photorealistic scene reconstruction by voxel , 1999, pp...

51
Multiview stereo CMU’s 3D Room Readings (Optional) S. M. Seitz and C. R. Dyer, Photorealistic Scene Reconstruction by Voxel Coloring , International Journal of Computer Vision, 35(2), 1999, pp. 151-173.

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Mul

tivie

wst

ereo C

MU

’s 3

D R

oom

Rea

ding

s (O

ptio

nal)

•S

. M. S

eitz

and

C. R

. Dye

r, P

hoto

real

istic

Sce

ne R

econ

stru

ctio

n by

Vox

el

Col

orin

g, In

tern

atio

nal J

ourn

al o

f Com

pute

r Vis

ion,

35(

2), 1

999,

pp.

151

-173

.

Cho

osin

g th

e B

asel

ine

wid

th o

f a

pixe

l

all o

f the

sepo

ints

pro

ject

to th

e sa

me

pair

of p

ixel

s

Wha

t’s th

e op

timal

bas

elin

e?•

Too

smal

l: la

rge

dept

h er

ror

•To

o la

rge:

diff

icul

t sea

rch

prob

lem

Larg

e B

asel

ine

Larg

e B

asel

ine

Smal

l Bas

elin

eSm

all B

asel

ine

The

Effe

ct o

f Bas

elin

e on

Dep

th E

stim

atio

n

Mul

tibas

elin

eS

tere

o

Bas

ic A

ppro

ach

•C

hoos

e a

refe

renc

e vi

ew•

Use

you

r fav

orite

ste

reo

algo

rithm

BU

T>

repl

ace

two-

view

SS

D w

ith S

SD

ove

r all

base

lines

Lim

itatio

ns•

Mus

t cho

ose

a re

fere

nce

view

(bad

)•

Vis

ibili

ty!

The

glob

al v

isib

ility

prob

lem

Whi

ch p

oint

s ar

e vi

sibl

e in

whi

ch im

ages

?

Know

n Sc

ene

Know

n Sc

ene

Forw

ard

Vis

ibili

tykn

own

scen

eIn

vers

e V

isib

ility

know

n im

ages

Unk

now

n Sc

ene

Unk

now

n Sc

ene

Vol

umet

ric s

tere

o

Scen

e Vo

lum

eSc

ene

Volu

me

VV Inpu

t Im

ages

Inpu

t Im

ages

(Cal

ibra

ted)

(Cal

ibra

ted)

Goa

l:

Goa

l: D

eter

min

e oc

cupa

ncy,

“co

lor”

of p

oint

s in

VD

eter

min

e oc

cupa

ncy,

“co

lor”

of p

oint

s in

V

Dis

cret

e fo

rmul

atio

n: V

oxel

Col

orin

g

Dis

cret

ized

D

iscr

etiz

ed

Scen

e Vo

lum

eSc

ene

Volu

me

Inpu

t Im

ages

Inpu

t Im

ages

(Cal

ibra

ted)

(Cal

ibra

ted)

Goa

l: A

ssig

n R

GB

A v

alue

s to

vox

els

in V

phot

o-co

nsis

tent

with

imag

es

Com

plex

ity a

nd c

ompu

tabi

lity

Dis

cret

ized

D

iscr

etiz

ed

Scen

e Vo

lum

eSc

ene

Volu

me

N

voxe

lsN

vo

xels

C

colo

rsC

co

lors

33

All S

cene

s (C

N3 )

Phot

o-Co

nsis

tent

Scen

es

True

Scen

e

Issu

es

Theo

retic

al Q

uest

ions

•Id

entif

y cl

ass

of a

llph

oto-

cons

iste

nt s

cene

s

Pra

ctic

al Q

uest

ions

•H

ow d

o w

e co

mpu

te p

hoto

-con

sist

ent m

odel

s?

