1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 // This file is available under and governed by the GNU General Public
26 // License version 2 only, as published by the Free Software Foundation.
27 // However, the following notice accompanied the original version of this
28 // file:
29 //
30 //---------------------------------------------------------------------------------
31 //
32 // Little Color Management System
33 // Copyright (c) 1998-2020 Marti Maria Saguer
34 //
35 // Permission is hereby granted, free of charge, to any person obtaining
36 // a copy of this software and associated documentation files (the "Software"),
37 // to deal in the Software without restriction, including without limitation
38 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
39 // and/or sell copies of the Software, and to permit persons to whom the Software
40 // is furnished to do so, subject to the following conditions:
41 //
42 // The above copyright notice and this permission notice shall be included in
43 // all copies or substantial portions of the Software.
44 //
45 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
46 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
47 // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
48 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
49 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
50 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
51 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
52 //
53 //---------------------------------------------------------------------------------
54 //
55
56 #include "lcms2_internal.h"
57
58
59 // D50 - Widely used
60 const cmsCIEXYZ* CMSEXPORT cmsD50_XYZ(void)
61 {
62 static cmsCIEXYZ D50XYZ = {cmsD50X, cmsD50Y, cmsD50Z};
63
64 return &D50XYZ;
65 }
66
67 const cmsCIExyY* CMSEXPORT cmsD50_xyY(void)
68 {
69 static cmsCIExyY D50xyY;
70
71 cmsXYZ2xyY(&D50xyY, cmsD50_XYZ());
72
73 return &D50xyY;
74 }
75
76 // Obtains WhitePoint from Temperature
77 cmsBool CMSEXPORT cmsWhitePointFromTemp(cmsCIExyY* WhitePoint, cmsFloat64Number TempK)
78 {
79 cmsFloat64Number x, y;
80 cmsFloat64Number T, T2, T3;
81 // cmsFloat64Number M1, M2;
82
83 _cmsAssert(WhitePoint != NULL);
84
85 T = TempK;
86 T2 = T*T; // Square
87 T3 = T2*T; // Cube
88
89 // For correlated color temperature (T) between 4000K and 7000K:
90
91 if (T >= 4000. && T <= 7000.)
92 {
93 x = -4.6070*(1E9/T3) + 2.9678*(1E6/T2) + 0.09911*(1E3/T) + 0.244063;
94 }
95 else
96 // or for correlated color temperature (T) between 7000K and 25000K:
97
98 if (T > 7000.0 && T <= 25000.0)
99 {
100 x = -2.0064*(1E9/T3) + 1.9018*(1E6/T2) + 0.24748*(1E3/T) + 0.237040;
101 }
102 else {
103 cmsSignalError(0, cmsERROR_RANGE, "cmsWhitePointFromTemp: invalid temp");
104 return FALSE;
105 }
106
107 // Obtain y(x)
108 y = -3.000*(x*x) + 2.870*x - 0.275;
109
110 // wave factors (not used, but here for futures extensions)
111
112 // M1 = (-1.3515 - 1.7703*x + 5.9114 *y)/(0.0241 + 0.2562*x - 0.7341*y);
113 // M2 = (0.0300 - 31.4424*x + 30.0717*y)/(0.0241 + 0.2562*x - 0.7341*y);
114
115 WhitePoint -> x = x;
116 WhitePoint -> y = y;
117 WhitePoint -> Y = 1.0;
118
119 return TRUE;
120 }
121
122
123
124 typedef struct {
125
126 cmsFloat64Number mirek; // temp (in microreciprocal kelvin)
127 cmsFloat64Number ut; // u coord of intersection w/ blackbody locus
128 cmsFloat64Number vt; // v coord of intersection w/ blackbody locus
129 cmsFloat64Number tt; // slope of ISOTEMPERATURE. line
130
131 } ISOTEMPERATURE;
132
133 static const ISOTEMPERATURE isotempdata[] = {
134 // {Mirek, Ut, Vt, Tt }
135 {0, 0.18006, 0.26352, -0.24341},
136 {10, 0.18066, 0.26589, -0.25479},
137 {20, 0.18133, 0.26846, -0.26876},
138 {30, 0.18208, 0.27119, -0.28539},
139 {40, 0.18293, 0.27407, -0.30470},
140 {50, 0.18388, 0.27709, -0.32675},
141 {60, 0.18494, 0.28021, -0.35156},
142 {70, 0.18611, 0.28342, -0.37915},
143 {80, 0.18740, 0.28668, -0.40955},
144 {90, 0.18880, 0.28997, -0.44278},
145 {100, 0.19032, 0.29326, -0.47888},
146 {125, 0.19462, 0.30141, -0.58204},
147 {150, 0.19962, 0.30921, -0.70471},
148 {175, 0.20525, 0.31647, -0.84901},
149 {200, 0.21142, 0.32312, -1.0182 },
150 {225, 0.21807, 0.32909, -1.2168 },
