chromaticity-color-utilities
Advanced tools
Color utilities for Node.js.
Conversion, modification, and color schemes of: RGB (at any bit depth), HSV, HSL, HSI, CYMK, YIQ, XYZ, xyY, L*a*b*, L*u*v*, Y'PbPr, and Y'CbCr. (More to follow.)
NOT YET PUBLISHED
npm install --save chromaticity-color-utilities
Any color can be converted to any other, with only a few caveats. Construction from(), conversion to(), and modification modify() methods can be chained.
Object properties can be accessed directly, e.g. color.r for the red channel value.
Most colors will retain their arguments as a part of their object properties, such as bitDepth, colorSpace, etc.
const Color = require('chromaticity-color-utilities')
let color1 = Color.from('rgb',[255,128,0]).to('hsv')
// hsv { h: 34, s: 100, v: 88, a: 100 }
let color2 = Color.from('hex','ff3201').to('rec709rgb', { bitRate: 10 })
// rec709rgb { r: 940, g: 298, b: 67, a: 940, bitDepth: 10, max: 1023 }
let color6 = Color.from('hex', 'ff00ff').to('lab',{
colorSpace: 'AdobeRGB',
referenceWhite: 'd50'
})
// lab {
// l: 67.60166164169028,
// a: 101.30709261827131,
// b: -50.813827160707525,
// colorSpace: 'adobergb1998',
// referenceWhite: 'd50'
// }
let color7 = Color.from('hsl',[300,100,50]).to('ypbpr',{kb:0.0722, kr:0.2126})
// ypbpr { y: 0.2848, pb: 0.3854278939426601, pr: 0.45415290830581667 }
let color3 = Color.from('rgb',[255,0,0]).modify('blend', {with: Color.from('rgb',[0,255,0])})
// rgb { r: 128, g: 128, b: 0, a: 255, bitDepth: 8, max: 255 }
let color4 = Color.from('rgb',[255,0,0]).modify('blend', {
with: Color.from('hex','00ff00'),
amount: 0.4
})
// rgb { r: 153, g: 102, b: 0, a: 255, bitDepth: 8, max: 255 }
let color5 = Color.from('hex','ee5432').modify('blend', {
with: Color.from('rgb',[234, 100, 20, 64]),
amount: 1/3
}).to('hsv')
// hsv { h: 15, s: 83, v: 93, a: 75 }
let scheme1 = Color.from('rgb',[200, 180, 0]).scheme('splitComplement')
// [
// rgb { r: 200, g: 180, b: 0, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 120, b: 200, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 80, g: 0, b: 200, a: 255, bitDepth: 8, max: 255 }
// ]
let scheme2 = Color.from('hsl',[180, 80, 48]).scheme('tetradic', { angle: 40 })
// [
// hsl { h: 180, s: 80, l: 48, a: 100 },
// hsl { h: 220, s: 80, l: 48, a: 100 },
// hsl { h: 40, s: 80, l: 48, a: 100 },
// hsl { h: 0, s: 80, l: 48, a: 100 }
// ]
For all of the following examples, the same color is used (magenta / 0xFF00FF) to create the color.
All values are between 0 and ((2 ** bitDepth) - 1). With a default bit depth of 8, values are within 0-255. A color with a bit depth of 16 will have values ranging from 0-65535.
** 8-bit color is sometimes referred to as 24-bit or 32-bit (8 bits per channel, with 32-bit including an alpha channel). This package uses the more correct implementation of 32-bit meaning 32 bits per channel, and so generally most use cases would fall between 8 and 16 bit color depth.
** A special note: Adobe uses 15+1 bit depth for 16-bit color, where the last bit is simply added to the first 15 bits, hence the scale being
Color.from('rgb',[r, g, b, a?],{
bitDepth: number // optional, default = 8
})
.to('rgb',{
bitDepth: number, // optional, default = 8
round: boolean // optional, default = true
})
//e.g.
let color1 = Color.from('rgb',[255, 0, 255])
let color3 = color2.to('rgb')
let color4 = Color.from('rgb',[1023, 0, 1023], { bitDepth: 10 })
Hue value is between 0 and 360. Saturation, value, and alpha are between 0 and 100 (as in, percent).
