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|
//
// Little cms
// Copyright (C) 1998-2007 Marti Maria
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#include "lcms.h"
// Conversions
void LCMSEXPORT cmsXYZ2xyY(LPcmsCIExyY Dest, const cmsCIEXYZ* Source)
{
double ISum;
ISum = 1./(Source -> X + Source -> Y + Source -> Z);
Dest -> x = (Source -> X) * ISum;
Dest -> y = (Source -> Y) * ISum;
Dest -> Y = Source -> Y;
}
void LCMSEXPORT cmsxyY2XYZ(LPcmsCIEXYZ Dest, const cmsCIExyY* Source)
{
Dest -> X = (Source -> x / Source -> y) * Source -> Y;
Dest -> Y = Source -> Y;
Dest -> Z = ((1 - Source -> x - Source -> y) / Source -> y) * Source -> Y;
}
// Obtains WhitePoint from Temperature
LCMSBOOL LCMSEXPORT cmsWhitePointFromTemp(int TempK, LPcmsCIExyY WhitePoint)
{
double x, y;
double T, T2, T3;
// double M1, M2;
// No optimization provided.
T = TempK;
T2 = T*T; // Square
T3 = T2*T; // Cube
// For correlated color temperature (T) between 4000K and 7000K:
if (T >= 4000. && T <= 7000.)
{
x = -4.6070*(1E9/T3) + 2.9678*(1E6/T2) + 0.09911*(1E3/T) + 0.244063;
}
else
// or for correlated color temperature (T) between 7000K and 25000K:
if (T > 7000.0 && T <= 25000.0)
{
x = -2.0064*(1E9/T3) + 1.9018*(1E6/T2) + 0.24748*(1E3/T) + 0.237040;
}
else {
cmsSignalError(LCMS_ERRC_ABORTED, "cmsWhitePointFromTemp: invalid temp");
return FALSE;
}
// Obtain y(x)
y = -3.000*(x*x) + 2.870*x - 0.275;
// wave factors (not used, but here for futures extensions)
// M1 = (-1.3515 - 1.7703*x + 5.9114 *y)/(0.0241 + 0.2562*x - 0.7341*y);
// M2 = (0.0300 - 31.4424*x + 30.0717*y)/(0.0241 + 0.2562*x - 0.7341*y);
// Fill WhitePoint struct
WhitePoint -> x = x;
WhitePoint -> y = y;
WhitePoint -> Y = 1.0;
return TRUE;
}
// Build a White point, primary chromas transfer matrix from RGB to CIE XYZ
// This is just an approximation, I am not handling all the non-linear
// aspects of the RGB to XYZ process, and assumming that the gamma correction
// has transitive property in the tranformation chain.
//
// the alghoritm:
//
// - First I build the absolute conversion matrix using
// primaries in XYZ. This matrix is next inverted
// - Then I eval the source white point across this matrix
// obtaining the coeficients of the transformation
// - Then, I apply these coeficients to the original matrix
LCMSBOOL LCMSEXPORT cmsBuildRGB2XYZtransferMatrix(LPMAT3 r, LPcmsCIExyY WhitePt,
LPcmsCIExyYTRIPLE Primrs)
{
VEC3 WhitePoint, Coef;
MAT3 Result, Primaries;
double xn, yn;
double xr, yr;
double xg, yg;
double xb, yb;
xn = WhitePt -> x;
yn = WhitePt -> y;
xr = Primrs -> Red.x;
yr = Primrs -> Red.y;
xg = Primrs -> Green.x;
yg = Primrs -> Green.y;
xb = Primrs -> Blue.x;
yb = Primrs -> Blue.y;
// Build Primaries matrix
VEC3init(&Primaries.v[0], xr, xg, xb);
VEC3init(&Primaries.v[1], yr, yg, yb);
VEC3init(&Primaries.v[2], (1-xr-yr), (1-xg-yg), (1-xb-yb));
// Result = Primaries ^ (-1) inverse matrix
if (!MAT3inverse(&Primaries, &Result))
return FALSE;
VEC3init(&WhitePoint, xn/yn, 1.0, (1.0-xn-yn)/yn);
// Across inverse primaries ...
