1

OutlineOutline

Introduction to JEPG2000Introduction to JEPG2000 Why another image compression Why another image compression techniquetechnique FeaturesFeatures

Discrete Wavelet TransformDiscrete Wavelet TransformWavelet transformWavelet transform Wavelet implementationWavelet implementation 5/3 lifting-based wavelet transform5/3 lifting-based wavelet transform Extension algorithmExtension algorithm

2

Why New Encoder?Why New Encoder?

Low bit-rate compression Lossless and lossy compression in

one encoder Large image support Transmission in noisy

environments Non-natural image support

Computer generated image Compound documents Medical Images

3

Features of JPEG2000 (1)Features of JPEG2000 (1)

Very low bit-rate compressionVery low bit-rate compression Lossy and lossless in one algorithmLossy and lossless in one algorithm Progressive transmissionProgressive transmission

Quality, Resolution, ComponentQuality, Resolution, Component

Error resilientError resilient Large imagesLarge images

JPEG at 0.125 bpp(192:1)

JPEG2000 at 0.125 bpp(192:1)

4

Features of JPEG2000 (2)Features of JPEG2000 (2)

ROI: ROI: RRegion egion OOf f IInterestnterest Random code-stream access and Random code-stream access and

processprocess

5

Encoder StructureEncoder Structure

QuantizationWavelet

TransformComponentTransform

Bit ModelingArithmetic

CodingData Ordering

Bit Allocation(Rate Control)

6

Wavelet Transform over an Wavelet Transform over an Image InputImage Input

7

Wavelet ImplementationWavelet Implementation

Convolution Based: Convolution Based: Area and time consumingArea and time consuming ComplicatedComplicated

Lifting Scheme: Lifting Scheme: Reduced memory requiredReduced memory required Lower computational complexityLower computational complexity

8

Wavelet Transform in Wavelet Transform in JPEG2000JPEG2000

5/3 Transform: reversible5/3 Transform: reversible Integer to Integer transformInteger to Integer transform Can be used both for lossless or lossy Can be used both for lossless or lossy

codingcodingi0 i1 i2 i3 i4

h h

l

i0 i1 i2 i3 i4 i5 i6 i7 i9

hh

l

9/7 Transform: nonreversible9/7 Transform: nonreversible Real to Real transformReal to Real transform Can only be used for lossy codingCan only be used for lossy coding

9

Proposed Architecture Proposed Architecture Data PathData Path

VerticalFunctional

Unit

Input 1

Input 2

Input 3

High 1

High 2

High

Low

Memory 1, )Input 1(

Memory 2, )Input 2(

Memory 3, )High 1(

1

2

3

4

Mem 1_out

Input

Mem 1_out

Input

Input

Input

High High

High

Mem 3_out

Mem 3_out

RegH1

RegH2 Horizontal

FunctionalUnit #1

High Buff 1

High Buff 2

Input 1

Input 2

Input 3

HH 1

HH 2

1

2

3

4

HH

LH

HH

HH Buff 1

HH

High

High

Reg

HH1

High Buff 1

HH Buff 1

HH

RegL1

RegL2 Horizontal

FunctionalUnit #2

Low Buff 1

Low Buff 2

Input 1

Input 2

Input 3

HL 1

HL 2

1

2

3

4

HL

LL

HL

HL Buff 1

HL

Low

Low

Reg

HL1

Low Buff 1

HL Buff 1

HL

10

(5,3) Lifting Diagram(5,3) Lifting Diagram

Details

approximate

1/2

1/4

Y3

X3 X4 X5 X6 X7X2

Y7Y5

X8X1X0

Y1

Y2 Y4 Y6

11

Extension AlgorithmExtension Algorithm

Applying the filter to the Applying the filter to the extremes of a streamextremes of a stream

Simple yet area and time Simple yet area and time consumingconsuming

Proposed ideaProposed idea

xx00 xx11 xx22 xx33 xx44 xx55 xx66

xx22 xx11 xx00 xx11 xx22 xx33 xx44 xx55 xx66 xx55 xx44

8-bit register

8-bit register

8-bit register

1 bitshifter

8-bit register

8-bit register

8-bit register

2 bitshifter

8-bit register

8-bit register

HighSample

SequentialInput

8-bit adder8-bit adder#1

8-bit subtractor#2

8-bit adder8-bit adder#3

8-bit adder8-bit adder#4

8-bit register

LowSample