Video Compression Lecture # 5 6 Shahab Baqai LUMS Outline Image - PowerPoint PPT Presentation

CS 584 / CMPE 584 Multimedia Communication Video Compression Lecture # 5 – 6 Shahab Baqai LUMS

Outline Image compression – Transform, uniform quantization, Huffman coding � Video compression – Exploit temporal dimension of video signal – Motion-compensated prediction – Generic (MPEG-type) video coder/decoder architecture 2

3 Video Compression

4 Temporal Processing

5 Video Compression

6 Temporal Processing

Temporal Processing: Motion Estimation 7

Block-Matching Motion Estimation 8

Block Matching: Determining the Best Matching Block 9

Example of Fast Search: 3-Step (Log) Search 10

11 Motion Vector Precision?

Practical Half-Pixel Motion Estimation Algorithm 12

Example: MC-Prediction for Two Consecutive Frames 13

Example: MC-Prediction for Two Consecutive Frames (cont.) 14

Block Matching Algorithm: Summary 15

16 Bi-Directional MC-Prediction

MC-Prediction and Bi-Directional MC-Prediction (P- and B-frames) 17

18 Video Compression

Example Use of I-,P-,B-frames: MPEG Group of Pictures (GOP) 19

Summary of Temporal Processing 20

Basic Video Compression Architecture 21

22 Example Video Encoder

23 Example Video Decoder

24 Blocks & Macro Blocks

Blocks & Macro Blocks (4:2:2) & (4:4:4) Formats 25