Human Color Vision and Colorimetryvision-lab.tp.chiba-u.jp/~yaguchi/Jpac13_2.pdfWyszecki (1973)" •...
Transcript of Human Color Vision and Colorimetryvision-lab.tp.chiba-u.jp/~yaguchi/Jpac13_2.pdfWyszecki (1973)" •...
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Human Color Vision and Colorimetry "
Hirohisa Yaguchi!Graduate School of Advanced Integration Science!
Chiba University!
Contents"
• Human color vision model"• CIE colorimetry"• Advanced colorimetry"
Additive and Subtractive Color mixture!
Billmeyer and Saltzman's principles of color technology, Roy S. Berns.
Additive and Subtractive Color Mixture �
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Blue Green Red
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Color Reproduction!
TV(CRT, LCD, etc.)"(additive color mixture)"
Printing"(subtractive color mixture)"
Human visual information processing �
• Eye balls: Camera!• Retina:High intelligent input
device!– Photo-sensitive sensor (rods and
cones)"– Luminance channel and chromatic
channel (horizontal cells)"– Contrast (ganglion cells) �
• LGN:M-path; where?� P-path; what?!
– Place, motion, depth, shape, color, texture, detail!
• Visual cortex!– Parietal stream!– Inferotemporal steam!
RetinaEye
Optic nerve
Optic Chiasm
Optic tract
Lateral Geniculatenucleus
Optic radiationPrimaryvisual cortex
Cone mosaic�Joseph Carroll, Daniel C. Gray, Austin Roorda and David R. Williams, Optics & Photonics News, vol. 16, 36-41 (2005)�
Spectral sensitivity of cone �
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Electrophysiological Recordings from Single Cone of the Carp Retina"
Electrophysiological Recordings from Horizontal Cells of Carp Retina"
Opponent-color Stage (Luminance and Color)"
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Hering’s Color Circle"g
by yellow
green
blue
red
r
Receptive field of retinal ganglion cells"
Color opponent cell of the retinal ganglion cell! Double Opponent Color �
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Color Contrast�
http://www.psy.ritsumei.ac.jp/~akitaoka/LorealWS2005.html
Color Assimilation�
http://www.psy.ritsumei.ac.jp/~akitaoka/LorealWS2005.html
Color contrast and color assimilation
http://www.psy.ritsumei.ac.jp/~akitaoka/LorealWS2005.html
Spectral Selectivity of the V4 Cells in the Visual Cortex!
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Color Vision Model"
L M S
achromatic r/g y/b
COLOR APPEARANCE
Luminance ch. Opponent-color channel
Cone Stage
Neural Coding Stage
Striate Cortex Stage
Basic Colorimetry Wyszecki (1973)"
• Colorimetry is a tool used to making a prediction on whether two lights of different spectral power distributions will match in color for certain given conditions of observation. The prediction is made by determining the tristimulus values of the two visual stimuli. If the tristimulus values of a stimulus are identical to those of the other stimulus, a color match will be observed by an average observer with normal color vision.!
Basic colorimetric system�
• LMS (Physiological system)�• RGB (Physical system)�• XYZ (Mathematical system)�
Color Matching and Tristimulus Value �
R
G
B
L
M
S
X
Z
Y C GR
B
Color matching
Light Cones Tristimulus value
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LMS (Physiological colorimetry) �
RGB (Physical colorimetry)�
XYZ (Mathematical colorimetry)�
CIE1931 (x, y) chromaticity diagram �
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We do not see the light but the object!
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Advanced Colorimetry Wyszecki (1973)"
• Colorimetry is its broader sense includes methods of assessing the appearance of color stimuli presented to the observer in complicated surroundings as they may in occur in everyday life. This is considered the ultimate goal of colorimetry, but because of its enormous complexity, this goal is far from being reached.!
Advanced colorimetric system"
• Uniform color space, CIE1976L*a*b*�• Color appearance model, CIECAM02"
CIELAB(CIE1976L*a*b*)"• Color adaptation!
– White is always white!
• Non-linearity!– Physical unit to
psychological l unit!• Color opponency!
– Luminance and chromaticness!
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CIELAB Color Space �CIE Color Appearance Model
(CIECAM02)"
C I E C A M 0 2
I N P U T
L u m i n a n c e o f a d a p t i n g f i e l d
T r i s t i m u l u s v a l u e s o f s a m p l e
T r i s t i m u l u s v a l u e s o f w h i t e
P a r a m e t e r s f o r v i e w i n g c o n d i t i o n
L A
X , Y , Z
X w , Y w , Z w
O U T P U T
H u e , h L i g h t n e s s , J
B r i g h t n e s s , Q S a t u r a t i o n , s C h r o m a , C C o l o r f u l n e s s , M
Human color vision and advance of colorimetry �
リレーションシップ ID rId3 のイメージ パーツが
リレーションシップ ID rId4 のイメージ パーツが
L M S
achromatic r / g y / b
COLOR APPEARANCE
Luminance ch. Opponent-color channel
Cone Stage
Neural Coding Stage
Striate Cortex Stage
リレーションシップ ID rId5 のイメージ パーツが
C I E X Y Z ( 1 9 3 1 )
C I E L A B ( 1 9 7 6 )
C I E C A M02 ( 2 0 0 2 )
Labo Tour for JPAC July 29 (Mon), 2013 12:50-14:25 at Yaguchi-Mizokami Labo SHIZEN-2, 3F, tel:3473
, SHIZEN-2