M P E G MPEG 1 Overview 제어인식연구실 이 찬 우 10월 19일 1998년.

Presentation on theme: "M P E G MPEG 1 Overview 제어인식연구실 이 찬 우 10월 19일 1998년."— Presentation transcript:

1 M P E G MPEG 1 Overview 제어인식연구실 이 찬 우 10월 19일 1998년

2 Overview MPEG Moving Picture Experts Group
Known as ISO/IEC Standard , ISO 11172 System, Video, Audio 1.2Mbits/sec, 352 x 240 resolution at 30Hz is often used Video quality is comparable to VHS Random access, GOP(group of pictures) Realtime decoding For storage media; CDROM, DAT(Digital Audio Tape) 제어인식연구실

3 MPEG Decoding System MPEG System : Synchronization Video Audio
Figure 1 : MPEG Decoding System 제어인식연구실

4 MPEG digital video coding Technique
Intra-frame coding technique Spatial correlation between nearby pels within same image DCT on image blocks of 8x8 pels Inter-frame coding technique Temporal prediction, motion compensated prediction between frames Sub sampling and Interpolation 4:2:0 format 제어인식연구실

5 Intra-frame coding technique
DCT Quantize Zigzag scan Figure 2 : Variance distribution of DCT-coefficients Figure 3 : Zigzag scan order 제어인식연구실

6 Inter-frame coding technique
Block size : 16 x 16 Search Window Motion Vector Figure 4 : Block matching approach for motion compensation 제어인식연구실

7 Subsampling and Interpolation
The human eye is more sensitive to changes in brightness than to chromaticity changes Divide the images into YUV components 4: 2: 0 format Figure 5 :B picture encoding procedure 제어인식연구실

8 Picture type I Picture (Intra) P Picture (Predictive)
프레임 내 부호화 영상 GOP(Group of Pictures)의 독립성 확보 P Picture (Predictive) 프레임간 순방향 예측 부호화 원화상과 같은 순서로 부호화 B Picture (Bi-directionally) 쌍방향 예측 부호화 D Picture DC only, Fast Forward & Fast Rewind 제어인식연구실

9 I Picture Figure 6 :I picture encoding procedure 제어인식연구실

10 P Picture Figure 7 :P picture encoding procedure 제어인식연구실

11 B Picture Figure 8 :Test picture (previous/current/future)
Figure 9 :B picture encoding procedure 제어인식연구실

12 Picture coding/display order
Figure 10 : A group of consecutive pictures in video sequence 제어인식연구실

13 Figure 11: (A) Frame at time instance N to be coded.
제어인식연구실

14 Figure 11: (B) Frame at instance N-1 used for prediction of the content in frame N (note that the motion vectors depicted in the image are not part of the reconstructed image stored at the encoder and decoder). 제어인식연구실

15 Figure 11: (C) Prediction error image obtained without using motion compensation - all motion vectors are assumed to be zero. 제어인식연구실

16 Figure 11: (D) Prediction error image to be coded if motion compensated prediction is employed.
제어인식연구실

17 MPEG video sequence Figure 12 :MPEG Video sequence
Figure 13: Macroblock 제어인식연구실

18 Reference 정제창, 그림으로 보는 최신 MPEG, 1997
ISO 제어인식연구실