Color.from('hsv',[h, s, v, a?])
.to('hsv',{
round: boolean // optional, default = true
})
//e.g.
let color1 = Color.from('hsv',[300, 100, 100])
let color3 = color2.to('hsv')
Hue value is between 0 and 360. Saturation, lightness, and alpha are between 0 and 100 (as in, percent).
Color.from('hsl',[h, s, l, a?])
.to('hsl',{
round: boolean // optional, default = true
})
//e.g.
let color1 = Color.from('hsl',[300, 100, 50])
let color3 = color2.to('hsl')
Hue value is between 0 and 360. Saturation, intensity, and alpha are between 0 and 100 (as in, percent).
Color.from('hsi',[h, s, v, a?])
.to('hsi',{
round: boolean // optional, default = true
})
//e.g.
let color1 = Color.from('hsi',[300, 100, 67])
let color3 = color2.to('hsi')
All values are between 0 and 100 (as in, percent).
** Calculations do not take pigment conversion into account and should not be used to reference printed colors.
Color.from('cmyk',[c, m, y, k])
.to('cmyk',{
round: boolean // optional, default = true
})
//e.g.
let color1 = Color.from('cmyk',[0, 100, 0, 0])
let color3 = color2.to('cmyk')
When normalized:
When not normalized:
Color.from('yiq', [y, i, q], {
normalized: boolean // optional, default = true
})
.to('yiq',{
normalize: boolean, // optional, default = true
round: boolean // optional, default = true (ignored/false if not normalized)
})
//e.g.
let color1 = Color.from('yiq',[105, 59, 128])
let color3 = color2.to('yiq')
let color4 = Color.from('yiq', [0.413, 0.2746, 0.5226], {normalized: false})
All values are between 0 and 1. XYZ is only defined within the constraints of a color space and reference white point of a standard illuminant. If one is not given, sRGB and D65 are used as the color space and standard illuminant.
It is not often useful to convert to XYZ, as XYZ defines real-world light and is typically then converted to a digital representation (most commonly RGB), but the functionality is present nonetheless.
Available Color Spaces and Stardard Illuminants below.
Color.from('xyz', [x, y, z], {
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
.to('xyz',{
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
//e.g.
let color1 = Color.from('xyz',[0.5928939, 0.2848479, 0.969638])
let color3 = color2.to('xyz')
let color4 = Color.from('xyz', [0.7589799, 0.3743439, 0.7643198], {
colorSpace: 'adobergb',
referenceWhite: 'd50'
})
Derived from XYZ, x and y are chromaticity values while Y is the tristimulous value of a color.
Available Color Spaces and Stardard Illuminants below.
Color.from('xyy', [x, y, Y], {
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
.to('xyy',{
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
//e.g.
let color1 = Color.from('xyy',[0.3209377411185291, 0.1541902211986945, 0.2848479])
let color3 = color2.to('xyy')
let color4 = Color.from('xyz', [
0.39995913879719036,
0.1972677588141419,
0.3743439
], {
colorSpace: 'adobergb',
referenceWhite: 'd50'
})
Derived from XYZ.
Available Color Spaces and Stardard Illuminants below.
Color.from('lab', [l, a, b], {
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
.to('lab',{
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
//e.g.
let color1 = Color.from('lab',[
60.32421212836874,
98.23431188800397,
-60.82489220885006
])
let color3 = color2.to('lab')
let color4 = Color.from('lab', [
67.60166164169028,
101.30709261827131,
-5.488771094285516
], {
colorSpace: 'adobergb',
referenceWhite: 'd50'
})
Derived from XYZ. L* is identical to L* in L*a*b*
Available Color Spaces and Stardard Illuminants below.
Color.from('luv', [l, u, v], {
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
.to('luv',{
colorSpace: string, // optional, default = 'srgb'
referenceWhite: string // optional, default = 'd65'
})
//e.g.
let color1 = Color.from('luv',[
60.32421212836874,
84.07139572483507,
-108.68333851910185
])
let color3 = color2.to('luv')
let color4 = Color.from('luv', [
67.60166164169028,
124.0201282170453,
-87.3117870588082
], {
colorSpace: 'adobergb',
referenceWhite: 'd50'
})
Also written Y'PbPr or YPBPR.
