Metamerism Art 2014

http://ime.info.hiroshima-cu.ac.jp/

IMECG Laboratory, Hiroshima City University

擬似的な陰影を知覚させる油絵の具の混合

宮崎大輔實重貴文馬場雅志古川亮青山正人日浦慎作


IMECG Lab, Hiroshima City University

Computer-aided art

[Mitra, P

auly 2009]

[Yue, Iw

asaki, Chen,

Dobashi, N

ishita 2012]

[Papas, H

ouit,N

owrouzezahrai,

Gross, Jarosz 2012]

[Mitani 2009]



Metamer sets

Light 1

Light 2

Same

Different

R: 93G: 79B: 94

R: 93G: 79B: 93

R: 81G: 77B: 98

R: 99G: 82B: 101

Introduction(2/5) Perception(3) Mixture(5) Method(2) Experiment(8)



Metameric art

Art [Valluzzi 2012] Watermark [Bala, Braun, Loce 2009]

Microbiology[Kobayashi, Yamada, Hiraishi, Nakauchi2012]

Projector[Nonoyama,Sakaue, Sato2013]




Shading illusion

Em

boss [Kaw

ai 2005]

Projector [A

mano 2012]




Purpose

Mixedpaint 1

Light 1 Light 2

E1Dw1

Mixedpaint 2

Mixedpaint 4

Mixedpaint 3

E1Dw2

E1Dw3

E1Dw4

E1 E2

E2Dw1

E2Dw2

E2Dw3

E2Dw4




Light ObjectSpectral responseCIE-XYZ value

Human perception

400nm

800nm

Introduction(5) Perception(1/3) Mixture(5) Method(2) Experiment(8)



Spectral distribution: same color

Color matching func.(CIE-XYZ)

Light 1 Paint 1

Paint 2

X: 0.36Y: 0.50Z: 0.14

X: 0.36Y: 0.50Z: 0.14

Light 1Color matching func.(CIE-XYZ)




Spectral distribution: different color

Color matching func.(CIE-XYZ)

Light 2 Paint 1

Paint 2

X: 0.35Y: 0.48Z: 0.17

X: 0.38Y: 0.46Z: 0.16

Light 2Color matching func.(CIE-XYZ)




Mixing paints

Paint database D Mixing ratio w

Automaticallydetermine

Introduction(5) Perception(3) Mixture(1/5) Method(2) Experiment(8)



Linear model of mixing paints

[Finlayson, Morovic 2005] [Alsam, Finlayson 2007] [Miyazaki, Nakamura, Baba, Furukawa, Aoyama, Hiura, Asada 2012]

pp NN dwdwdws 2211

d: spectral reflectancew: mixing weight

0.10 0.20 0.30 0.40

(Additive color mixture)




Exponential model of mixing paints

pN

p

w

Nww ddds 2121

pp

pN

p NN

w

Nww dwdwdwddds logloglogexp 221121

21

[Miyazaki, Takahashi, Baba, Aoki, Furukawa, Aoyama, Hiura 2013]

(Linear model in logarithmic space)

d: spectral reflectancew: mixing weight

0.10 0.20 0.30 0.40

(Subtractive color mixture)




Spectral radiance of mixed paint

400 800Wavelength [nm]

Spectral radiance [arb. unit]

[W/sr/m

2/nm w

ith unknown scale]

140

0

B5:M0

B4:M1

B3:M2

B2:M3

B1:M4

B0:M5




Nonlinear dependence of reflectance

Mixture of two paints

Spectral radiance [arb. unit][W

/sr/m2/nm

with unknow

n scale]

0

20

40

60

80

100

120

0 20 40 60 80 100 Light magenta [%]

100 80 60 40 20 0 Horizon blue [%]

Actual data

Linear model

Our model




Emitted light

Photoreceptor

Oil paintdatabase

Mixing weight

E

P

w1w2

w3 wNp

d11

d21

dNb1

w

D

d12

d22

dNb2

d13

d23

dNb3dNbNp

d1Np

d2Np

fL: XYZ ® L*

Lightness

L*

Overview of the phenomena

Introduction(5) Perception(3) Mixture(5) Method(1/2) Experiment(8)



Cost function

Mixedpaint 1

Light 1 Light 2

E1Dw1

Mixedpaint 2

Mixedpaint 4

Mixedpaint 3

E1Dw2

E1Dw3

E1Dw4

E1 E2

E2Dw1

E2Dw2

E2Dw3

E2Dw4

Minimize |fL(PE1Dw1)-fL(PE1Dw2)|




Minimize |fL(PE1Dw3)| & |fL(PE1Dw4)|

Maximize |fL(PE1Dw1)| & |fL(PE1Dw2)|

Minimize |fL(PE2Dw2)| & |fL(PE2Dw3)|

Maximize |fL(PE2Dw1)| & |fL(PE2Dw4)|

Introduction(5) Perception(3) Mixture(5) Method(2/2) Experiment(8)



Artificial sunlight

Hyper-spectral camera

Diffuse whitereflectance standard

Oil paints

Experimental equipments

Introduction(5) Perception(3) Mixture(5) Method(2) Experiment(1/8)





2 LEDs




Mixing ratio

Mixedpaint 1

Mixedpaint 2

Mixedpaint 4

Mixedpaint 3

TRANSPARENT RED

AUREOLIN CADMIUM ORANGE GOLD OCHERE COBALT GREEN COBALT VIOLET LIGHT COMPOSE GREEN JAUNE BRILLANT No.4

TURQUOISE BLUE PERMANENT WHITE EX VIOLET GREY BRILLIANT PINK MARS YELLOW MANGANESE BLUE NOVA

MINERAL VIOLET MAUVE LIGHT MAGENTA LEMON YELLOW ROSE VIOLET TRANSPARENT BLACK




Result under 2 LEDs

Light 1 Light 2

Mixedpaint 1

Mixedpaint 2

Mixedpaint 4

Mixedpaint 3

Mixedpaint 1

Mixedpaint 2

Mixedpaint 4

Mixedpaint 3




Spectral distribution of 4 paints


Spectral reflectivity [no unit]

0

0.5 Mixed paint 1

Mixed paint 2

Mixed paint 3

Mixed paint 4




Observed spectra of 4 paints under 2 LEDs


Spectral radiance [arb. unit][W

/sr/m2/nm

with unknow

n scale]

0

60 Mixed paint 1 under Light 1

Mixed paint 2 under Light 1










Paints on canvas

Light 1 Light 2



IMECG Laboratory, Hiroshima City University

Daisuke Miyazaki 2014Creative Commons Attribution 4.0

International License.

http://www.cg.info.hiroshima-cu.ac.jp/~miyazaki/宮崎大輔 , 實重貴文 , 馬場雅志 , 古川亮 , 青山正人 , 日浦慎作 , “擬似的な陰影を知覚させる油絵の具の混合 ,” 情報処理学会コンピュータビジョンとイメージメディア研究会 ,

2014.11

Science

Metamerism Art 2014