MAT3eval(&Coef, &Result, &WhitePoint);
// Give us the Coefs, then I build transformation matrix
VEC3init(&r -> v[0], Coef.n[VX]*xr, Coef.n[VY]*xg, Coef.n[VZ]*xb);
VEC3init(&r -> v[1], Coef.n[VX]*yr, Coef.n[VY]*yg, Coef.n[VZ]*yb);
VEC3init(&r -> v[2], Coef.n[VX]*(1.0-xr-yr), Coef.n[VY]*(1.0-xg-yg), Coef.n[VZ]*(1.0-xb-yb));
return TRUE;
}
// Compute chromatic adaptation matrix using Chad as cone matrix
static
void ComputeChromaticAdaptation(LPMAT3 Conversion,
LPcmsCIEXYZ SourceWhitePoint,
LPcmsCIEXYZ DestWhitePoint,
LPMAT3 Chad)
{
MAT3 Chad_Inv;
VEC3 ConeSourceXYZ, ConeSourceRGB;
VEC3 ConeDestXYZ, ConeDestRGB;
MAT3 Cone, Tmp;
Tmp = *Chad;
MAT3inverse(&Tmp, &Chad_Inv);
VEC3init(&ConeSourceXYZ, SourceWhitePoint -> X,
SourceWhitePoint -> Y,
SourceWhitePoint -> Z);
VEC3init(&ConeDestXYZ, DestWhitePoint -> X,
DestWhitePoint -> Y,
DestWhitePoint -> Z);
MAT3eval(&ConeSourceRGB, Chad, &ConeSourceXYZ);
MAT3eval(&ConeDestRGB, Chad, &ConeDestXYZ);
// Build matrix
VEC3init(&Cone.v[0], ConeDestRGB.n[0]/ConeSourceRGB.n[0], 0.0, 0.0);
VEC3init(&Cone.v[1], 0.0, ConeDestRGB.n[1]/ConeSourceRGB.n[1], 0.0);
VEC3init(&Cone.v[2], 0.0, 0.0, ConeDestRGB.n[2]/ConeSourceRGB.n[2]);
// Normalize
MAT3per(&Tmp, &Cone, Chad);
MAT3per(Conversion, &Chad_Inv, &Tmp);
}
// Returns the final chrmatic adaptation from illuminant FromIll to Illuminant ToIll
// The cone matrix can be specified in ConeMatrix. If NULL, Bradford is assumed
LCMSBOOL cmsAdaptationMatrix(LPMAT3 r, LPMAT3 ConeMatrix, LPcmsCIEXYZ FromIll, LPcmsCIEXYZ ToIll)
{
MAT3 LamRigg = {{ // Bradford matrix
{{ 0.8951, 0.2664, -0.1614 }},
{{ -0.7502, 1.7135, 0.0367 }},
{{ 0.0389, -0.0685, 1.0296 }}
}};
if (ConeMatrix == NULL)
ConeMatrix = &LamRigg;
ComputeChromaticAdaptation(r, FromIll, ToIll, ConeMatrix);
return TRUE;
}
// Same as anterior, but assuming D50 destination. White point is given in xyY
LCMSBOOL cmsAdaptMatrixToD50(LPMAT3 r, LPcmsCIExyY SourceWhitePt)
{
cmsCIEXYZ Dn;
MAT3 Bradford;
MAT3 Tmp;
cmsxyY2XYZ(&Dn, SourceWhitePt);
cmsAdaptationMatrix(&Bradford, NULL, &Dn, cmsD50_XYZ());
Tmp = *r;
MAT3per(r, &Bradford, &Tmp);
return TRUE;
}
// Same as anterior, but assuming D50 source. White point is given in xyY
LCMSBOOL cmsAdaptMatrixFromD50(LPMAT3 r, LPcmsCIExyY DestWhitePt)
{
cmsCIEXYZ Dn;
MAT3 Bradford;
MAT3 Tmp;
cmsxyY2XYZ(&Dn, DestWhitePt);
cmsAdaptationMatrix(&Bradford, NULL, cmsD50_XYZ(), &Dn);
Tmp = *r;
MAT3per(r, &Bradford, &Tmp);
return TRUE;
}
// Adapts a color to a given illuminant. Original color is expected to have
// a SourceWhitePt white point.