YPbPr conversions require Kb and Kr constants with the exception of converting to YCbCr. These values are not yet included in this package.
Color.from('ypbpr', [y, pb, pr])
.to('ypbpr',{
kb: number, // REQUIRED
kr: number // REQUIRED
})
// YCbCr conversion
.to('ycbcr',{
yLower: number, // optional, default = 16, lower bounds of Y'
yUpper: number, // optional, default = 235, upper bounds of Y'
cLower: number, // optional, default = 16, lower bounds of Cb and Cr
cUpper: number // optional, default = 240, upper bounds of Cb and Cr
})
//e.g.
let color1 = Color.from('ypbpr',[
0.2848,
0.3854278939426601,
0.45415290830581667
])
let color3 = color2.to('ypbpr',{
kb: 0.0722, // Rec709
kr: 0.2126 // Rec709
})
let color4 = color1.to('ycbcr')
let color5 = color1.to('ycbcr',{
yLower: 0,
yUpper: 255,
cLower: 0,
cUpper: 255
})
Also written Y'CbCr, Y Pb/Cb Pr/Cr, YCBCR, or Y'CBCR.
YCbCr conversions require Kb and Kr constants with the exception of converting to YPbPr. These values are not yet included in this package.
Color.from('ycbcr', [y, cb, cr])
.to('ycbcr',{
kb: number, // REQUIRED
kr: number // REQUIRED
})
// YPbPr conversion
.to('ypbpr',{
yLower: number, // optional, default = 16, lower bounds of Y'
yUpper: number, // optional, default = 235, upper bounds of Y'
cLower: number, // optional, default = 16, lower bounds of Cb and Cr
cUpper: number // optional, default = 240, upper bounds of Cb and Cr
})
//e.g.
let color1 = Color.from('ycbcr', [73, 226, 243])
let color3 = color2.to('ycbcr',{
kb: 0.0722, // Rec709
kr: 0.2126 // Rec709
})
let color4 = color1.to('ypbpr')
let color5 = color1.to('ypbpr',{
yLower: 0,
yUpper: 255,
cLower: 0,
cUpper: 255
})
For conversion to and from XYZ, xyY, L*a*b*, and L*u*v*, the following color spaces and standard illuminants have XYZ transformation matrices and reference white point vectors available:
| Color Space | Standard Illuminants |
|---|---|
| sRGB | D65, D50 |
| CIE RGB | E, D50 |
| Adobe RGB | D65, D50 |
| Apple RGB | D65, D50 |
| Best RGB | D50 |
| Bruce RGB | D65, D50 |
| ColorMatch RGB | D50 |
| Don RGB 4 | D50 |
| ECI RGB v2 | D50 |
| Ekta Space PS5 | D50 |
| NTSC RGB | C, D50 |
| PAL / SECAM RGB | D65, D50 |
| ProPhoto RGB | D50 |
| SMPTE-C RGB | D65, D50 |
| Wide Gamut RGB | D50 |
Color spaces and standard illuminant arguments are case-insensitive. Color space argument ignores any character not alphanumeric. Some common misspellings / words left out are also taken into account. (PAL / SECAM is equivalent to palsecamrgb.)
When blending two colors, the amount ∈ [0,1] refers to the percentage the second color is blended with the first. In other words, 0 means 0% of the second color and 100% of the first while 1 means 100% of the second color and 0% of the first.
let color3 = color1.modify('blend', {
with: color2, // REQUIRED, can be any color of any type
amount: number // optional, 0 - 1, defaults to 0.5
})
//e.g.
let color4 = Color.from('rgb',[255,0,0]).modify('blend', {
with: Color.from('hex','00ff00')
})
// rgb { r: 128, g: 128, b: 0, a: 255, bitDepth: 8, max: 255 }
let color5 = Color.from('hex','ee5432').modify('blend', {
with: Color.from('rgb',[234, 100, 20, 64]),
amount: 1/3
}).to('hsv')
// hsv { h: 15, s: 83, v: 93, a: 75 }
todo
todo
todo
todo
Schemes can be generated from any color type. All methods return an array of colors, each the same as the input type. (If calling method on a color of type hsl, all values of the returned array will be of type hsl.)
color.scheme(type: string)
// or
color.scheme(type: string, {
angle: number // optional, hue shift angle in degrees
})
Complementary color scheme generation has a fixed angle of 180°.