Vox

el c

olor

ing

solu

tions

1. C

=2 (s

hape

from

silh

ouet

tes)

•V

olum

e in

ters

ectio

n [B

aum

gart

1974

]>

For m

ore

info

: R

apid

octre

eco

nstru

ctio

n fro

m im

age

sequ

ence

s.R

.Sze

liski

, C

VGIP

: Im

age

Und

erst

andi

ng, 5

8(1)

:23-

32, J

uly

1993

. (th

is p

aper

is a

ppar

ently

no

t ava

ilabl

e on

line)

2. C

unc

onst

rain

ed, v

iew

poin

t con

stra

ints

•V

oxel

col

orin

g al

gorit

hm [S

eitz

& D

yer 9

7]

3. G

ener

al C

ase

•S

pace

car

ving

[Kut

ulak

os &

Sei

tz 9

8]

Rec

onst

ruct

ion

from

Silh

ouet

tes

(C =

2)

Bina

ry I

mag

esBi

nary

Im

ages

App

roac

h:

•P

roje

ctea

ch s

ilhou

ette

•In

ters

ect p

roje

cted

vol

umes

Vol

ume

inte

rsec

tion

Rec

onst

ruct

ion

Con

tain

s th

e Tr

ue S

cene

•In

the

limit

(all

view

s) g

et v

isua

l hul

l>

Com

plem

ent o

f all

lines

that

don

’t in

ters

ect S

Vox

el a

lgor

ithm

for v

olum

e in

ters

ectio

n

Col

or v

oxel

bla

ck if

on

silh

ouet

te in

eve

ry im

age

•fo

r M im

ages

, N3

voxe

ls•

Don

’t ha

ve to

sea

rch

2N3

poss

ible

sce

nes!

O(M

N3 )

,

Pro

perti

es o

f Vol

ume

Inte

rsec

tion

Pro

s •E

asy

to im

plem

ent,

fast

•A

ccel

erat

ed v

ia o

ctre

es[S

zelis

ki19

93]

Con

s •N

o co

ncav

ities

•R

econ

stru

ctio

n is

not

pho

to-c

onsi

sten

t•

Req

uire

s id

entif

icat

ion

of s

ilhou

ette

s

Vox

el C

olor

ing

Sol

utio

ns

1. C

=2 (s

ilhou

ette

s)•

Vol

ume

inte

rsec

tion

[Bau

mga

rt19

74]

2. C

unc

onst

rain

ed, v

iew

poin

t con

stra

ints

•V

oxel

col

orin

g al

gorit

hm [S

eitz

& D

yer 9

7]>

For m

ore

info

: ht

tp://

ww

w.c

s.w

ashi

ngto

n.ed

u/ho

mes

/sei

tz/p

aper

s/ijc

v99.

pdf

3. G

ener

al C

ase

•S

pace

car

ving

[Kut

ulak

os &

Sei

tz 9

8]

Vox

el C

olor

ing

App

roac

h

1.

Ch

oose

vox

el1

. C

hoo

se v

oxel

2.

Pro

ject

an

d co

rrel

ate

2.

Pro

ject

an

d co

rrel

ate

3.

3.

Col

or if

con

sist

ent

Col

or if

con

sist

ent

(sta

ndar

d de

viat

ion

of p

ixel

co

lors

bel

ow th

resh

old)

Vis

ibili

ty P

robl

em:

Vis

ibili

ty P

robl

em:

in w

hich

imag

es is

eac

h vo

xel v

isib

le?

in w

hich

imag

es is

eac

h vo

xel v

isib

le?

Dep

th O

rder

ing:

vis

it oc

clud

ers

first

!

Laye

rsLa

yers

Scen

eSc

ene

Trav

ersa

lTr

aver

sal

Con

ditio

n:

Con

ditio

n: d

epth

ord

er is

the

dept

h or

der i

s th

e sa

me

for a

ll in

put v

iew

ssa

me

for a

ll in

put v

iew

s

Pan

oram

ic D

epth

Ord

erin

g

•C

amer

as o

rient

ed in

man

y di

ffere

nt d

irect

ions

•P

lana

r dep

th o

rder

ing

does

not

app

ly

Pan

oram

ic D

epth

Ord

erin

g

Lay

ers r

adia

te o

utw

ards

from

cam

eras

Lay

ers r

adia

te o

utw

ards

from

cam

eras

Pan

oram

ic L

ayer

ing

Lay

ers r

adia

te o

utw

ards

from

cam

eras

Lay

ers r

adia

te o

utw

ards

from

cam

eras

Pan

oram

ic L

ayer

ing

Lay

ers r

adia

te o

utw

ards

from

cam

eras

Lay

ers r

adia

te o

utw

ards

from

cam

eras

Com

patib

le C

amer

a C

onfig

urat

ions

Dep

th-O

rder

Con

stra

int

•S

cene

out

side

con

vex

hull

of c

amer

a ce

nter

s

Out

war

d-Lo

okin

gC

amer

a in

side

sce

neIn

war

d-Lo

okin

gC

amer

a ab

ove

scen

eca

mer

as a

bove

sce

neca

mer

as in

side

sce

ne

Cal

ibra

ted

Imag

e A

cqui

sitio

n

Sele

cted

Din

osau

r Im

ages

Sele

cted

Din

osau

r Im

ages

Cal

ibra

ted

Turn

tabl

e36

0° ro

tatio

n (2

1 im

ages

)

Sele

cted

Flo

wer

Imag

esSe

lect

ed F

low

er Im

ages

Vox

el C

olor

ing

Res

ults

(Vid

eo)

Din

osau

r R

econ

stru

ctio

nD

inos

aur

Rec

onst

ruct

ion

72

K v

oxel

s co

lore

d7

2 K

vox

els

colo

red

7.6

M v

oxel

s te

sted

7.6

M v

oxel

s te

sted

7 m

in. t

o co

mpu

te

7 m

in. t

o co

mpu

te

on a

25

0M

Hz

SGI

Flow

er R

econ

stru

ctio

nFl

ower

Rec

onst

ruct

ion

70

K v

oxel

s co

lore

d7

0 K

vox

els

colo

red

7.6

M v

oxel

s te

sted

7.6

M v

oxel

s te

sted

7 m

in. t

o co

mpu

te

7 m

in. t

o co

mpu

te

on a

25

0M

Hz

SGI

on a

25

0M

Hz

SGI

on a

25

0M

Hz

SGI

Lim

itatio

ns o

f Dep

th O

rder

ing

A v

iew

-inde

pend

ent d

epth

ord

er m

ay n

ot e

xist

pq

Nee

d m

ore

pow

erfu

l gen

eral

-cas

e al

gorit

hms

•U

ncon

stra

ined

cam

era

posi

tions

•U

ncon

stra

ined

sce

ne g

eom

etry

/topo

logy

Vox

el C

olor

ing

Sol

utio

ns

1. C

=2 (s

ilhou

ette

s)•

Vol

ume

inte

rsec

tion

[Bau

mga

rt19

74]

2. C

unc

onst

rain

ed, v

iew

poin

t con

stra

ints

•V

oxel

col

orin

g al

gorit

hm [S

eitz

& D

yer 9

7]

3. G

ener

al C

ase

•S

pace

car

ving

[Kut

ulak

os &

Sei

tz 9

8]>

For m

ore

info

: ht

tp://

ww

w.c

s.w

ashi

ngto

n.ed

u/ho

mes

/sei

tz/p

aper

s/ku

tu-ij

cv00

.pdf

Spa

ce C

arvi

ng A

lgor

ithm

Spa

ce C

arvi

ng A

lgor

ithm

Imag

e 1

Imag

e N

…...

•In

itial

ize

to a

vol

ume

V c

onta

inin

g th

e tru

e sc

ene

•R

epea

t unt

il co

nver

genc

e

•C

hoos

e a

voxe

l on

the

curre

nt s

urfa

ce

•C

arve

if n

ot p

hoto

-con

sist

ent

•P

roje

ct to

vis

ible

inpu

t im

ages

Con

verg

ence

Con

sist

ency

Pro

perty

•Th

e re

sulti

ng s

hape

is p

hoto

-con

sist

ent

>al

l inc

onsi

sten

t poi

nts

are

rem

oved

Con

verg

ence

Pro

perty

•C

arvi

ng c

onve

rges

to a

non

-em

pty

shap

e>

a po

int o

n th

e tru

e sc

ene

is n

ever

rem

oved

p

Vis

ibili

ty le

mm

a

Let p

be

a po

int o

n V

’s s

urfa

ce, S

urf(V

), an

d le

t Vis

v(p) b

e th

e co

llect

ion

of in

put i

mag

es in

whi

ch V

doe

s no

t occ

lude

p. I

f V’,

a su

bset

of V

, is

a sh

ape

that

als

o ha

s p

on it

s su

rface

, Vis

v(p) i

s a

subs

et o

f Vis

v’(p

).