LCMSBOOL LCMSEXPORT cmsAdaptToIlluminant(LPcmsCIEXYZ Result,
LPcmsCIEXYZ SourceWhitePt,
LPcmsCIEXYZ Illuminant,
LPcmsCIEXYZ Value)
{
MAT3 Bradford;
VEC3 In, Out;
// BradfordLamRiggChromaticAdaptation(&Bradford, SourceWhitePt, Illuminant);
cmsAdaptationMatrix(&Bradford, NULL, SourceWhitePt, Illuminant);
VEC3init(&In, Value -> X, Value -> Y, Value -> Z);
MAT3eval(&Out, &Bradford, &In);
Result -> X = Out.n[0];
Result -> Y = Out.n[1];
Result -> Z = Out.n[2];
return TRUE;
}
typedef struct {
double mirek; // temp (in microreciprocal kelvin)
double ut; // u coord of intersection w/ blackbody locus
double vt; // v coord of intersection w/ blackbody locus
double tt; // slope of ISOTEMPERATURE. line
} ISOTEMPERATURE,FAR* LPISOTEMPERATURE;
static ISOTEMPERATURE isotempdata[] = {
// {Mirek, Ut, Vt, Tt }
{0, 0.18006, 0.26352, -0.24341},
{10, 0.18066, 0.26589, -0.25479},
{20, 0.18133, 0.26846, -0.26876},
{30, 0.18208, 0.27119, -0.28539},
{40, 0.18293, 0.27407, -0.30470},
{50, 0.18388, 0.27709, -0.32675},
{60, 0.18494, 0.28021, -0.35156},
{70, 0.18611, 0.28342, -0.37915},
{80, 0.18740, 0.28668, -0.40955},
{90, 0.18880, 0.28997, -0.44278},
{100, 0.19032, 0.29326, -0.47888},
{125, 0.19462, 0.30141, -0.58204},
{150, 0.19962, 0.30921, -0.70471},
{175, 0.20525, 0.31647, -0.84901},
{200, 0.21142, 0.32312, -1.0182 },
{225, 0.21807, 0.32909, -1.2168 },
{250, 0.22511, 0.33439, -1.4512 },
{275, 0.23247, 0.33904, -1.7298 },
{300, 0.24010, 0.34308, -2.0637 },
{325, 0.24702, 0.34655, -2.4681 },
{350, 0.25591, 0.34951, -2.9641 },
{375, 0.26400, 0.35200, -3.5814 },
{400, 0.27218, 0.35407, -4.3633 },
{425, 0.28039, 0.35577, -5.3762 },
{450, 0.28863, 0.35714, -6.7262 },
{475, 0.29685, 0.35823, -8.5955 },
{500, 0.30505, 0.35907, -11.324 },
{525, 0.31320, 0.35968, -15.628 },
{550, 0.32129, 0.36011, -23.325 },
{575, 0.32931, 0.36038, -40.770 },
{600, 0.33724, 0.36051, -116.45 }
};
#define NISO sizeof(isotempdata)/sizeof(ISOTEMPERATURE)
// Robertson's method
static
double Robertson(LPcmsCIExyY v)
{
int j;
double us,vs;
double uj,vj,tj,di,dj,mi,mj;
double Tc = -1, xs, ys;
di = mi = 0;
xs = v -> x;
ys = v -> y;
// convert (x,y) to CIE 1960 (u,v)
us = (2*xs) / (-xs + 6*ys + 1.5);
vs = (3*ys) / (-xs + 6*ys + 1.5);
for (j=0; j < NISO; j++) {
uj = isotempdata[j].ut;
vj = isotempdata[j].vt;
tj = isotempdata[j].tt;
mj = isotempdata[j].mirek;
dj = ((vs - vj) - tj * (us - uj)) / sqrt(1 + tj*tj);
if ((j!=0) && (di/dj < 0.0)) {
Tc = 1000000.0 / (mi + (di / (di - dj)) * (mj - mi));
break;
}
di = dj;
mi = mj;
}
if (j == NISO) return -1;
return Tc;
}
static
LCMSBOOL InRange(LPcmsCIExyY a, LPcmsCIExyY b, double tolerance)
{
double dist_x, dist_y;
dist_x = fabs(a->x - b->x);
dist_y = fabs(a->y - b->y);
return (tolerance >= dist_x * dist_x + dist_y * dist_y);
}
typedef struct {
char Name[30];
cmsCIExyY Val;
} WHITEPOINTS,FAR *LPWHITEPOINTS;
static
int FromD40toD150(LPWHITEPOINTS pts)
{
int i, n;
n = 0;
for (i=40; i < 150; i ++)
{
sprintf(pts[n].Name, "D%d", i);
cmsWhitePointFromTemp((int) (i*100.0), &pts[n].Val);
n++;
}
return n;
}
// To be removed in future versions
void _cmsIdentifyWhitePoint(char *Buffer, LPcmsCIEXYZ WhitePt)
{
int i, n;
cmsCIExyY Val;
double T;
WHITEPOINTS SomeIlluminants[140] = {
{"CIE illuminant A", {0.4476, 0.4074, 1.0}},
{"CIE illuminant C", {0.3101, 0.3162, 1.0}},
{"D65 (daylight)", {0.3127, 0.3291, 1.0}},
};
