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// http://www.easyrgb.com/index.php?X=MATH&H=01#text1
function rgb(x,y,z){
r=x; g=y; b=z
}
function rgbref(rgb){
r=rgb[0]; g=rgb[1]; b=rgb[2];
}
function black(){ rgb(0,0,0) }
function white(){ rgb(255,255,255) }
function red(){ rgb(255,0,0) }
function gray(n){ n<1&&(n*=255);rgb(n,n,n) }
function rgb2xyz(rgb){
var var_R = ( rgb[0] / 255 ) //R from 0 to 255
var var_G = ( rgb[1] / 255 ) //G from 0 to 255
var var_B = ( rgb[2] / 255 ) //B from 0 to 255
if ( var_R > 0.04045 ) var_R = ( ( var_R + 0.055 ) / 1.055 ) ^ 2.4
else var_R = var_R / 12.92
if ( var_G > 0.04045 ) var_G = ( ( var_G + 0.055 ) / 1.055 ) ^ 2.4
else var_G = var_G / 12.92
if ( var_B > 0.04045 ) var_B = ( ( var_B + 0.055 ) / 1.055 ) ^ 2.4
else var_B = var_B / 12.92
var_R = var_R * 100
var_G = var_G * 100
var_B = var_B * 100
//Observer. = 2°, Illuminant = D65
var x = var_R * 0.4124 + var_G * 0.3576 + var_B * 0.1805
var y = var_R * 0.2126 + var_G * 0.7152 + var_B * 0.0722
var z = var_R * 0.0193 + var_G * 0.1192 + var_B * 0.9505
return [x,y,z];
}
function xyz2rgb(xyz){
var var_X = xyz[0] / 100 //X from 0 to 95.047 (Observer = 2°, Illuminant = D65)
var var_Y = xyz[1] / 100 //Y from 0 to 100.000
var var_Z = xyz[2] / 100 //Z from 0 to 108.883
var_R = var_X * 3.2406 + var_Y * -1.5372 + var_Z * -0.4986
var_G = var_X * -0.9689 + var_Y * 1.8758 + var_Z * 0.0415
var_B = var_X * 0.0557 + var_Y * -0.2040 + var_Z * 1.0570
if ( var_R > 0.0031308 ) var_R = 1.055 * Math.pow( var_R, 1 / 2.4 ) - 0.055
else var_R = 12.92 * var_R
if ( var_G > 0.0031308 ) var_G = 1.055 * Math.pow( var_G, 1 / 2.4 ) - 0.055
else var_G = 12.92 * var_G
if ( var_B > 0.0031308 ) var_B = 1.055 * Math.pow( var_B, 1 / 2.4 ) - 0.055
else var_B = 12.92 * var_B
var r = clamp(var_R * 255, 0, 255)
var g = clamp(var_G * 255, 0, 255)
var b = clamp(var_B * 255, 0, 255)
return [r,g,b]
}
function xyz2hunterlab (XYZ) {
var X = XYZ[0]
var Y = XYZ[1] || 1e-6 // otherwise divide-by-zero error when converting rgb(0,0,0)
var Z = XYZ[2]
var L = 10 * sqrt( Y )
var a = 17.5 * ( ( ( 1.02 * X ) - Y ) / sqrt( Y ) )
var b = 7 * ( ( Y - ( 0.847 * Z ) ) / sqrt( Y ) )
return [L,a,b]
}
function hunterlab2xyz (Lab) {
var L = Lab[0]
var a = Lab[1]
var b = Lab[2]
var_Y = L / 10
var_X = a / 17.5 * L / 10
var_Z = b / 7 * L / 10
Y = Math.pow(var_Y, 2)
X = ( var_X + Y ) / 1.02
Z = -( var_Z - Y ) / 0.847
return [X,Y,Z]
}
// Daylight Illuminant (D65)
var REF_X = 95.047
var REF_Y = 100.000
var REF_Z = 108.883
function xyz2cielab (xyz) {
var var_X = xyz[0] / ref_X //ref_X = 95.047 Observer= 2°, Illuminant= D65
var var_Y = xyz[1] / ref_Y //ref_Y = 100.000
var var_Z = xyz[2] / ref_Z //ref_Z = 108.883
if ( var_X > 0.008856 ) var_X = Math.pow( var_X, 1/3 )
else var_X = ( 7.787 * var_X ) + ( 16 / 116 )
if ( var_Y > 0.008856 ) var_Y = Math.pow( var_Y, 1/3 )
else var_Y = ( 7.787 * var_Y ) + ( 16 / 116 )
if ( var_Z > 0.008856 ) var_Z = Math.pow(var_Z, 1/3 )
else var_Z = ( 7.787 * var_Z ) + ( 16 / 116 )
var L = ( 116 * var_Y ) - 16
var a = 500 * ( var_X - var_Y )
var b = 200 * ( var_Y - var_Z )
return [L,a,b]
}
function cielab2xyz (lab){
var var_Y = ( lab[0] + 16 ) / 116
var var_X = lab[1] / 500 + var_Y
var var_Z = var_Y - lab[2] / 200
if ( var_Y^3 > 0.008856 ) var_Y = Math.pow(var_Y, 3)
else var_Y = ( var_Y - 16 / 116 ) / 7.787
if ( var_X^3 > 0.008856 ) var_X = Math.pow(var_X, 3)
else var_X = ( var_X - 16 / 116 ) / 7.787
if ( var_Z^3 > 0.008856 ) var_Z = Math.pow(var_Z, 3)
else var_Z = ( var_Z - 16 / 116 ) / 7.787
var x = REF_X * var_X //ref_X = 95.047 Observer= 2°, Illuminant= D65
var y = REF_Y * var_Y //ref_Y = 100.000
var z = REF_Z * var_Z //ref_Z = 108.883
return [x,y,z]
}
function rgb2hsl (RGB){
var R = RGB[0]
var G = RGB[1]
var B = RGB[2]
var var_R = ( R / 255 ) //RGB from 0 to 255
var var_G = ( G / 255 )
var var_B = ( B / 255 )
var var_Min = min( var_R, var_G, var_B ) //Min. value of RGB
var var_Max = max( var_R, var_G, var_B ) //Max. value of RGB
var del_Max = var_Max - var_Min //Delta RGB value
var H,S;
var L = ( var_Max + var_Min ) / 2
if ( del_Max == 0 ) //This is a gray, no chroma...
