wavelets and multiresolution processing multiple …agotchev/dipii/presentation1.pdfwavelets and...

42
Digital Image Processing, 2nd ed. Digital Image Processing, 2nd ed. www.imageprocessingbook.com © 2002 R. C. Gonzalez & R. E. Woods Wavelets and Multiresolution Processing • Preview – Good old Fourier transform A transform where the basis functions are sinusoids, hence localized in frequency but not localized in time; in transform domain the temporal information is lost – New basis functions called wavelets Varying frequency and limited duration; an attempt to reveal both the frequency and temporal information in the transform domain – Multiresolution analysis Signal (image) representation at multiple resolutions

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Page 1: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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ital I

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ed.

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© 2

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R. C

. Gon

zale

z &

R. E

. Woo

dsWav

elet

s and

Mul

tires

olut

ion

Proc

essi

ng•

Prev

iew

–G

ood

old

Four

ier t

rans

form

•A

tran

sfor

m w

here

the

basi

s fun

ctio

ns a

re si

nuso

ids,

henc

e lo

caliz

ed in

freq

uenc

y bu

t not

loca

lized

in ti

me;

in

tran

sfor

m d

omai

n th

e te

mpo

ral i

nfor

mat

ion

is lo

st–

New

bas

is fu

nctio

ns c

alle

d w

avel

ets

•Va

ryin

gfr

eque

ncy

and

limite

d du

ratio

n; a

n at

tem

pt to

re

veal

bot

h th

e fr

eque

ncy

and

tem

pora

l inf

orm

atio

n in

th

e tra

nsfo

rm d

omai

n–

Mul

tires

olut

ion

anal

ysis

•Si

gnal

(im

age)

repr

esen

tatio

n at

mul

tiple

reso

lutio

ns

Page 2: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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ital I

mag

e Pro

cess

ing,

2nd

ed.

Dig

ital I

mag

e Pro

cess

ing,

2nd

ed.

www.imageprocessingbook.com

© 2

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R. C

. Gon

zale

z &

R. E

. Woo

ds

Bac

kgro

und

•Im

ages

Con

nect

ed re

gion

s of s

imila

r tex

ture

com

bine

d to

form

di

ffer

ent o

bjec

ts•

Smal

l siz

ed o

r low

in c

ontra

st o

bjec

ts: e

xam

ined

at h

igh

reso

lutio

n •

Larg

e si

zed

or h

igh

in c

ontra

st: e

xam

ined

at a

coa

rse

view

•Se

vera

l res

olut

ions

nee

ded

to d

istin

guis

hed

betw

een

diff

eren

t ob

ject

s

–M

athe

mat

ical

ly im

ages

are

2-D

arr

ays o

f int

ensi

ty v

alue

s of

loca

lly v

aryi

ng st

atis

tics (

resu

lting

from

edg

es,

hom

ogen

ous r

egio

ns, e

tc. –

see

Fig.

7.1

)

Page 3: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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cess

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ed.

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ital I

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cess

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© 2

002

R. C

. Gon

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R. E

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ds

His

togr

ams c

ompu

ted

in lo

cal s

quar

esH

isto

gram

s com

pute

d in

loca

l squ

ares

Page 4: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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cess

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ed.

Dig

ital I

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e Pro

cess

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2nd

ed.

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© 2

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R. C

. Gon

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R. E

. Woo

ds

Imag

e Py

ram

ids

Imag

e Py

ram

ids

•Cre

atio

n by

iter

ated

app

roxi

mat

ions

and

inte

rpol

atio

ns (p

redi

ctio

ns)

•The

app

roxi

mat

ion

outp

ut is

take

n as

the

inpu

t for

the

next

reso

lutio

n le

vel

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a n

umbe

r of l

evel

s P, t

wo

pyra

mid

s: a

ppro

xim

atio

n (G

auss

ian)

and

pr

edic

tion

resi

dual

(Lap

laci

an),

are

crea

ted

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roxi

mat

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filte

rs c

ould

be:

•ave

ragi

ng

•low

-pas

s (G

auss

ian)

010

2030

4050

0

10

20

30

40

50

012345678

Page 5: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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cess

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e Pro

cess

ing,

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ed.

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© 2

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R. C

. Gon

zale

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R. E

. Woo

ds

Gau

ssia

n a

nd L

apla

cian

Pyra

mid

sG

auss

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nd L

apla

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Pyra

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J

J –

1J –

2J –

3

Star

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2×51

2;

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Diff

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prop

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for

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age

obje

cts (

win

dow

, va

se, f

low

er, e

tc.)

Page 6: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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© 2

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R. C

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zale

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R. E

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ds

Subban

dCodin

gSubban

dCodin

g

•The

imag

e is

dec

ompo

sed

into

a se

t of b

and-

limite

d co

mpo

nent

s (su

bban

ds).

•Tw

o-ch

anne

l, pe

rfec

t rec

onst

ruct

ion

syst

em; t

wo

sets

of h

alf-

band

filte

rs

•Ana

lysi

s: h

0–

low

-pas

s and

h1

–hi

gh-p

ass a

nd S

ynth

esis

: g0

–lo

w-p

ass a

nd g

1–

high

-pa

ss

Page 7: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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ds

Brief

rem

inder

of

z-tr

ansf

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pro

per

ties

Brief

rem

inder

of

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pro

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pled

and

upsa

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edby

a fa

ctor

of t

wo

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ence

s in

z-do

mai

n

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)(

,....

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2

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Page 8: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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. Gon

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Subban

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(z))

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Page 9: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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ital I

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www.imageprocessingbook.com

© 2

002

R. C

. Gon

zale

z &

R. E

. Woo

ds

Subban

dCodin

gSubban

dCodin

g

}1,0{,

),(

)(

)2(

),(

:co

nditi

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e

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rictiv

M

ore

}1,0{,

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)(

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( ;0

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),(

);(

)2(

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Page 10: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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ital I

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www.imageprocessingbook.com

© 2

002

R. C

. Gon

zale

z &

R. E

. Woo

ds

Fam

ilies

of

hal

f-ban

d P

R f

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g

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Page 11: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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www.imageprocessingbook.com

© 2

002

R. C

. Gon

zale

z &

R. E

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ds

Sep

arab

le f

ilter

ing in 2

-D (

imag

es)

Sep

arab

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-D (

imag

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•Ver

tical

follo

wed

by

horiz

onta

l filt

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r out

put s

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•app

roxi

mat

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and

ver

tical

, hor

izon

tal,

and

diag

onal

det

ail

subb

ands

Page 12: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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ital I

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www.imageprocessingbook.com

© 2

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R. C

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Exa

mple

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igned

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Page 13: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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cess

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© 2

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. Gon

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z &

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Exa

mple

: fo

ur

ban

d s

ubban

dfilter

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of

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age

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the

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the

reco

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Page 14: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 27: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 34: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 35: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 36: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 37: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 38: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 39: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 40: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 41: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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Page 42: Wavelets and Multiresolution Processing multiple …agotchev/DIPII/presentation1.pdfWavelets and Multiresolution Processing •Pr ev ie w – G ood old Fourier transform • A transform

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