pV

Vc 2

c 3

c 1

c 4

Non

-pho

to-c

onsi

sten

cy le

mm

a

Let p

, whi

ch is

in S

urf(V

), is

not

pho

to-c

onsi

sten

t with

a s

ubse

t of

Vis

v(p),

it is

not

pho

to-c

onsi

sten

t with

the

entir

e V

isv(p

).

pV

c 2

c 3

c 1

c 4

Whi

ch s

hape

do

you

get?

Tru

e Sc

ene

Tru

e Sc

ene

VV

Phot

o H

ull

Phot

o H

ull

VV

The

Pho

to H

ulli

s th

e U

NIO

N o

f all

phot

o-co

nsis

tent

sce

nes

in V

•It

is a

pho

to-c

onsi

sten

t sce

ne re

cons

truct

ion

•Ti

ghte

st p

ossi

ble

boun

d on

the

true

scen

e

Spa

ce C

arvi

ng A

lgor

ithm

The

Bas

ic A

lgor

ithm

is U

nwie

ldy

•C

ompl

ex u

pdat

e pr

oced

ure

Alte

rnat

ive:

Mul

ti-P

ass

Pla

ne S

wee

p•

Effi

cien

t, ca

n us

e te

xtur

e-m

appi

ng h

ardw

are

•C

onve

rges

qui

ckly

in p

ract

ice

•E

asy

to im

plem

ent

Res

ults

Alg

orith

m

Mul

ti-P

ass

Pla

ne S

wee

p•

Swee

p pl

ane

in e

ach

of 6

prin

cipl

e di

rect

ions

•C

onsi

der c

amer

as o

n on

ly o

ne s

ide

of p

lane

•R

epea

t unt

il co

nver

genc

e

True

Sce

neR

econ

stru

ctio

n

Mul

ti-P

ass

Pla

ne S

wee

p•

Swee

p pl

ane

in e

ach

of 6

prin

cipl

e di

rect

ions

•C

onsi

der c

amer

as o

n on

ly o

ne s

ide

of p

lane

•R

epea

t unt

il co

nver

genc

e

Mul

ti-P

ass

Pla

ne S

wee

p•

Swee

p pl

ane

in e

ach

of 6

prin

cipl

e di

rect

ions

•C

onsi

der c

amer

as o

n on

ly o

ne s

ide

of p

lane

•R

epea

t unt

il co

nver

genc

e

Mul

ti-P

ass

Pla

ne S

wee

p•

Swee

p pl

ane

in e

ach

of 6

prin

cipl

e di

rect

ions

•C

onsi

der c

amer

as o

n on

ly o

ne s

ide

of p

lane

•R

epea

t unt

il co

nver

genc

e

Mul

ti-P

ass

Pla

ne S

wee

p•

Swee

p pl

ane

in e

ach

of 6

prin

cipl

e di

rect

ions

•C

onsi

der c

amer

as o

n on

ly o

ne s

ide

of p

lane

•R

epea

t unt

il co

nver

genc

e

Mul

ti-P

ass

Pla

ne S

wee

p•

Swee

p pl

ane

in e

ach

of 6

prin

cipl

e di

rect

ions

•C

onsi

der c

amer

as o

n on

ly o

ne s

ide

of p

lane

•R

epea

t unt

il co

nver

genc

e

Spa

ce C

arvi

ng R

esul

ts:

Afri

can

Vio

let

Inpu

t Im

age

(1 o

f 4

5)

Rec

onst

ruct

ion

Rec

onst

ruct

ion

Rec

onst

ruct

ion

Spa

ce C

arvi

ng R

esul

ts:

