E-Mail: [e-mail]

1
?????? (4)

• ??????????????
• (1) ?????

2004.05.07
?????????? ???? E-Mail katto_at_waseda.jp
2
????????
3
??????? (1)

• ???????????????

???
????????
????
??
?????? (1/30?)

• RGB / YUV ??

Y
R
G
U
B
V
RGB?8???
YUV?8???
4
??????? (2)

• CCIR 601 ??????

444
422
420
Y
Y
Y
U
U
U
V
V
V
UV???????
UV?????????
YUV?????

• ???????? 420 ??????
• ???????? 422 ??????

5
??????? (3)

• ?????? (RGB?8?????????)

??
???
????
TV??
352x240
21Mbit/s
TV
720x480
83Mbit/s
HDTV
1920x1080
498Mbit/s
?????????
6
?????????

• MCDCT ??????????? (20?????????)

????????? MC (???? motion compensation) ??????
??? DCT (???????? discrete cosine transform)
Q ?????????????????
7
?????????

• ?????????????????

8
?????????
????????

• DCT

????
??????? ?????????????? (???? 0.9 )
????
????
DCT (????????)
????????????????
????????????? (??????)
9
?????????
???? (1)

• DCT???????

??????
????
KLT, DCT, DFT ?????????
KLT ???????????? DCT ??????????? KLT???????????
?? ?????????? 8x8 ??? ?DCT????
SIZE
????? ???????
10
?????????
???? (2)

• Wavelet ?? (??)

h0(n)
LLL
2
h0(n)
2
h1(n)
h0(n)
LLH
2
2
x(n)
h1(n)
LH
2
h1(n)
H
2
2???????????????
LL
LH
H
?? ??????????? ?? ??????????????
???????
11
?????????
???? (3)

• DCT ? Wavelet ???

??????
DCT, Wavelet ??????
????
11
r0.95
OPTIMUM (
)
10
DCT(16)
DCT(8)
9
DCT(4)
8
GAIN (dB)
7
6
5
Wavelet
? ??CQF (16tap)
4
? SSKF (5/3)
3
0
1
2
3
4
STAGES
Wavelet ??????

• DCT ?? (???) ??
• Wavelet ????? (JPEG-2000)

12
?????????
???????? (1)

• IP ??

I
P
P
P
P
P
P
???????? ???????????????? (???? 0.9 )
?????????????????

• I I ???? (????????)

• P P ???? (????????)

?????????????
13
?????????
???????? (2)

• IPB ??

I
B
B
P
B
B
P
???????????????? ??????????????? (???????????????)

• I I ???? (????????)

• P P ???? (?????)

• B B ???? (?????)

? ???????
14
?????????
???????? (3)

• ???????

I
B
B
P
B
B
P
???????
???????
?????TV????? (MPEG-2)

• ???? ?????????????????????????

• DCT ????DCT??????DCT

15
?????????
????????? (1)

• ???? (?????????)
• ????? (??????) ???????? (????????) ?????
• ????????????????????????

• ????
• ?????????????????????????????? (??????)
• ??????

? ????
? ????
-
????????
??????
??????
??
?? ????
????
????
? ????
16
?????????
????????? (2)

• ?????????
• ????????0.5 ????????????????????
• ????

??????
??????
??
0.5
0.5
??0.25
(?) 1/4???1/8??????????
17
?????????
????????? (3)

• ???????????
• ????????????????????????????????
• ????????

????????????
??????
??????
???????????
??????
??????
??? ???????? ????????????
???
18
?????????
????????? (4)

• ????

????? ????
???? ?????????
???????? ?????
???????? ?????
19
??????
20
?????? (1)
??
??
?????
??
??????
ITU-T
H.261
ISDN??????
1990?
64kb/s2Mb/s
H.263
????????????
1996?
??kb/s
H.263
???????????
1998?
??kb/s
MPEG-1
CD-ROM
1992?
ISO
1.5Mb/s
MPEG-2
???????
1995?
?Mb/s??Mb/s
MPEG-4
???????????
1999?
??kb/s
MPEG-2/H.262?H.264 (MPEG-4 Part 10)
?ISO?ITU-T????????
21
?????? (2)
82
84
86
88
90
92
94
96
98
00
02
MC (????)
DCT
MCDCT ? ????
???? ?????
B???? ?????
??????? ????????
H.120
Sub-rate
H.261
H.263 / H.263
ITU-T
1.5M
384K
64K - 1.5M
???, Internet, ???
ISDN
MPEG-2 / H.262
H.264
Joint (ITU-T ISO)
???DVD?HDTV
Internet, ???
MPEG-4
MPEG-1
ISO
Internet, ???
CD-ROM
22
?????? (3)

• ?????????

??
MCDCT
1/2??
IPB??
????????
?????
???
?????
H.261
?
-
-
-
-
-
-
H.263
?
?
?
-
-
-
-
MPEG-1
?
?
?
-
-
?
-
MPEG-2
?
?
?
?
?
?
-
H.263
?
?
?
?
-
?
?
MPEG-4
?
?
?
?
?
?
?
???????????? ????? (??)
23
ISO/IEC MPEG-4
24
MPEG-4 ???

• ???? (?????????????????)

