5
(R, G, B)co
mpo
n
en
t =
CC
sRGB
12.92
, if CC
sRGB
≤ 0.03928
(
CC
sRGB
+ 0.055
1.055 )
2.4
, otherwise
co
n
trast =
L
1
+ 0.05
L2
+ 0.05
lu min
an
ce = 0.2126 × R + 0.7152 × G + 0.0722 × B
https://raw.githubusercontent.com/emarley/ColorContrast/master/ColorContrast.pdf
ΠϥϨʹiPhoneͷεΫγϣΛஔͨ͠ΒϠό͍৭ʹͳͬͨॿ͚ͯʂ
ʮiPhone48bppରԠͳΜͩΑʂʯ
▸ When appropriate, use the Display P3 color profile at 16
bits per pixel (per channel) and export images in PNG
format.
29
https://developer.apple.com/design/human-interface-guidelines/ios/visual-design/color/
XYZͷੈքΑ͏ͦ͜ʂ
ࡾܹXYZͱ৭xyʢఆٛVer.ʣ
49
X = K
∫
780
380
S(λ)R(λ)¯
x(λ)dλ
Y = K
∫
780
380
S(λ)R(λ)¯
y(λ)dλ
Z = K
∫
780
380
S(λ)R(λ)¯
z(λ)dλ
ͨͩ͠
∫
780
380
dλ
࠷େࢹײޮՌʢఆʣ
Մࢹޫ380nmʙ780nm
S(λ) ޫݯͷޫ
R(λ) ମͷޫࣹ or ಁա
¯
x(λ), ¯
y(λ), ¯
z(λ) ଌ৭ඪ४؍ଌऀͷ৭ؔ
߹Α͘༻ҙͨ͠ͷܹͰͳ͘ίϨ
K
x =
X
X + Y + Z
y =
Y
X + Y + Z
z =
Z
X + Y + Z
= 1 − x − y
Slide 50
Slide 50 text
XYZͷੈքΑ͏ͦ͜ʂ
৭ۭؒ / color space
▸ σΟεϓϨΠϓϦϯλ͕ѻ͏৭ͷൣғํ๏Λࣔͨ͠ͷ
▸ ݪ৭ / primariesɿݪ৭͕ͦΕͧΕͲͷ৭͔
▸ ৭Ҭ / color gamutɿѻ͑Δ৭ͷൣғͲ͔͜
▸ ΨϯϚ / gamma transfer functionɿ໌Δ͞ʹؔ͢Δௐ۩߹
▸ ͞·͟·ͳن͕֨͋Δ
50
Slide 51
Slide 51 text
XYZͷੈքΑ͏ͦ͜ʂ
ΨϯϚ / gamma transfer function
▸ ৭ʹͲͷ͘Β͍ͷิਖ਼ΛՃ͑Δ͔
▸ ิਖ਼͕ՃΘ͍ͬͯͳ͍৭ઢܗ / linearͱݺΕΔ
▸ ݹ͘ϒϥϯʹΑΔ৭ͷมԽΛमਖ਼͢Δͷ
▸ ਓؒ໌Δ͍৭ΑΓ҉͍৭ͷํͷมԽʹහײ
51
↓
ݟΔڥʹԠͨ͡ิਖ਼ΛՃ͑Δʂ
XYZͷੈքΑ͏ͦ͜ʂ
Display P3৭ۭؒ
▸ Apple͕࡞ͬͨ৭ۭؒͰɺiPhone7Ҏ߱Ͱ༻Մೳ
▸ > This color space uses the DCI P3 primaries, a D65 white
point, and the sRGB transfer function.
▸ ҙ༁ɿ৭ҬDCI P3ͱಉ͡ͰΊɺͰσΟεϓϨΠΛݟΔ
ڥsRGBͱಉ͡ఆʂ
56
https://developer.apple.com/documentation/coregraphics/cgcolorspace/1408916-displayp3
XYZͷੈքΑ͏ͦ͜ʂ
UIColor.initͷઆ໌ΛಡΜͰΈΔ
▸ > On applications linked for iOS 10 or later, the color is
specified in an extended color space, and the input value
is never clamped.
▸ ҙ༁ɿෳͷ৭ۭؒΛಉ࣌ʹѻ͑ΔҎ্ɺຊདྷ͋Γ͑ͳ͍
ΛೖΕͯखΛՃ͑ͣͦͷ··ѻ͏Αɻ
62
https://developer.apple.com/documentation/uikit/uicolor/1621925-init
ίϯτϥετɺײʁ
ͦͦίϯτϥετͬͯʁ
▸ ৭ɾτʔϯɾܗͳͲͷࠩҧͷ͜ͱͰɺࢹ֮ޮՌɺσβΠϯɺ
ΠϝʔδͳͲʹཱͯΒΕΔͷɻࢹ֮తͳಛͷࠩɻ
by Wikipedia
88
https://ja.wikipedia.org/wiki/
%E3%82%B3%E3%83%B3%E3%83%88%E3%83%A9%E3%82%B9%E3%83%88
Slide 89
Slide 89 text
ίϯτϥετɺײʁ
ίϯτϥετײ
▸ ബ͍จࣈɺബ͍ࣶ༷ΛೝࣝͰ͖Δ͔Ͳ͏͔ͷ߹͍
▸ നোͳͲͰԼ͢Δ͜ͱ͕͋Δ
▸ దͳจࣈαΠζίϯτϥετൺʹ͢Δඞཁ͕͋Δ
89
E E E E E E E E E E E
ࢀߟจݙͱ͔
ΠϥϨͱ৭ਂ
▸ ৭ਂͱ - IT༻ޠࣙయ e-Words
▸ RGB Ϗοτਂͷ͏Μͪ͘ (લฤ) ʙ લఏࣝ - Qiita
▸ Why are the colors of certain PNG files getting distorted when opened in Illustrator? - Graphic Design Stack
Exchange
115
Slide 116
Slide 116 text
ࢀߟจݙͱ͔
ΨΠυϥΠϯྨ
▸ Color and Contrast - Accessibility - Human Interface Guidelines - Apple Developer
▸ Color - Visual Design - iOS - Human Interface Guidelines - Apple Developer
▸ Make apps more accessible | Android Developers
▸ Web Content Accessibility Guidelines (WCAG) 2.0
▸ Understanding Success Criterion 1.4.3 | Understanding WCAG 2.0
▸ Accessibility Requirements for People with Low Vision
116
ࢀߟจݙͱ͔
ίϯτϥετ
▸ ίϯτϥετൺͱ - IT༻ޠࣙయ e-Words
▸ ίϯτϥετײݕࠪ – य़Ҫࢢɾখࢢͷ؟ՊͳΒฏా؟Պ
▸ ίϯτϥετײଌఆɾάϨΞݕࠪ | ͖͘ͳ౬ా؟Պ ެࣜαΠτ
▸ Understanding Success Criterion 1.4.3 | Understanding WCAG 2.0
▸ A close look at the sRGB formula
▸ A Standard Default Color Space for the Internet - sRGB
▸ E: Viewing Flare - Digital Color Management - Wiley Online Library
121