151 {250, 0.22511, 0.33439, -1.4512 },
152 {275, 0.23247, 0.33904, -1.7298 },
153 {300, 0.24010, 0.34308, -2.0637 },
154 {325, 0.24702, 0.34655, -2.4681 },
155 {350, 0.25591, 0.34951, -2.9641 },
156 {375, 0.26400, 0.35200, -3.5814 },
157 {400, 0.27218, 0.35407, -4.3633 },
158 {425, 0.28039, 0.35577, -5.3762 },
159 {450, 0.28863, 0.35714, -6.7262 },
160 {475, 0.29685, 0.35823, -8.5955 },
161 {500, 0.30505, 0.35907, -11.324 },
162 {525, 0.31320, 0.35968, -15.628 },
163 {550, 0.32129, 0.36011, -23.325 },
164 {575, 0.32931, 0.36038, -40.770 },
165 {600, 0.33724, 0.36051, -116.45 }
166 };
167
168 #define NISO sizeof(isotempdata)/sizeof(ISOTEMPERATURE)
169
170
171 // Robertson's method
172 cmsBool CMSEXPORT cmsTempFromWhitePoint(cmsFloat64Number* TempK, const cmsCIExyY* WhitePoint)
173 {
174 cmsUInt32Number j;
175 cmsFloat64Number us,vs;
176 cmsFloat64Number uj,vj,tj,di,dj,mi,mj;
177 cmsFloat64Number xs, ys;
178
179 _cmsAssert(WhitePoint != NULL);
180 _cmsAssert(TempK != NULL);
181
182 di = mi = 0;
183 xs = WhitePoint -> x;
184 ys = WhitePoint -> y;
185
186 // convert (x,y) to CIE 1960 (u,WhitePoint)
187
188 us = (2*xs) / (-xs + 6*ys + 1.5);
189 vs = (3*ys) / (-xs + 6*ys + 1.5);
190
191
192 for (j=0; j < NISO; j++) {
193
194 uj = isotempdata[j].ut;
195 vj = isotempdata[j].vt;
196 tj = isotempdata[j].tt;
197 mj = isotempdata[j].mirek;
198
199 dj = ((vs - vj) - tj * (us - uj)) / sqrt(1.0 + tj * tj);
200
201 if ((j != 0) && (di/dj < 0.0)) {
202
203 // Found a match
204 *TempK = 1000000.0 / (mi + (di / (di - dj)) * (mj - mi));
205 return TRUE;
206 }
207
208 di = dj;
209 mi = mj;
210 }
211
212 // Not found
213 return FALSE;
214 }
215
216
217 // Compute chromatic adaptation matrix using Chad as cone matrix
218
219 static
220 cmsBool ComputeChromaticAdaptation(cmsMAT3* Conversion,
221 const cmsCIEXYZ* SourceWhitePoint,
222 const cmsCIEXYZ* DestWhitePoint,
223 const cmsMAT3* Chad)
224
225 {
226
227 cmsMAT3 Chad_Inv;
228 cmsVEC3 ConeSourceXYZ, ConeSourceRGB;
229 cmsVEC3 ConeDestXYZ, ConeDestRGB;
230 cmsMAT3 Cone, Tmp;
231
232
233 Tmp = *Chad;
234 if (!_cmsMAT3inverse(&Tmp, &Chad_Inv)) return FALSE;
235
236 _cmsVEC3init(&ConeSourceXYZ, SourceWhitePoint -> X,
237 SourceWhitePoint -> Y,
238 SourceWhitePoint -> Z);
239
240 _cmsVEC3init(&ConeDestXYZ, DestWhitePoint -> X,
241 DestWhitePoint -> Y,
242 DestWhitePoint -> Z);
243
244 _cmsMAT3eval(&ConeSourceRGB, Chad, &ConeSourceXYZ);
245 _cmsMAT3eval(&ConeDestRGB, Chad, &ConeDestXYZ);
246
247 // Build matrix
248 _cmsVEC3init(&Cone.v[0], ConeDestRGB.n[0]/ConeSourceRGB.n[0], 0.0, 0.0);
249 _cmsVEC3init(&Cone.v[1], 0.0, ConeDestRGB.n[1]/ConeSourceRGB.n[1], 0.0);
250 _cmsVEC3init(&Cone.v[2], 0.0, 0.0, ConeDestRGB.n[2]/ConeSourceRGB.n[2]);
251
252
253 // Normalize
254 _cmsMAT3per(&Tmp, &Cone, Chad);
255 _cmsMAT3per(Conversion, &Chad_Inv, &Tmp);
256
257 return TRUE;
258 }
259
260 // Returns the final chrmatic adaptation from illuminant FromIll to Illuminant ToIll
261 // The cone matrix can be specified in ConeMatrix. If NULL, Bradford is assumed
262 cmsBool _cmsAdaptationMatrix(cmsMAT3* r, const cmsMAT3* ConeMatrix, const cmsCIEXYZ* FromIll, const cmsCIEXYZ* ToIll)
263 {
264 cmsMAT3 LamRigg = {{ // Bradford matrix
265 {{ 0.8951, 0.2664, -0.1614 }},
266 {{ -0.7502, 1.7135, 0.0367 }},
267 {{ 0.0389, -0.0685, 1.0296 }}
268 }};
269
270 if (ConeMatrix == NULL)
271 ConeMatrix = &LamRigg;
272
273 return ComputeChromaticAdaptation(r, FromIll, ToIll, ConeMatrix);
274 }
275
276 // Same as anterior, but assuming D50 destination. White point is given in xyY
277 static
278 cmsBool _cmsAdaptMatrixToD50(cmsMAT3* r, const cmsCIExyY* SourceWhitePt)
279 {
280 cmsCIEXYZ Dn;
281 cmsMAT3 Bradford;
282 cmsMAT3 Tmp;
283
284 cmsxyY2XYZ(&Dn, SourceWhitePt);
285
286 if (!_cmsAdaptationMatrix(&Bradford, NULL, &Dn, cmsD50_XYZ())) return FALSE;
287
288 Tmp = *r;
289 _cmsMAT3per(r, &Bradford, &Tmp);
290
291 return TRUE;
292 }
293
294 // Build a White point, primary chromas transfer matrix from RGB to CIE XYZ
295 // This is just an approximation, I am not handling all the non-linear
296 // aspects of the RGB to XYZ process, and assumming that the gamma correction
297 // has transitive property in the transformation chain.