??????? (????????) ?????????? ????????
(?????) ??????????? ????????
????????? ??????? (Wavelet ??)
???????????? ???????????? ???????????? ?????
?? ????????????
25
MPEG-4
????? (1)

• ????????

?? (?????)
?????
??
Hello
????
(?) ?????? (??????) ????????
26
????? (2)

• ?????????

??????? (CIF, QCIF, )
????? (x, y)
VOP?? (w, h)
???????????
?????????
??????????
27
????? (3)

• ????????????????????

???????
???????
??MB?????????
(1) ??????????? (2) ????????? (3) ??????
?????????
??MB?????????
(1) I-???? ????????????????????? DCT (2)
P-???? ??????0????????????? DCT
28
????? (4)

• ??????

(1) ???????
2??? (0,1) ??????
(2) ??????????
(0, 255) ??????????? (DCT)
(??) (R, G, B, A)?(Y, U, V, A) ??????
A ??????? (???????????????) A 0 ???????
(transparent) A 255 ???? (opaque) A 1 254
??????????? (????????)
29
ITU-T H.264 (MPEG-4 Part 10)
30
H.264???

• ??????? (MPEG-4 ? 70)

???????????????? (?????) ?????????
(Sub-macroblock prediction) 1/41/8 ???? (1/4,
1/8 pel interpolation) ???????? (Multiframe
prediction) ??????? (SAT sum of absolute
transformed differences) ???????? (Adaptive
intra prediction) ?????????DCT (Adaptive
block-size transform) ???????????? CABAC
(Context-based Adaptive Binary Arithmetic
Coding) ??????????????????? VCL Video Coding
Layer NAL Network Adaptation Layer ? RTP
Packetization
31
??????????
mode 1 16x16 block 1 vector
mode 2 8x16 block 2 vectors
mode 3 16x8 block 2 vectors
mode 4 8x8 block 4 vectors
0
0
1
2
3
mode 5 4x8 block 8 vectors
mode 6 8x4 block 8 vectors
mode 7 4x4 block 16 vectors
Sub-macroblock prediction
32
????????
?????????????
?????????
P
P
P
P
P
P
??????
?????????
Multi-frame prediction
33
SAT (???????)
SAD minimization (????????????)
??????
DCT???
??????
SAD minimization
?????????????? (SAD????DCT??????)
SAT minimization (????????????)
??????
DCT???
??????
????? ??
SAT minimization
???????? (??????)
SAD sum of absolute differences, SAT sum of
absolute transformed differences
34
??????????
mode 0 DC prediction mode 1 Vertical/Diagonal
prediction mode 2 Vertical prediction mode 3
Diagonal prediction mode 4 Horizontal
prediction mode 5 Horizontal/Diagonal prediction
I
A
B
C
D
???????
E
a
b
c
d
F
e
f
g
h
??????
G
i
j
k
l
H
m
n
o
p
?????
?
mode 0
??? (ABCDEFGH) / 8
mode 1
a (AB) / 2 e B b i (BC) / 2 f m C c
j (CD) / 2 d g h k l n o p D
35
CABAC
?????? ?????
????? (Binarization)
????
?????
B
Binarization ?? (unary)
A
C
index
binarization
0
1
?????????????? ?????????? ? ?????????????? ??????
1
01
A, B ????????? ? ????????????? ????????????? ? C
?????????
2
001
3
0001
4
00001
5
000001
vs. ?????? (??)
Context-based Adaptive Binary Arithmetic Coding
36
????????? (???)
??
??
CABAC
1015
??????????
5
???????
5
????????
5
R-D??? (??)
1015
??
30??
37
?????

• Rate-Distortion Optimization
• Multiple Distortion Coding
• Wyner-Zip Coding

38
R-D??? (1)
Lagrange ?????? (Rate-Constrained X)
?????
minimize
???????????????

• ??????? (D, R) ????????????????
• ????????????????????? (????)
• ??????????????? INTRA/INTER ????? (????)
• ??????????????? INTRA/INTER/SKIP ????? (????)
• ???????????????????? (????)
• ????????????????????????? (FastStreaming)

Rate-Distortion Optimization for Video
Compression, IEEE Signal Processing Magazine,
Nov.1998. ??
39
R-D??? (2)
????? (DCT??????)
(1) J ????
(2) ????????
(H.263)
(3) ??????????????????
(H.264)
40
R-D??? (3)
???
????
RD ???
???????? ????????? ?????????????????? ????
????? ????? ????????? ?????????????????
???????? ????????? ??? (??????????????????
?? ??) ??????????????????? ????? ?????????
??? (???????????????????? ?????????????????)
????? ???????
?? ?????????????????
41
Multiple Description Coding
????????? (??)
(?) Temporal scalability ?????????
I
B
B
P
B
B
????
????
Multiple Description Coding
? ?????????????????
2
??
1
????? (descriptions) ??????????
4
3
????????????
?? ????????????
42
Wyner-Ziv Coding
??????
decode
encode
Output (Y)
Input (X)
Distributed Source Coding (Wyner-Ziv Coding)
decode
encode
Input (X)
Y ( X?)
Output (Y)
sub- encode
sub- decode
Re- construction
p
?? ???? p (sub-information) ???????????