n = FromD40toD150(&SomeIlluminants[3]) + 3;
cmsXYZ2xyY(&Val, WhitePt);
Val.Y = 1.;
for (i=0; i < n; i++)
{
if (InRange(&Val, &SomeIlluminants[i].Val, 0.000005))
{
strcpy(Buffer, "WhitePoint : ");
strcat(Buffer, SomeIlluminants[i].Name);
return;
}
}
T = Robertson(&Val);
if (T > 0)
sprintf(Buffer, "White point near %dK", (int) T);
else
{
sprintf(Buffer, "Unknown white point (X:%1.2g, Y:%1.2g, Z:%1.2g)",
WhitePt -> X, WhitePt -> Y, WhitePt -> Z);
}
}
// Use darker colorant to obtain black point
static
int BlackPointAsDarkerColorant(cmsHPROFILE hInput,
int Intent,
LPcmsCIEXYZ BlackPoint,
DWORD dwFlags)
{
WORD *Black, *White;
cmsHTRANSFORM xform;
icColorSpaceSignature Space;
int nChannels;
DWORD dwFormat;
cmsHPROFILE hLab;
cmsCIELab Lab;
cmsCIEXYZ BlackXYZ, MediaWhite;
// If the profile does not support input direction, assume Black point 0
if (!cmsIsIntentSupported(hInput, Intent, LCMS_USED_AS_INPUT)) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return 0;
}
// Try to get black by using black colorant
Space = cmsGetColorSpace(hInput);
if (!_cmsEndPointsBySpace(Space, &White, &Black, &nChannels)) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return 0;
}
dwFormat = CHANNELS_SH(nChannels)|BYTES_SH(2);
hLab = cmsCreateLabProfile(NULL);
xform = cmsCreateTransform(hInput, dwFormat,
hLab, TYPE_Lab_DBL, Intent, cmsFLAGS_NOTPRECALC);
cmsDoTransform(xform, Black, &Lab, 1);
// Force it to be neutral, clip to max. L* of 50
Lab.a = Lab.b = 0;
if (Lab.L > 50) Lab.L = 50;
cmsCloseProfile(hLab);
cmsDeleteTransform(xform);
cmsLab2XYZ(NULL, &BlackXYZ, &Lab);
if (Intent == INTENT_ABSOLUTE_COLORIMETRIC) {
*BlackPoint = BlackXYZ;
}
else {
if (!(dwFlags & LCMS_BPFLAGS_D50_ADAPTED)) {
cmsTakeMediaWhitePoint(&MediaWhite, hInput);
cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &BlackXYZ);
}
else
*BlackPoint = BlackXYZ;
}
return 1;
}
// Get a black point of output CMYK profile, discounting any ink-limiting embedded
// in the profile. For doing that, use perceptual intent in input direction:
// Lab (0, 0, 0) -> [Perceptual] Profile -> CMYK -> [Rel. colorimetric] Profile -> Lab
static
int BlackPointUsingPerceptualBlack(LPcmsCIEXYZ BlackPoint,
cmsHPROFILE hProfile,
DWORD dwFlags)
{
cmsHTRANSFORM hPercLab2CMYK, hRelColCMYK2Lab;
cmsHPROFILE hLab;
cmsCIELab LabIn, LabOut;
WORD CMYK[MAXCHANNELS];
cmsCIEXYZ BlackXYZ, MediaWhite;
if (!cmsIsIntentSupported(hProfile, INTENT_PERCEPTUAL, LCMS_USED_AS_INPUT)) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return 0;
}
hLab = cmsCreateLabProfile(NULL);
hPercLab2CMYK = cmsCreateTransform(hLab, TYPE_Lab_DBL,
hProfile, TYPE_CMYK_16,
INTENT_PERCEPTUAL, cmsFLAGS_NOTPRECALC);
hRelColCMYK2Lab = cmsCreateTransform(hProfile, TYPE_CMYK_16,
hLab, TYPE_Lab_DBL,
INTENT_RELATIVE_COLORIMETRIC, cmsFLAGS_NOTPRECALC);
LabIn.L = LabIn.a = LabIn.b = 0;
cmsDoTransform(hPercLab2CMYK, &LabIn, CMYK, 1);
cmsDoTransform(hRelColCMYK2Lab, CMYK, &LabOut, 1);
if (LabOut.L > 50) LabOut.L = 50;
LabOut.a = LabOut.b = 0;
cmsDeleteTransform(hPercLab2CMYK);
cmsDeleteTransform(hRelColCMYK2Lab);
cmsCloseProfile(hLab);
cmsLab2XYZ(NULL, &BlackXYZ, &LabOut);
if (!(dwFlags & LCMS_BPFLAGS_D50_ADAPTED)){
cmsTakeMediaWhitePoint(&MediaWhite, hProfile);
cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &BlackXYZ);
}
else
*BlackPoint = BlackXYZ;
return 1;
}
// Get Perceptual black of v4 profiles.
