b
10??????lllooo¥¥¥ è è è000

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’(t) = ′[0;1](t);?’(!) = 1i!(1?e?i!)
[
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 29
m0(!) =?’(2!)?’(!) = 12(1+e?i!);
'h0 = h1 = 1lof

-
F
¥B?μ|
(!)
=?e?i!2 (1+e?i(!2 +…)2 )?’(!2)
= 1i!(1?e?i!2 )2
V7
(t) = ′[0;1
2]
(t)?′[1
2;1]
(t):
M?¥1"1
’(t) = ’(2t)+’(2t?1);?(t) =?(2t)+?(2t?1):

2Battle-Lemarie.
1?"Hf
Tf
?a??
¤¥bBQ
Hμ
’(t) =
(
1?jtj; jtj? 1;
0; ;
?
H
’(!) = 1i!(ei!2?e?i!2 )2 = (2! sin !2)2:
#μ
m0(!) = cos2 !2:
[?’;?’](!)
= P
k
j?’(! +2k…)j2
= P
k
sin2 !
2
(!2 +k…)2
·2
= sin4 !2 ¢
1
sin4 !2?
2
3
1
sin2 !2
·
= 1? 23 sin2 !2
= 13(1+2cos2 !2):
[’D
¥?
üM????"b
7
’#(!) =?’(!)p[?’;?’](!) = p3 4sin
2 !
2
!2(1+2cos2 !2)12
5f’#(t?k)gk2Z
3?
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^?|"¥b
N
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rof
1
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 30
m#0 (!) = cos2 !2
1+2cos2 !
2
1+2cos2 !
12
[
(!) = e?i!2 m#0 (!
2 +…)?’
#(!
2)
= p3e?i!2 sin2 !4
1+2sin2 !
4
1+2cos2 !2
·1
2
1
1+2cos2 !4
·1
2,
B?NQ
H V¨FourierMD?lf
’(t)
’(!) = e?i?!2
2
! sin
!
2
N+1
?? = 0?N= 
? = 1?N=
}
b
L=
?N1 
H
’(t) = ′[?1
2;
1
2]
¢¢¢¢¢¢?′[?1
2;
1
2]
(t)(N +1Q )
?N1
}
H
’(t) = ′[?1
2;
1
2]
¢¢¢¢¢¢?′[?1
2;
1
2]
(t? 12)
^?|"s
NQ[
T?8
?CN?1¥f
'NQ"Hf
b
??m0(!) = ei[N+12 ]!(1+e?i!2 )N+11 ??[
T#’(t)¥
Z?1
’(t) =
8
>><
>>:
2?2M
2M+1P
j=0
Cj2M+1’(2t+M?j); N = 2M;
2?2M?1
2M+2P
j=0
Cj2M+2’(2t+M +1?j); N = 2M +1:
N?[?’;?’]¥Vr
T9 V[A
Uby7 V¨??V?f
’#(t)b V[
£
ü’#(t)μ·
hb

3Meyer
!”(t)
^C1f

@
”(t) =
(
0; t? 0;
1; t? 1;
”(t) +,(1?t) = 1b μμK;á?¥ è01”1(t) = t;0 < t < 1,”2(t) = sin2(…t2 );0 <
t < 1,[
!”3(t) = t4(35?84t+70t2?20t3)?b
?l
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 31
’(t) =
8
><
>:
1; j!j? 23…;
cos[…2”( 32…j!j?1)]; 23…?j!j? 43…;
0; ;
5μ[?’;?’](!) = 1:b
Y
L
?|"[#?
ù?éo3£
j?’(!)j2 +j?’(2…?!)j2 = 1;8! 2 [0;2…]:
?0? !? 2…3
H4…3? 2…?3? 2…

