1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
// 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 = Math.pow( ( var_R + 0.055 ) / 1.055, 2.4)
else var_R = var_R / 12.92
if ( var_G > 0.04045 ) var_G = Math.pow( ( var_G + 0.055 ) / 1.055, 2.4)
else var_G = var_G / 12.92
if ( var_B > 0.04045 ) var_B = Math.pow( ( 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 ( Math.pow(var_Y, 3) > 0.008856 ) var_Y = Math.pow(var_Y, 3)
else var_Y = ( var_Y - 16 / 116 ) / 7.787
if ( Math.pow(var_X, 3) > 0.008856 ) var_X = Math.pow(var_X, 3)
else var_X = ( var_X - 16 / 116 ) / 7.787
if ( Math.pow(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 = Math.min( var_R, var_G, var_B ) //Min. value of RGB
var var_Max = Math.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]
}
|