{
H = 0 //HSL results from 0 to 1
S = 0
}
else //Chromatic data...
{
if ( L < 0.5 ) S = del_Max / ( var_Max + var_Min )
else S = del_Max / ( 2 - var_Max - var_Min )
var del_R = ( ( ( var_Max - var_R ) / 6 ) + ( del_Max / 2 ) ) / del_Max
var del_G = ( ( ( var_Max - var_G ) / 6 ) + ( del_Max / 2 ) ) / del_Max
var del_B = ( ( ( var_Max - var_B ) / 6 ) + ( del_Max / 2 ) ) / del_Max
if ( var_R == var_Max ) H = del_B - del_G
else if ( var_G == var_Max ) H = ( 1 / 3 ) + del_R - del_B
else if ( var_B == var_Max ) H = ( 2 / 3 ) + del_G - del_R
if ( H < 0 ) H += 1
if ( H > 1 ) H -= 1
}
return [H,S,L]
}
function hsl2rgb (H, S, L) {
var R,G,B;
var var_1, var_2;
if ( S == 0 ) { //HSL from 0 to 1
R = L * 255 //RGB results from 0 to 255
G = L * 255
B = L * 255
}
else {
if ( L < 0.5 ) var_2 = L * ( 1 + S )
else var_2 = ( L + S ) - ( S * L )
var_1 = 2 * L - var_2
R = 255 * hue2rgb( var_1, var_2, H + ( 1 / 3 ) )
G = 255 * hue2rgb( var_1, var_2, H )
B = 255 * hue2rgb( var_1, var_2, H - ( 1 / 3 ) )
}
return [R,G,B]
}
function hue2rgb( v1, v2, vH ) {
if ( vH < 0 ) vH += 1
if ( vH > 1 ) vH -= 1
if ( ( 6 * vH ) < 1 ) return ( v1 + ( v2 - v1 ) * 6 * vH )
if ( ( 2 * vH ) < 1 ) return ( v2 )
if ( ( 3 * vH ) < 2 ) return ( v1 + ( v2 - v1 ) * ( ( 2 / 3 ) - vH ) * 6 )
return ( v1 )
}
function rgb2cmy (R,G,B){
if (R.length) {
B = R[2]
G = R[1]
R = R[0]
}
var C = 1 - ( R / 255 )
var M = 1 - ( G / 255 )
var Y = 1 - ( B / 255 )
return [C,M,Y]
}
function cmy2rgb (C,M,Y){
if (C.length) {
Y = C[2]
M = C[1]
C = C[0]
}
var R = ( 1 - C ) * 255
var G = ( 1 - M ) * 255
var B = ( 1 - Y ) * 255
return [R,G,B]
}
function cmy2cmyk (C,M,Y) {
if (C.length) {
Y = C[2]
M = C[1]
C = C[0]
}
var var_K = 1
if ( C < var_K ) var_K = C
if ( M < var_K ) var_K = M
if ( Y < var_K ) var_K = Y
if ( var_K == 1 ) { //Black
C = 0
M = 0
Y = 0
}
else {
C = ( C - var_K ) / ( 1 - var_K )
M = ( M - var_K ) / ( 1 - var_K )
Y = ( Y - var_K ) / ( 1 - var_K )
}
var K = var_K
return [C,M,Y,K]
}
function cmyk2cmy (C,M,Y,K) {
if (C.length) {
K = C[3]
Y = C[2]
M = C[1]
C = C[0]
}
var C = ( C * ( 1 - K ) + K )
var M = ( M * ( 1 - K ) + K )
var Y = ( Y * ( 1 - K ) + K )
return [C,M,Y]
}
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