TA ?? ?b] ? V£4…3? !? 2…¥ f?b
?2…3? !? 43…
Hμ
j?’(!)j2 +j?’(2…?!)j2
= cos2[…2”( 32…!?1)]+cos2[…2”( 32…(2…?3)?1)]
= cos2[…2”( 32…!?1)]+sin2[…2”( 32…!?1)]
= 1:
[’
3?B???MRAb
?
rof
m0(!)á
ìμ
m0(!) =
X
k
’(2! +4k…):
Kaá
�
(!) =
8>
<
>:
e?i!2 sin[…2”( 32…j!j?1)]; 2…3?j!j? 4…3 ;
e?i!2 cos[…2”( 34…j!j?1)]; 4…3?j!j? 8…3 ;
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:
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n5ó¥b
V
ro m0(!) 7
Sbá
ìXμ
m0(0) = 1; jm0(!)j2 +jm0(! +…)j2 = 1; (10)

m0(!) =
1+e?i!
2
N
M0(!),(12)
??Haarlo??N = 1á
ì?? |N? 2bN| e?’¥?5?.
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 32

ì?? ??|"¥f
loy7L?fhkg?oμμK?d
,i O1
L
?
'
!μ
Z?
’(t) =
N2X
k=N1
hk’(2t?k):
üV
üM’1(t) = ’(t+N1)a

T?1
’1(t) =
N2?N2X
k=0
hk+N1’1(2t?k):
[á
ì?^
!hk = 0?k < 0?
Hμ[
T
H(z) = 12
X
k
hkzk:
5á
ìμ
m0(!) = H(e?i!)
O
H(z) =
1+z
2
N
Q(z) ;
Q(z)1
L"
[
T OQ(1) = 1;Q(?1) 6= 0:
C)
8"?(10)
T¤[
TQ(z)b
??Q(e?i!) = Q(ei!)
[jQ(e?i!)j2 = Q(e?i!)Q(ei!)1!¥
}f
#
^cos!¥[
Tb ?¨1?cos!2 = sin2 !2
?
^sin2 !2¥[
T:-1P(y);y = sin2 !2b
y1
1+e?i!
2
·N

1+ei!
2
·N
=?1+cos!2 ¢N
=?cos2 !2¢N
= (1?y)N,
?(10)¤
(1?y)NP(y)+yNP(1?y) = 1; P(y)? 0 8y 2 [0;1],(28)
1 p3}
Z?(28)5óB?£ù2Tb
??? ? ? ?(Bezout):
!P1P2
^Q
1n1n2¥o
í[
T5i·B¥Q
sY??Vn2?
1n1?1¥[
Tq1q2
P¤
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 33
p1(t)q1(t)+p2(t)q2(t) = 1:
£nDaubechies p.p.169-170.
?P(y)¥Q
??VN?1
H?Bezout? ?3
^·B¥|(28)?1
P(y) = (1?y)?N?yN(1?y)?NP(1?y);
?Taylor? ??=[¥Q
9ú?N?1#N?1Q[
T31
P0(y) =
N?1X
k=0
CkN+k?1yk:
B?3P(y) V1
P(y) = P0(y)+yN (y):
} ?(28)¤
(y)+ (1?y) = 0:
7 (y) = R(12?y)5μR(y) =?R(?y)b
[B?3
P(y) =
N?1X
k=0
CkN+k?1yk +yNR(12?y):
?á
ì?R(y) · 05μ
flflQ(e?i!)flfl2 = N?1X
k=0
CkN+k?1
sin2 !2
·k
:

ì31 p[
TQ(z)bRiesz;óB?/?ZEb
Riesz??? ? ? ?
!a0;a1;¢¢¢ ;aM1
L
aM 6= 0
P¤
A(!) = a02 +
MX
k=1
ak cos(k!)? 0;! 2R:
5i
L"
[
T
B(z) =
MX
k=0
bkzk
P¤
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 34
flflB?e?i!¢flfl2 = A(!):
£ I
n2MQ[
T
PA(z) = 12
MX
k=?M
ajkjzM+k;
A ?μ
PA(z) = zMA(!);z = e?i!

PA(z) = z2MPA(1z) z 2 C:
y1aM 6= 0#PA(0) 6= 0'
,?
^PA(z)¥?b
?