Han

d

Inpu

t Im

age

(1 o

f 1

00

)

Vie

ws

of R

econ

stru

ctio

n

Hou

se W

alkt

hrou

gh

24 re

nder

ed in

put v

iew

s fro

m in

side

and

outs

ide

Spa

ce C

arvi

ng R

esul

ts:

Hou

se

Inpu

t Im

age

Inpu

t Im

age

(tru

e sc

ene)

Rec

onst

ruct

ion

Rec

onst

ruct

ion

37

0,0

00

vox

els

(tru

e sc

ene)

37

0,0

00

vox

els

Spa

ce C

arvi

ng R

esul

ts:

Hou

se

Inpu

t Im

age

Inpu

t Im

age

(tru

e sc

ene)

Rec

onst

ruct

ion

Rec

onst

ruct

ion

37

0,0

00

vox

els

(tru

e sc

ene)

37

0,0

00

vox

els

Spa

ce C

arvi

ng R

esul

ts:

Hou

se

New

Vie

w (

tru

e sc

ene)

New

Vie

w (

tru

e sc

ene)

Rec

onst

ruct

ion

Rec

onst

ruct

ion

New

Vie

wN

ew V

iew

(tru

e sc

ene)

(tru

e sc

ene)

Rec

onst

ruct

ion

Rec

onst

ruct

ion

(wit

h n

ew in

put

view

)R

econ

stru

ctio

nR

econ

stru

ctio

n(w

ith

new

inpu

t vi

ew)

Oth

er F

eatu

res

Coa

rse-

to-fi

ne R

econ

stru

ctio

n•

Rep

rese

nt s

cene

as

octre

e•

Rec

onst

ruct

low

-res

mod

el fi

rst,

then

refin

e

Har

dwar

e-A

ccel

erat

ion

•U

se te

xtur

e-m

appi

ng to

com

pute

vox

el p

roje

ctio

ns•

Pro

cess

vox

els

an e

ntire

pla

ne a

t a ti

me

Lim

itatio

ns•

Nee

d to

acq

uire

cal

ibra

ted

imag

es•

Res

trict

ion

to s

impl

e ra

dian

ce m

odel

s•

Bia

s to

war

d m

axim

al (f

at) r

econ

stru

ctio

ns•

Tran

spar

ency

not

sup

porte

d

Oth

er A

ppro

ache

sLe

vel-S

et M

etho

ds [

Faug

eras

& K

eriv

en19

98]

•E

volv

e im

plic

it fu

nctio

n by

sol

ving

PD

E’s

Pro

babi

listic

Vox

el R

econ

stru

ctio

n [D

eBon

et&

Vio

la 1

999]

, [B

road

hurs

tet a

l. 20

01]

•S

olve

for v

oxel

unc

erta

inty

(als

o tra

nspa

renc

y)

Tran

spar

ency

and

Mat

ting

[Sze

liski

& G

olla

nd19

98]

•C

ompu

te v

oxel

s w

ith a

lpha

-cha

nnel

Max

Flo

w/M

in C

ut

[Roy

& C

ox 1

998]

•G

raph

theo

retic

form

ulat

ion

Mes

h-B

ased

Ste

reo

[Fua

& L

ecle

rc19

95],

[Zha

ng &

Sei

tz 2

001]

•M

esh-

base

d bu

t sim

ilar c

onsi

sten

cy fo

rmul

atio

n

Virt

ualiz

ed R

ealit

y [N

aray

an, R

ande

r, K

anad

e 19

98]

•P

erfo

rm s

tere

o 3

imag

es a

t a ti

me,

mer

ge re

sults

Bib

liogr

aphy

Vol

ume

Inte

rsec

tion

•M

artin

& A

ggar

wal

, “V

olum

etric

des

crip

tion

of o

bjec

ts fr

om m

ultip

le v

iew

s”, T

rans

. Pat

tern

A

naly

sis

and

Mac

hine

Inte

lligen

ce,

5(2)

, 199

1, p

p. 1

50-1

58.