.scheme('complement') // angle = 180
// e.g.
let color1 = Color.from('rgb',[255,0,255]).scheme('complement')
// [
// rgb { r: 255, g: 0, b: 255, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 255, b: 0, a: 255, bitDepth: 8, max: 255 }
// ]
These three methods are synonyms with different default angles.
.scheme('analogous', {
angle: number // optional, default = 30
})
.scheme('triadic', {
angle: number // optional, default = 120
})
.scheme('splitcomplement', {
angle: number // optional, default = 150
})
// e.g.
let color1 = Color.from('rgb',[255,0,255]).scheme('analogous')
// [
// rgb { r: 255, g: 0, b: 255, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 128, g: 255, b: 0, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 255, b: 128, a: 255, bitDepth: 8, max: 255 }
// ]
let color2 = Color.from('rgb',[255,0,255]).scheme('triadic')
// [
// rgb { r: 255, g: 0, b: 255, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 255, g: 255, b: 0, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 255, b: 255, a: 255, bitDepth: 8, max: 255 }
// ]
let color3 = Color.from('rgb',[255,0,255]).scheme('splitcomplement',{angle: 160})
// [
// rgb { r: 255, g: 0, b: 255, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 85, g: 255, b: 0, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 255, b: 85, a: 255, bitDepth: 8, max: 255 }
// ]
These two methods are synonyms, but that the square method has a fixed angle of 90°.
.scheme('tetradic', {
angle: number // optional, default = 45
})
.scheme('square') // angle = 90
// e.g.
let color1 = Color.from('rgb',[255,0,255]).scheme('tetradic',{angle: 42})
// [
// rgb { r: 255, g: 0, b: 255, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 255, g: 0, b: 76, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 255, b: 179, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 255, b: 0, a: 255, bitDepth: 8, max: 255 }
// ]
let color2 = Color.from('rgb',[255,0,255]).scheme('square')
// [
// rgb { r: 255, g: 0, b: 255, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 255, g: 128, b: 0, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 128, b: 255, a: 255, bitDepth: 8, max: 255 },
// rgb { r: 0, g: 255, b: 0, a: 255, bitDepth: 8, max: 255 }
// ]
todo / not yet implemented
.scheme('tint',{
length: number, // number of colors in scheme
distance: number // 0-1, how far away from white to go
})
todo / not yet implemented
.scheme('shade',{
length: number, // number of colors in scheme
distance: number // 0-1, how far away from black to go
})
todo / not yet implemented
.scheme('tintshade',{
length: number, // number of colors in scheme
distance: number // 0-1, how far away from closest bound (white or black) to go
})
The following are the formulae used in the conversion algorithms. For succinctness, consider all values normalized ∈ [0, 1] unless stated otherwise.