?
Tá
ìw¤ ?z
^?51z9
^? Oy1fakg
^
L¥z9
^?b#á
ì¤
?
L?
r1;r2;¢¢¢ ;rk; 1r
1; 1r
2;¢¢¢ ; 1r
k;
ˉ?
z1;z2;¢¢¢ ;zj;z1;z2;¢¢¢ ;zJ;¢¢¢ ; 1z
1; 1z
2; 1z
J;¢¢¢ ; 1z
1; 1z
2;¢¢¢ ; 1z
J
:
'PA(z) V[s31
PA(z) = 12aM
KY
k=1
(z?rk)(z? 1r
k
)
!? JY
j=1
(z?zj)(z?zj)(z? 1z
j
)(z? 1z
j
)
!
K +2J = M.
?z = e?i!
H
flfl
flfl(z?zj)(z? 1
zj)
flfl
flfl = jzjj?1jz?zjj2
#á
ìμ
A(!) = jA(!)j = jPA(z)j = 12 jaMj¢
KY
k=1
1
jrkj
!

JY
j=1
1
jzjj2
!

flfl
flfl
fl
KY
k=1
(z?rk)
flfl
flfl
fl
2

flfl
flfl
fl
JY
j=1
(z?zj)(z?zj)
flfl
flfl
fl
2
[B(z) V |1
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 35
B(z) =
1
2
flfl
flfl
flaM
KY
k=1
1
rk
JY
j=1
1
z2j
flfl
flfl
fl
!12

KY
k=1
(z?rk)¢
JY
j=1
(z?zj)(z?zj):
B¥Q
1K +2J = M,A ?B?
^·B¥b|ê |
a?¥Sy0
P¤Q(1) = 1b
è?N = 2
H
flflQ(e?i!)flfl2 = 1X
k=0
Ck2+k?1(sin2 !2)k = 1+2sin2 !2 = 42?cos!
#a0 = 4;a1 =?1b?Riesz? ?PA(z)1
PA(z) = 12(?1+4z?z2) =?12(z?(2?p3))(z?(2+p3)):
ê |ê??ê??¥?2+p3T1r15μ
B(z) = (12 12+p3)12(z?(2+p3)) = 11+p3(z?(2+p3))
?"
Q(z) =?B(z) = 1?
p3
2 z +
1+p3
2,
V7
H(z) =
1+z
2
2
Q(z) = 12
1+p3
4 +
3+p3
4 z +
3?p3
4 z
2 + 1?
p3
4 z
3
!;
Dá
ì[ -¤?¥M]b
0 0.5 1 1.5 2 2.5 3?0.4
0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1?0.5 0 0.5 1 1.5 2?1.5
1
0.5
0
0.5
1
1.5
2
Figure 1,Daubechies 4-"
¥f
’(Pm)lo?(·m).
?
1??Q¥Q
1N? 1#H(z)¥Q
12N? 1'
ro ¥"
¥é
12Nb
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 36

2Riesz¥
E ?