static
int GetV4PerceptualBlack(LPcmsCIEXYZ BlackPoint, cmsHPROFILE hProfile, DWORD dwFlags)
{
if (dwFlags & LCMS_BPFLAGS_D50_ADAPTED) {
BlackPoint->X = PERCEPTUAL_BLACK_X;
BlackPoint->Y = PERCEPTUAL_BLACK_Y;
BlackPoint->Z = PERCEPTUAL_BLACK_Z;
}
else {
cmsCIEXYZ D50BlackPoint, MediaWhite;
cmsTakeMediaWhitePoint(&MediaWhite, hProfile);
D50BlackPoint.X = PERCEPTUAL_BLACK_X;
D50BlackPoint.Y = PERCEPTUAL_BLACK_Y;
D50BlackPoint.Z = PERCEPTUAL_BLACK_Z;
// Obtain the absolute XYZ. Adapt perceptual black back from D50 to whatever media white
cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &D50BlackPoint);
}
return 1;
}
// This function shouldn't exist at all -- there is such quantity of broken
// profiles on black point tag, that we must somehow fix chromaticity to
// avoid huge tint when doing Black point compensation. This function does
// just that. There is a special flag for using black point tag, but turned
// off by default because it is bogus on most profiles. The detection algorithm
// involves to turn BP to neutral and to use only L component.
int cmsDetectBlackPoint(LPcmsCIEXYZ BlackPoint, cmsHPROFILE hProfile, int Intent, DWORD dwFlags)
{
// v4 + perceptual & saturation intents does have its own black point, and it is
// well specified enough to use it.
if ((cmsGetProfileICCversion(hProfile) >= 0x4000000) &&
(Intent == INTENT_PERCEPTUAL || Intent == INTENT_SATURATION)) {
// Matrix shaper share MRC & perceptual intents
if (_cmsIsMatrixShaper(hProfile))
return BlackPointAsDarkerColorant(hProfile, INTENT_RELATIVE_COLORIMETRIC, BlackPoint, cmsFLAGS_NOTPRECALC);
// CLUT based - Get perceptual black point (fixed value)
return GetV4PerceptualBlack(BlackPoint, hProfile, dwFlags);
}
#ifdef HONOR_BLACK_POINT_TAG
// v2, v4 rel/abs colorimetric
if (cmsIsTag(hProfile, icSigMediaBlackPointTag) &&
Intent == INTENT_RELATIVE_COLORIMETRIC) {
cmsCIEXYZ BlackXYZ, UntrustedBlackPoint, TrustedBlackPoint, MediaWhite;
cmsCIELab Lab;
// If black point is specified, then use it,
cmsTakeMediaBlackPoint(&BlackXYZ, hProfile);
cmsTakeMediaWhitePoint(&MediaWhite, hProfile);
// Black point is absolute XYZ, so adapt to D50 to get PCS value
cmsAdaptToIlluminant(&UntrustedBlackPoint, &MediaWhite, cmsD50_XYZ(), &BlackXYZ);
// Force a=b=0 to get rid of any chroma
cmsXYZ2Lab(NULL, &Lab, &UntrustedBlackPoint);
Lab.a = Lab.b = 0;
if (Lab.L > 50) Lab.L = 50; // Clip to L* <= 50
cmsLab2XYZ(NULL, &TrustedBlackPoint, &Lab);
// Return BP as D50 relative or absolute XYZ (depends on flags)
if (!(dwFlags & LCMS_BPFLAGS_D50_ADAPTED))
cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &TrustedBlackPoint);
else
*BlackPoint = TrustedBlackPoint;
return 1;
}
#endif
// That is about v2 profiles.
// If output profile, discount ink-limiting and that's all
if (Intent == INTENT_RELATIVE_COLORIMETRIC &&
(cmsGetDeviceClass(hProfile) == icSigOutputClass) &&
(cmsGetColorSpace(hProfile) == icSigCmykData))
return BlackPointUsingPerceptualBlack(BlackPoint, hProfile, dwFlags);
// Nope, compute BP using current intent.
return BlackPointAsDarkerColorant(hProfile, Intent, BlackPoint, dwFlags);
}
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