//---------------------------------------------------------------------------------
//
// Little Color Management System
// Copyright (c) 1998-2016 Marti Maria Saguer
//
// 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 "lcms2_internal.h"
// CIECAM 02 appearance model. Many thanks to Jordi Vilar for the debugging.
// ---------- Implementation --------------------------------------------
typedef struct {
cmsFloat64Number XYZ[3];
cmsFloat64Number RGB[3];
cmsFloat64Number RGBc[3];
cmsFloat64Number RGBp[3];
cmsFloat64Number RGBpa[3];
cmsFloat64Number a, b, h, e, H, A, J, Q, s, t, C, M;
cmsFloat64Number abC[2];
cmsFloat64Number abs[2];
cmsFloat64Number abM[2];
} CAM02COLOR;
typedef struct {
CAM02COLOR adoptedWhite;
cmsFloat64Number LA, Yb;
cmsFloat64Number F, c, Nc;
cmsUInt32Number surround;
cmsFloat64Number n, Nbb, Ncb, z, FL, D;
cmsContext ContextID;
} cmsCIECAM02;
static
cmsFloat64Number compute_n(cmsCIECAM02* pMod)
{
return (pMod -> Yb / pMod -> adoptedWhite.XYZ[1]);
}
static
cmsFloat64Number compute_z(cmsCIECAM02* pMod)
{
return (1.48 + pow(pMod -> n, 0.5));
}
static
cmsFloat64Number computeNbb(cmsCIECAM02* pMod)
{
return (0.725 * pow((1.0 / pMod -> n), 0.2));
}
static
cmsFloat64Number computeFL(cmsCIECAM02* pMod)
{
cmsFloat64Number k, FL;
k = 1.0 / ((5.0 * pMod->LA) + 1.0);
FL = 0.2 * pow(k, 4.0) * (5.0 * pMod->LA) + 0.1 *
(pow((1.0 - pow(k, 4.0)), 2.0)) *
(pow((5.0 * pMod->LA), (1.0 / 3.0)));
return FL;
}
static
cmsFloat64Number computeD(cmsCIECAM02* pMod)
{
cmsFloat64Number D;
D = pMod->F - (1.0/3.6)*(exp(((-pMod ->LA-42) / 92.0)));
return D;
}
static
CAM02COLOR XYZtoCAT02(CAM02COLOR clr)
{
clr.RGB[0] = (clr.XYZ[0] * 0.7328) + (clr.XYZ[1] * 0.4296) + (clr.XYZ[2] * -0.1624);
clr.RGB[1] = (clr.XYZ[0] * -0.7036) + (clr.XYZ[1] * 1.6975) + (clr.XYZ[2] * 0.0061);
clr.RGB[2] = (clr.XYZ[0] * 0.0030) + (clr.XYZ[1] * 0.0136) + (clr.XYZ[2] * 0.9834);
return clr;
}
static
CAM02COLOR ChromaticAdaptation(CAM02COLOR clr, cmsCIECAM02* pMod)
{
cmsUInt32Number i;
for (i = 0; i < 3; i++) {
clr.RGBc[i] = ((pMod -> adoptedWhite.XYZ[1] *
(pMod->D / pMod -> adoptedWhite.RGB[i])) +
(1.0 - pMod->D)) * clr.RGB[i];
}
return clr;
}
static
CAM02COLOR CAT02toHPE(CAM02COLOR clr)
{
cmsFloat64Number M[9];
M[0] =(( 0.38971 * 1.096124) + (0.68898 * 0.454369) + (-0.07868 * -0.009628));
M[1] =(( 0.38971 * -0.278869) + (0.68898 * 0.473533) + (-0.07868 * -0.005698));
M[2] =(( 0.38971 * 0.182745) + (0.68898 * 0.072098) + (-0.07868 * 1.015326));
M[3] =((-0.22981 * 1.096124) + (1.18340 * 0.454369) + ( 0.04641 * -0.009628));
M[4] =((-0.22981 * -0.278869) + (1.18340 * 0.473533) + ( 0.04641 * -0.005698));
M[5] =((-0.22981 * 0.182745) + (1.18340 * 0.072098) + ( 0.04641 * 1.015326));
M[6] =(-0.009628);
M[7] =(-0.005698);