^/?¥?
#?}
Z?¥ p?b?B?o
¨í
ZE p¤b

3 ?:N
H¥f
1’N(t)5
¥|"1[0;2N +1]b?f
’N(t)YV(27) V/
f
N(t)
¥|"
^
I
1$

4??(10)?
^S??¥A1Hqf’N(t? k)gk2Z
^?1S??"
.à
^Riesz?
31éB?¥£
Lb
Lawton£
ü?m0
^ ??[
T
Hf?j;kg
^? O'μ
??? ? ? ?20
!m0(!)1 ??[
T
@?
T(10)'
m0(0) = 1; jm0(!)j2 +jm0(! +…)j2 = 1:
?í ke
1Q
j=1
m0(2?j!)?l?|"f
’(t)?(27)?lf
(t)'
(t) =
X
k
(?1)kˉh?k+1’(2t?k)
5 ?f 2 L2(R)μ
X
j;k
j < f;?j;k > j2 = kfk2 (29)
'f?j;kg(j;k)2Z2
^L2(R)¥? Ob
£££(i)?? ?8¥£
ü?Hq(10)w¤(11)? ?'
X
n
hnˉhn?2k = 2–k;0
(ii) ?mn 2 Zμ
X
k
(hm?2kˉhn?2k +(?1)m+nˉh?m+2k+1h?k+2k+1) = 2–m;n (30)
Y
L
?m;n]1
}
H'm = 2p;n = 2qμ
P
k
(h2p?2kˉh2q?2k +(?1)2p+2qˉh?2p+2k+1h?2q+2k+1)
= P
k
(h2kˉh2(q?p)+2k + ˉh2(q?p)+2k+1h2k+1)
= P
k
hkˉhk+2(q?p)
= 2–2(p?k);0 = 2–m;n
? f? V ?
¥£
ü.
(iii)
!f 2 C10 (R)b5 ?jμfhf;?j;kigk2Zfhf;?j;kigk2Z 2 l2b
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 37
??fμ?|"ir > 0
P¤suppf ‰ [?r;r]b:Ik = [?2jr?k;2jr?k]b5i
k > 0
P¤?jk1?k2j > K
HIk1\Ik2 = `b ?k 2 Zs3k = Km+q(0? q < K)b

ìμ
P
k jhf;’j;kij
2
2j P
k
R+1
1 jf(t)’(2
jt?k)jdt
·2
2j P
k
Rr
r jf(t)j
2 dt
·?Rr
r j’(2
jt?k)j2dt
·
kfk2P
k
R
Ik j’(t)j
2dt
kfk2
+1P
1
K?1P
q=0
R
IKm+q j’(t)j
2dt
kfk2
K?1P
q=0
R
[mIKm+q j’(t)j
2dt
kfk2 K ¢k’k2,
#fhf;’j;kigk2Z 2 l2b ?
V£fhf;?j;kigk2Z 2 l2b
(iv)?’(t) = P
k
hk’(2t?k)?(t) = P
k
(?1)k h?k+1’(2t?k)w¤’0;k (t)= 1p2 P
m
hm?2k’1;m (t)
0;k (t) = 1p2 P
m
(?1)m h?m+2k+1’1;m (t)b
[,?(30)¤
P
k
jhf;’
0;kij
2 +jhf;?
0;kij
2¢
= 12 P
k
P
m;n
h
m?2khn?2k +(?1)
m+n h
m+2k+1h?n+2k+1
¢hf;’
1;mih’1;n;fi
= 12 P
m;n
2–m;nhf;’1;mih’1;n;fi
= P
m
jhf;’1;mij2
?=??
T? p?DQ?
^ ??¥y1%?¥k1?mn¥?
^μKb?"á
ìμ
X
k
jhf;’0;kij2 =
X
k
jhf;’1;kij2?
X
k
jhf;’0;kij2:
?Nw¤ ?jμ
X
k
jhf;?j;kij2 =
X
k
jhf;’j+1;kij2?
X
k
jhf;’j;kij2
 ?J > 0, pa¤
J?1X
j=?J
jhf;?j;kij2 =
X
k
jhf;’J;kij2?
X
k
jhf;’?J;kij2 (31)
?i?,?f 2 C10 (R)?(17)
T?J !1
Hμ
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 38
X
k
jhf;’?J;kij2 ! 0:
?(19)
T¤
X
k
jhf;’J;kij2 = 12…
+1Z
1
flfl?’(2?J!)flfl2flfl
fl?f(!)
flfl
fl
2 d! +R
J
?RJ ! 0?J !1b
y1jm0(!)j? 1#j?’(!)j? 1b?
H9μ?’(!)! = 0) ??b?Lebesgue e?
l ??
?μ
lim
J!1
X
k
jhf;’J;kij2 = 12…
+1Z
1
flfl
fl?f(!)
flfl
fl
2d! = kfk2,
(31)?
7J !1'£¤(29)b
Ka, ?f 2 L2(R)¨
á? Vw¤
1£b
??Bc¥? ?5k?j;kk = 18j;k 2 Z
H? Of?j;kg(j;k) 2 Z2?1S
??b?
HVk?j;kk = k?k¤k?k = 1b
[? ?20¥Hq/ ?k?k = 1
5f?j;kg
^L2(R)¥S??b
Cá
ì)
Daubechieslo¥;á?b
m0(!) = (1+e
i!
2 )
NM0(!);
?M0(!)
@
jM0(!)j2 = PN(sin2 !2) =
N?1X
k=0
CkN+k?1(sin2 !2)k,(32)
???lll:
!fi? 0;fi = n+fl;0? fl < 1;n 2 Z+b?f 2 Lipfi ?
flflf(n)(t+h)?f(n)(t)flfl? Cjhjfl ;8jhj? 1:
??? ? ? ?21:
!?’(!)
@
j?’(!)j? C(1+j!j)?1?fi;8! 2R:
5’ 2 Lipfi.
£££A ’ 2 L1#μ
’(t) = 12…
Z
’(!)ei!td!;
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 39
’(n)(t+h)?’(n)(t) = 12…
Z
’(!)ei!t(i!)n(eih!?1)d!
V
flfleih!?1flfl?jh!jfl
w¤
flfl’(n)(t+h)?’(n)(t)flfl? Cjhjfl Z flflfl^’(!)flflflj!jfi d!? Cjhjfl,
1?[
TPN(y)á
ìμ
??? ? ? ?[
TPN(x)
@
(1)?0? x? y
Hμ
x?N+1PN(x)? y?N+1PN(y);
(2)?0? x? 1
Hμ
PN(x)? 2N?1(max(1;2x))N?1,(33)
£
1
x?(N?1)PN(x) =
N?1X
k=0
CkN?1+kx?(N?1?k)
A ?
^x¥hf