to achieve R,G,B ∈ [0, 1]
X' = X / ((2 ** bitRate) - 1)
X = X' * ((2 ** bitRate) - 1)
V = max(R,G,B)
C = V - min(R,G,B)
S = | 0 if V = 0
| C / V otherwise
| 0 if C = 0
H = | (G - B) / C if V = R
| (B - R) / C if V = G
| (R - G) / C if V = B
p = V * (1 - S)
q = V * (1 - S * H)
t = V * (1 - S * (1 - H))
| (V,V,V) if S = 0
| (V,t,p) if H < 1
| (q,V,p) if 1 < H <= 2
(R,G,B) = | (p,V,t) if 2 < H <= 3
| (p,q,V) if 3 < H <= 4
| (t,p,V) if 4 < H <= 5
| (V,p,q) otherwise
V = max(R,G,B)
C = V - min(R,G,B)
L = V - C / 2
S = | 0 if L = 0 or L = 1
| (V - L) / min(L, 1 - L) otherwise
R,G,B = V if S = 0
otherwise
C = (1 - |2L - 1|) * S
x = C * (1 - |H mod 2 - 1|)
| (0,0,0) if H undefined
| (C,x,0) if 0 < H <= 1
| (x,C,0) if 1 < H <= 2
(R1,G1,B1) = | (0,C,x) if 2 < H <= 3
| (0,x,C) if 3 < H <= 4
| (x,0,C) if 4 < H <= 5
| (C,0,x) if 5 < H <= 6
m = L - C / 2
(R,G,B) = (R1 + m, G1 + m, B1 + m)
V = max(R,G,B)
C = V - min(R,G,B)
| 0 if C = 0
H = | ((G - B) / C) mod 6 if V = R
| ((B - R) / C) + 2 if V = G
| ((R - G) / C) + 4 if V = B
I = | 0 if C = 0
| (R + G + B) * (1 / 3) otherwise
z = 1 - |H mod 2 - 1|
C = (3I * S) / (1 + z)
x = C * z
| (0,0,0) if H undefined
| (C,x,0) if 0 < H <= 1
| (x,C,0) if 1 < H <= 2
(R1,G1,B1) = | (0,C,x) if 2 < H <= 3
| (0,x,C) if 3 < H <= 4
| (x,0,C) if 4 < H <= 5
| (C,0,x) if 5 < H <= 6
m = I * (1 - S)
(R,G,B) = (R1 + m, G1 + m, B1 + m)
L = V * (1 - S / 2)
S = | 0 if L = 0 or L = 1
| (V - L) / min(L, 1 - L) otherwise
V = L * S * min(L, 1 - L)
S = | 0 if V = 0
| 2 * (1 - L / V) otherwise
K = 1 - max(R,G,B)
C = | 0 if K = 1
| (1 - R - K) / (1 - K) otherwise
M = | 0 if K = 1
| (1 - G - K) / (1 - K) otherwise
Y = | 0 if K = 1
| (1 - B - K) / (1 - K) otherwise
R = (1 - C) * (1 - K)
G = (1 - M) * (1 - K)
B = (1 - Y) * (1 - K)
[Y] [0.299 0.587 0.114 ] [R]
[I] = [0.5959 -0.2746 -0.3213] * [G]
[Q] [0.2115 -0.5227 0.3112] [B]
Y ∈ [0,1]
I ∈ [-0.5957,0.5957]
Q ∈ [-0.5226,0.5226]
or, normalized
Y ∈ [0,255]
I ∈ [-128, 128]
Q ∈ [-128, 128]
Y ∈ [0,1]
I ∈ [-0.5957,0.5957]
Q ∈ [-0.5226,0.5226]
[R] [1 0.956 0.621] [Y]
[G] = [1 -0.272 -0.647] * [I]
[B] [1 -1.106 1.703] [Q]
M = 3x3 RGB to XYZ transformation matrix based on color space and standard illuminant reference white
for X = (R,G,B)
X' = | X / 12.92 if X <= 0.04045
| ((X + 0.055) / 1.055) ^ 2.4 otherwise
[X] [R']
[Y] = M * [G']
[Z] [B']
κ = 903.3, CIE-K
for X = (R,G,B)
X' = | 100 * (R / κ) if R <= 0.08
| ((R + 0.16) / 1.16) ^ 3 otherwise
[X] [R']
[Y] = M * [G']
[Z] [B']
γ based on target color space
for X = (R,G,B)
X' = X ^ γ
[X] [R']
[Y] = M * [G']
[Z] [B']
M = 3x3 XYZ to RGB transformation matrix based on color space and standard illuminant reference white
[R'] [X]
[G'] = M * [Y]
[B'] [Z]
for X' = (R',G',B')
X = | X' * 12.92 if X' <= 0.0031308
| (X' * 1.055) ^ (1 / 2.4) - 0.055 otherwise
[R'] [X]
[G'] = M * [Y]
[B'] [Z]
