?????VGA ?????

1
??????????

• ?????VGA ?????
• MPEG??

2
?????

• Analog signal- composite TV signal- RGB --gt
  YIQ (Y??, I,Q ??)
• Digital signal- pixel-based (gray level,
  color)- RGB

3
????

• ????
• 25 f/s(???25? ??)
• ????625?,??????312.5?,??25???????,287.5??????
• ??????43(625x835??,????572x676)?
• ??????25x835x625 /26.5MHz
• ????
• ?????????,?RGB????????Y????????
• NTSC?????YIQ,???????????????
• PAL?????YUV,??????????????

4
????
RGB, ????????? ??????
CMYK,???????? ?????????????
HSB, CIE???? (??????) ?????????
5
Additive colors
Cyan
Yellow
Magenta
6
Subtractive colors
Green
Red
Blue
7
CMYK model

• ?????????????????
• ?????????? (C)????(M)??? (Y)???(K)

8
CIE color space
9
RGB?YUV

• Y0.299R0.587G0.114B
• U0.493(B-Y), V(R-Y)
• Y 0.299 0.587 0.114 R
• I -0.147 - 0.289 - 0.436 G
• Q 0.615 - 0.515 0.100 B

10
RGB?YIQ

• I V cos33 - U sin33
• Q V sin33 U cos33
• Y 0.299 0.587 0.114 R
• I 0.596 - 0.275 - 0.322 G
• Q 0.212 - 0.523 0.311 B

11
???????
????
????
????
????
I/O??
Frame Buffer
????
????
????
12
VGA???

• VGA(Video Graphics Adapter)?????VGA?? D-Sub ????
  15 pin??,?- R,G,B ???- H-sync ??????(controls
  begin/end of each scan line)- V-sync
  ??????(assembles scan lines to form a frame
  display)

13
H-sync and V-sync
V-sync
Vertical-retrace
H-sync
Horizontal-retrace
14
VGA???

• VGA 640x480, 16 colors
• SVGA 800x600, 16 bit colors
• H-sync frequency 31.5kHz, 35.5kHz, 48kHz, 82kHz
• V-sync frequency 60Hz, 72Hz, 120Hz (3D graphics)
• Multi-sync??

15
????

• Digital TV????????????
• ??CEA(Consumer Electronics Association??????)?????
  ??????????????(HDTV)?????????(EDTV)?????????(SDTV
  )?

16
???????????????

• ???????????,???????50??
• ???????/??????(DTV Set-Top Box???????),???????????
  ????
• ?????????????????????????

17
?????????

• ????????
• ??????????????,???????????,?????????,?????????????
  ???
• ??????0???1????????,????????,??????????????
• ???????
• ???????????????
• ?????525???????1080?
• ?6MHz(NTSC??)????HDTV??
• Dolby AC-3?5.1??????
• ?????
• ???? ???????(Pay Per ViewPPV) ???????(Movie On
  Demand,MOD)?????(Karaoke On Demand,KOD)?????(News
  On Demand,NOD)??????????????????????(Internet)????
  ??

18
???????????

• ?????????????,??????????????(????),????????(Cable)
  ??????????
• ???,???????89?6?27??,?????????(???????????)???????
  ???????????????????????
• ????????????????,??????????????????,??169?????AC-
  3 5.1????????????????????,??43????
• ???2001??????????????,??2006?????????????????????

19
High-definition TV(HDTV)?????
20
?????????

• ??????? (transform-based coding)
• ?????(spatial domain)?redundancy
• ?????(temporal domain)?redundancy

21
????

• Moving Picture Experts Group
• MPEG-1 VCD
• MPEG-2 DVD
• MPEG-4
• MPEG-7 (???)

22
MPEG-1?????

• Video resolution 320x240, 30 frames/sec
• ???? JPEG (?????)
• ???? Motion compensation(?????)
• ???? Entropy coding

23
??????

• ??????? intra (I) pictures, predicted (P)
  pictures, and bidirectionally interpolated (B)
  pictures.
• I ?????(every 12-15 frames)
• P ??????(I or P)??motion vector??
• B ??I,P ????????

24
I,P,B?????
25
Motion Compensation

• ?????? 16 x 16 ???, ??macroblock.
• Compute motion vector by minimizing

26
MPEG-2 ????

• Frame DCT and Field DCT