2??PN(x)
@
xNPN(1?x)+(1?x)NPN(x) = 1
7x = 1=2¤
PN(12) = 2N?1:
?x? 12
Hμ
PN(x)? PN(12) = 2N?1:
7?x > 1=2
Hμ
x?N+1PN(x)? 2N?1PN(12)
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 40
[
PN(x)? (2x)N?1 ¢2N?1:
??? ? ? ?:Bk = sup
!
flflM
0 (!)¢¢¢M0
2k?1!¢flfl1=k ?M
0 (!)
@(32)b5
B1 < 2N?1;B2 < 2N?1N
 0:18b
£££?k = 1
Hμ
B1 = sup!
flfl
flflN?1P
n=0
CnN+n?1?sin2 !2¢n
flfl
flfl
12
N?1P
n=0
CnN+n?1
12
<
2N?1
N?1P
n=0
CnN?1+n2?n
12
=?2N?1PN?12¢¢12 = 2N?1:
?k = 2
Hμ
jM0 (2!)j2 = PN?sin2 !¢;sin2 ! = 4sin2 !2
1?sin2 !2
·;
[
B2 = sup
!
jM0 (!)M0 (2!)j12 = sup
0?y?1
jPN (y)PN (4y(1?y))j14,(34)
?0? y? 1212 +
p2
4? y? 1
Hμ
y4y(1?y) 2
0; 12
:
#(34)??(33)μB?y0??V2N?17
:/¥B?y0??V2N?1 ¢2N?1
[
?
Hμ
PN (y)PN (4y(1?y))? 23(N?1):
7?12? y? 12 +
p2
4
H?(33)¤
PN (y)PN (4y(1?y))? 2N?1 (2y)N?1 ¢2N?1 (8y(1?y))N?1
26(N?1)(y2(1?y))N?1
26(N?1)(4=27)N?1(y2(1?y)? 4=27?0? y? 1)
Lecture Notes on Wavelets,Chapter 4,by D.Q,Dai,2003 41
Ka¤
B2? (26 ¢ 427)N?14
= 2(2?34 log3)(N?1)
< 2N?1N

@
N < (34 log3?1)(N?1)
734 log3?1 … 0:1887;# V |? = 0:18.
??? ? ? ?22Daubechieslo’N(t)á
ìμ
flfl
flc’N(!)
flfl
fl? C(1+j!j)?1N
? > 0
V7’N(t) 2 Lip(?N).