ϵ = 0.008856, CIE-E
κ = 903.3, CIE-K
for X' = (R',G',B')
X = | X' * κ / 100 if X' <= ϵ
| 1.16 * X' ^ (1/3) - 0.16 otherwise
γ based on target color space
[R'] [X]
[G'] = M * [Y]
[B'] [Z]
for X' = (R',G',B')
X = X' ^ (1 / γ)
x = X / (X + Y + Z)
y = Y / (X + Y + Z)
Y = Y
X = (x * Y) / y
Y = Y
Z = ((1 - x - y) * Y) / y
W is a 1x3 reference white vector based on standard illuminant
ϵ = 0.008856, CIE-E
κ = 903.3, CIE-K
X' = X / W[0]
Y' = Y / W[1]
Z' = Z / W[2]
f(n) = | n' ^ 1/3 if n > ϵ
| (κ * n' + 16) / 116 otherwise
L* = 116 * f(Y) - 16
a* = 500 * (f(X) - f(Y))
b* = 200 * (f(Y) - f(Z))
W is a 1x3 reference white vector based on standard illuminant
ϵ = 0.008856, CIE-E
κ = 903.3, CIE-K
L' = (L* + 16) / 116
a' = a* / 500 + L'
b' = L' - b* / 200
X' = | a' ^ 3 if a' ^ 3 > ϵ
| (116 * a' - 16) / κ otherwise
Y' = | (L' ^ 3 if L* > κ * ϵ
| L* * κ otherwise
Z' = | b' ^ 3 if b' ^ 3 > ϵ
| (116 * b' - 16) / κ otherwise
X = X' * W[0]
Y = Y' * W[1]
Z = Z' * W[2]
W is a 1x3 reference white vector based on standard illuminant
ϵ = 0.008856, CIE-E
κ = 903.3, CIE-K
Y' = Y / W[1]
d = X + 15 * Y + 3 * Z
u' = | 0 if d = 0
| 4X / d otherwise
v' = | 0 if d = 0
| 9Y / d otherwise
L* = | 116 * Y' ^ 1/3 if Y' > ϵ
| Y' * κ otherwise
u'r = (4 * W[1]) / (W[0] + 15 * W[1] + 3 * W[2])
v'r = (9 * W[1]) / (W[0] + 15 * W[1] + 3 * W[2])
u* = 13 * L* * (u' - u'r)
v* = 13 * L* * (v' - v'r)
W is a 1x3 reference white vector based on standard illuminant
ϵ = 0.008856, CIE-E
κ = 903.3, CIE-K
Y = | ((L* + 16) / 116) ^ 3 if L* > κ * ϵ
| L* / κ otherwise
u0 = (4 * W[0]) / (W[0] + 15 * W[1] + 3 * W[2])
v0 = (9 * W[0]) / (W[0] + 15 * W[1] + 3 * W[2])
a = 1/3 * (((52 * L*) / (u* + 13 * L* * u0))) - 1)
b = -5Y
c = -1/3
d = Y * (((39 * L*) / (v* + 13 * L* * v0)) - 5)
X = (d - b) / (a - c)
Z = X * a + b
Kb and Kr constants defined from target color space
Kg = 1 - Kb - Kr
Y = Kr * R + Kg * G + Kb * B
Pb = 0.5 * ((B - Y) / (1 - Kb))
Pr = 0.5 * ((R - Y) / (1 - Kr))
Scaling bounds given by conversion method / target space. Such as:
Y scaled to: 0 - 255 JPEG
16 - 235 Rec709
Cb, Cr scaled to: 0 - 255 JPEG
16 - 245 Rec709
Y scaled to: 0 - 1
Pb, Pr scaled to: -0.5 - 0.5
Kb and Kr constants defined from target color space
Kg = 1 - Kb - Kr
R = Y + (2 - 2Kr) * Pr
G = Y + (-1 * (Kb / Kg) * (2 - 2Kb)) * Pb + (-1 * (Kr / Kg) * (2 - 2Kr)) * Pr
B = Y + (2 - 2Kb) * Pb
git clone https://github.com/reiniiriarios/chromaticity-color-utilities.git
cd chromaticity-color-utilities
npm install
tsc
FAQs
Color utilities for Node.js
The npm package chromaticity-color-utilities receives a total of 21 weekly downloads. As such, chromaticity-color-utilities popularity was classified as not popular.
We found that chromaticity-color-utilities demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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