298 //
299 // the alghoritm:
300 //
301 // - First I build the absolute conversion matrix using
302 // primaries in XYZ. This matrix is next inverted
303 // - Then I eval the source white point across this matrix
304 // obtaining the coeficients of the transformation
305 // - Then, I apply these coeficients to the original matrix
306 //
307 cmsBool _cmsBuildRGB2XYZtransferMatrix(cmsMAT3* r, const cmsCIExyY* WhitePt, const cmsCIExyYTRIPLE* Primrs)
308 {
309 cmsVEC3 WhitePoint, Coef;
310 cmsMAT3 Result, Primaries;
311 cmsFloat64Number xn, yn;
312 cmsFloat64Number xr, yr;
313 cmsFloat64Number xg, yg;
314 cmsFloat64Number xb, yb;
315
316 xn = WhitePt -> x;
317 yn = WhitePt -> y;
318 xr = Primrs -> Red.x;
319 yr = Primrs -> Red.y;
320 xg = Primrs -> Green.x;
321 yg = Primrs -> Green.y;
322 xb = Primrs -> Blue.x;
323 yb = Primrs -> Blue.y;
324
325 // Build Primaries matrix
326 _cmsVEC3init(&Primaries.v[0], xr, xg, xb);
327 _cmsVEC3init(&Primaries.v[1], yr, yg, yb);
328 _cmsVEC3init(&Primaries.v[2], (1-xr-yr), (1-xg-yg), (1-xb-yb));
329
330
331 // Result = Primaries ^ (-1) inverse matrix
332 if (!_cmsMAT3inverse(&Primaries, &Result))
333 return FALSE;
334
335
336 _cmsVEC3init(&WhitePoint, xn/yn, 1.0, (1.0-xn-yn)/yn);
337
338 // Across inverse primaries ...
339 _cmsMAT3eval(&Coef, &Result, &WhitePoint);
340
341 // Give us the Coefs, then I build transformation matrix
342 _cmsVEC3init(&r -> v[0], Coef.n[VX]*xr, Coef.n[VY]*xg, Coef.n[VZ]*xb);
343 _cmsVEC3init(&r -> v[1], Coef.n[VX]*yr, Coef.n[VY]*yg, Coef.n[VZ]*yb);
344 _cmsVEC3init(&r -> v[2], Coef.n[VX]*(1.0-xr-yr), Coef.n[VY]*(1.0-xg-yg), Coef.n[VZ]*(1.0-xb-yb));
345
346
347 return _cmsAdaptMatrixToD50(r, WhitePt);
348
349 }
350
351
352 // Adapts a color to a given illuminant. Original color is expected to have
353 // a SourceWhitePt white point.
354 cmsBool CMSEXPORT cmsAdaptToIlluminant(cmsCIEXYZ* Result,
355 const cmsCIEXYZ* SourceWhitePt,
356 const cmsCIEXYZ* Illuminant,
357 const cmsCIEXYZ* Value)
358 {
359 cmsMAT3 Bradford;
360 cmsVEC3 In, Out;
361
362 _cmsAssert(Result != NULL);
363 _cmsAssert(SourceWhitePt != NULL);
364 _cmsAssert(Illuminant != NULL);
365 _cmsAssert(Value != NULL);
366
367 if (!_cmsAdaptationMatrix(&Bradford, NULL, SourceWhitePt, Illuminant)) return FALSE;
368
369 _cmsVEC3init(&In, Value -> X, Value -> Y, Value -> Z);
370 _cmsMAT3eval(&Out, &Bradford, &In);
371
372 Result -> X = Out.n[0];
373 Result -> Y = Out.n[1];
374 Result -> Z = Out.n[2];
375
376 return TRUE;
377 }
378
379