•Sz

elis

ki, “

Rap

id O

ctre

eC

onst

ruct

ion

from

Imag

e S

eque

nces

”, C

ompu

ter V

isio

n, G

raph

ics,

an

d Im

age

Pro

cess

ing:

Imag

e U

nder

stan

ding

, 58(

1), 1

993,

pp.

23-

32.

Vox

el C

olor

ing

and

Spa

ce C

arvi

ng•

Seitz

& D

yer,

“Pho

tore

alis

tic S

cene

Rec

onst

ruct

ion

by V

oxel

Col

orin

g”, P

roc.

Com

pute

r Vis

ion

and

Pat

tern

Rec

ogni

tion

(CV

PR

), 19

97, p

p. 1

067-

1073

.•

Seitz

& K

utul

akos

, “P

leno

ptic

Imag

e E

ditin

g”,

Pro

c. In

t. C

onf.

on C

ompu

ter V

isio

n (IC

CV

), 19

98, p

p. 1

7-24

.•

Kutu

lako

s &

Sei

tz, “

A T

heor

y of

Sha

pe b

y S

pace

Car

ving

”, P

roc.

ICC

V, 1

998,

pp.

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.

Bib

liogr

aphy

Rel

ated

Ref

eren

ces

•Bo

lles,

Bak

er, a

nd M

arim

ont,

“Epi

pola

r-P

lane

Imag

e A

naly

sis:

An

App

roac

h to

Det

erm

inin

g S

truct

ure

from

Mot

ion”

, Int

erna

tiona

l Jou

rnal

of C

ompu

ter V

isio

n, v

ol1,

no

1, 1

987,

pp.

7-5

5.•

DeB

onet

& V

iola

, “P

oxel

s: P

roba

bilis

tic V

oxel

ized

Volu

me

Rec

onst

ruct

ion ”

, Pro

c. In

t. C

onf.

on

Com

pute

r Vis

ion

(ICC

V) 1

999.

•Br

oadh

urst

, Dru

mm

ond,

and

Cip

olla

, "A

Pro

babi

listic

Fra

mew

ork

for S

pace

Car

ving

“, In

tern

atio

nal C

onfe

renc

e of

Com

pute

r Vis

ion

(ICC

V), 2

001,

pp.

388

-393

.•

Faug

eras

& K

eriv

en, “

Var

iatio

nalp

rinci

ples

, sur

face

evo

lutio

n, P

DE

's, l

evel

set

met

hods

and

the

ster

eo p

robl

em",

IEE

E T

rans

. on

Imag

e P

roce

ssin

g, 7

(3),

1998

, pp.

336

-344

.•

Szel

iski

& G

olla

nd, “

Ste

reo

Mat

chin

g w

ith T

rans

pare

ncy

and

Mat

ting”

, Pro

c. In

t. C

onf.

on

Com

pute

r Vis

ion

(ICC

V), 1

998,

517

-524

.•

Roy

& C

ox, “

A M

axim

um-F

low

For

mul

atio

n of

the

N-c

amer

a S

tere

o C

orre

spon

denc

e P

robl

em”,

Pro

c. IC

CV

, 199

8, p

p. 4

92-4

99.

•Fu

a &

Lec

lerc

, “O

bjec

t-cen

tere

d su

rface

reco

nstru

ctio

n: C

ombi

ning

mul

ti-im

age

ster

eo a

nd

shad

ing"

, Int

erna

tiona

l Jou

rnal

of C

ompu

ter V

isio

n, 1

6, 1

995,

pp.

35-

56.

•N

aray

anan

, Ran

der,

& K

anad

e, “C

onst

ruct

ing

Virt

ual W

orld

s U

sing

Den

se S

tere

o”, P

roc.

ICC

V,

1998

, pp.

3-1

0.

Sum

mar

y

Thin

gs to

take

aw

ay fr

om th

is le

ctur

e•

Bas

elin

e tra

deof

f•

Mul

tibas

elin

est

ereo

app

roac

h•

Vox

el c

olor

ing

prob

lem

•V

olum

e in

ters

ectio

n al

gorit

hm•

Vox

el c

olor

ing

algo

rithm

•S

pace

car

ving

alg

orith

m