scalable and robust video encoding for real-time communication

Scalable and Robust Video Encoding for Real-time

Communication

Samah A. SenbelAdvisorAdvisor: Dr. Hussein Abdel

Wahab

Outline Introduction & Motivation Background A new Image Encoding Technique Quadtree-based Video Encoding Technique Octree-based Video Encoding Technique Differential Octree-based Video Encoding

Technique Experimental results

Introduction & Motivation

The Requirements for a real-time encoding technique are :

Good Compression Ratio Simplicity Scalability Robustness Ease of decoding

Introduction & Motivation

We developed these 4 Encoders: Quadtree-based Image Encoder Differential Quadtree-based Video

Encoder Octree-based Video Encoder Differential Octree-based Video Encoder

Scalability

Why do we need Scalability?

Heterogeneous Receivers Low-bandwidth communication

• Distant Learning• Mobile hosts

Dealing with network traffic Better error control

Background (Quadtree)

Vector Quantization

Overview of the Image Encoding Technique

Step 1: Mean removal

Step 2: Generate Quadtree

level Structure4 13 10112 1000 0011 00111 1000 1010 0000 1000 01000 0000 0000 0000 0000 0000

Step 3: Vector Quantization

The Quadtree data is then COMPRESSED using vector quantization

Each level is encoded independently to reflect its importance.

Decoding Technique

Perform reverse vector quantization (table look up)

Convert from Quadtree to array Add the means image

Experimental results

RobustnessLoss PSNR

New Tech.PSNRShusterman Tech.

0 % 32.35 dB 32.35 dB5 % 31.62 dB 27.86 dB10 % 31.17 dB 27.84 dB20 % 27.27 dB 25.14 dB40 % 23.86 dB 20.46 dB

Experimental Results

Robustness at 20 % loss

Differential Quadtree Encoding Technique

Test Videos

Compression results

Scalability

Robustness

Loss PSNRQuadtree

PSNRMPEG-2

0 % 32.69 dB 32.70 dB5 % 32.03 dB 30.67 dB10 % 31.17 dB 28.14 dB20 % 27.27 dB 23.07 dB40 % 23.86 dB 18.47 dB

Octree

The Octree Video Encoding Technique

Encoding Technique

Compression(1)

MissA Encoded at 16 Kbps

Compression(2)

Football Encoded at 16 Kbps

Robustness

Loss PSNROctree

PSNRQuadtree

PSNRMPEG-2

0 % 32.70 dB 32.69 dB 32.70 dB5 % 32.47 dB 32.03 dB 30.67 dB10 % 32.07 dB 31.17 dB 28.14 dB20 % 30.91 dB 27.27 dB 23.07 dB40 % 28.62 dB 23.86 dB 18.47 dB

Differential Octree Encoding Technique

Summary

Main Objective:Design a Video Encoder with these

properties:• Good Compression• Scalability• Robustness• Ease of Decoding

Summary

We developed these 4 Encoders: Quadtree-based Image Encoder Differential Quadtree-based Video

Encoder Octree-based Video Encoder Differential Octree-based Video Encoder