7 - OnlineLecture7 LearningObjectives DataCompression...

This preview shows pages 1–10. Sign up to view the full content.

Mulitimedia Computing Online Lecture-7 Learning Objectives: Data Compression Compression JPEG Standard JPEG 2000 Video Compression Solution to Some Problems Some Recommended  Problems Instructor-in-Charge Dr. Mukesh Kumar  Rohil WILPD, BITS, Pilani Rajasthan Monday, March 15, 2010 1 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Discrete Cosine Transform (DCT) Equation for DCT : 2 M-1 N-1 (2x+1)u ╥ (2y+1)v ╥ H( u,v) = ——— C(u) C(v) h(x,y) cos ———— cos ———— √( MN) x=0 y=0 2M 2N Where 1/ √2 for γ =0 C( γ )= 1 for γ >0 M x N = Size of the block Monday, March 15, 2010 2 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7
Reverse Discrete Cosine Transform   Equation for this : 2 M-1 N-1 (2x+1)u ╥ (2y+1)v ╥ h(x,y) = ——— C(u) C(v) H(u,v) cos ———— cos ———— √( MN) u=0 v=0 2M 2N Where 1/ √2 for γ =0 C( γ )= 1 for γ >0 M x N = Size of the block Monday, March 15, 2010 3 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Data Compression  JPEG DCT based mode  (Sequential coding) Expanded Lossy DCT- based Mode  (Progressive  encoding) Lossless Mode Hierarchical Mode MPEG Coding Types of frames I, P, B and D frames Motion estimation Audio Coding  (T1.Ch6) PCM DPCM ADPCM -μ-Law Monday, March 15, 2010 4 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7
JPEG Compression Standard  … 4 Monday, March 15, 2010 5 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
JPEG Compression Standard  … 5 Main Steps in JPEG Image Compression   Transform RGB to YIQ or YUV and  subsample color.   DCT on image blocks.   Quantization.   Zig-zag ordering and run-length encoding.   Entropy coding. Monday, March 15, 2010 6 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7
JPEG Compression Standard  … 12 Monday, March 15, 2010 7 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
JPEG Compression Standard  … 13 DPCM on DC coffiecients   The DC cofficients are coded separately from  the AC ones. Differential Pulse Code Modulation (DPCM)  is  the coding method.   If the DC cofficients for the 5 image blocks are  150, 155, 149, 152, 144, then the DPCM would produce  150, 5,   -6, 3, -8, assuming  di  DCi +1  − DCi and  d 0= DC 0. Monday, March 15, 2010 8 WILPD, B.I.T.S., PILANI EA ZC473 Multimedia Computing On-Line Lecture-7
JPEG Compression Standard  … 14 Entropy Coding   The DC and AC cofficients usually undergo an entropy  coding step to gain a possible further compression.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 31

7 - OnlineLecture7 LearningObjectives DataCompression...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online