M[8] =( 1.015326);
clr.RGBp[0] = (clr.RGBc[0] * M[0]) + (clr.RGBc[1] * M[1]) + (clr.RGBc[2] * M[2]);
clr.RGBp[1] = (clr.RGBc[0] * M[3]) + (clr.RGBc[1] * M[4]) + (clr.RGBc[2] * M[5]);
clr.RGBp[2] = (clr.RGBc[0] * M[6]) + (clr.RGBc[1] * M[7]) + (clr.RGBc[2] * M[8]);
return clr;
}
static
CAM02COLOR NonlinearCompression(CAM02COLOR clr, cmsCIECAM02* pMod)
{
cmsUInt32Number i;
cmsFloat64Number temp;
for (i = 0; i < 3; i++) {
if (clr.RGBp[i] < 0) {
temp = pow((-1.0 * pMod->FL * clr.RGBp[i] / 100.0), 0.42);
clr.RGBpa[i] = (-1.0 * 400.0 * temp) / (temp + 27.13) + 0.1;
}
else {
temp = pow((pMod->FL * clr.RGBp[i] / 100.0), 0.42);
clr.RGBpa[i] = (400.0 * temp) / (temp + 27.13) + 0.1;
}
}
clr.A = (((2.0 * clr.RGBpa[0]) + clr.RGBpa[1] +
(clr.RGBpa[2] / 20.0)) - 0.305) * pMod->Nbb;
return clr;
}
static
CAM02COLOR ComputeCorrelates(CAM02COLOR clr, cmsCIECAM02* pMod)
{
cmsFloat64Number a, b, temp, e, t, r2d, d2r;
a = clr.RGBpa[0] - (12.0 * clr.RGBpa[1] / 11.0) + (clr.RGBpa[2] / 11.0);
b = (clr.RGBpa[0] + clr.RGBpa[1] - (2.0 * clr.RGBpa[2])) / 9.0;
r2d = (180.0 / 3.141592654);
if (a == 0) {
if (b == 0) clr.h = 0;
else if (b > 0) clr.h = 90;
else clr.h = 270;
}
else if (a > 0) {
temp = b / a;
if (b > 0) clr.h = (r2d * atan(temp));
else if (b == 0) clr.h = 0;
else clr.h = (r2d * atan(temp)) + 360;
}
else {
temp = b / a;
clr.h = (r2d * atan(temp)) + 180;
}
d2r = (3.141592654 / 180.0);
e = ((12500.0 / 13.0) * pMod->Nc * pMod->Ncb) *
(cos((clr.h * d2r + 2.0)) + 3.8);
if (clr.h < 20.14) {
temp = ((clr.h + 122.47)/1.2) + ((20.14 - clr.h)/0.8);
clr.H = 300 + (100*((clr.h + 122.47)/1.2)) / temp;
}
else if (clr.h < 90.0) {
temp = ((clr.h - 20.14)/0.8) + ((90.00 - clr.h)/0.7);
clr.H = (100*((clr.h - 20.14)/0.8)) / temp;
}
else if (clr.h < 164.25) {
temp = ((clr.h - 90.00)/0.7) + ((164.25 - clr.h)/1.0);
clr.H = 100 + ((100*((clr.h - 90.00)/0.7)) / temp);
}
else if (clr.h < 237.53) {
temp = ((clr.h - 164.25)/1.0) + ((237.53 - clr.h)/1.2);
clr.H = 200 + ((100*((clr.h - 164.25)/1.0)) / temp);
}
else {
temp = ((clr.h - 237.53)/1.2) + ((360 - clr.h + 20.14)/0.8);
clr.H = 300 + ((100*((clr.h - 237.53)/1.2)) / temp);
}
clr.J = 100.0 * pow((clr.A / pMod->adoptedWhite.A),
(pMod->c * pMod->z));
clr.Q = (4.0 / pMod->c) * pow((clr.J / 100.0), 0.5) *
(pMod->adoptedWhite.A + 4.0) * pow(pMod->FL, 0.25);
t = (e * pow(((a * a) + (b * b)), 0.5)) /
(clr.RGBpa[0] + clr.RGBpa[1] +
((21.0 / 20.0) * clr.RGBpa[2]));
clr.C = pow(t, 0.9) * pow((clr.J / 100.0), 0.5) *
pow((1.64 - pow(0.29, pMod->n)), 0.73);
clr.M = clr.C * pow(pMod->FL, 0.25);
clr.s = 100.0 * pow((clr.M / clr.Q), 0.5);
return clr;
}
static
CAM02COLOR InverseCorrelates(CAM02COLOR clr, cmsCIECAM02* pMod)
{
cmsFloat64Number t, e, p1, p2, p3, p4, p5, hr, d2r;
d2r = 3.141592654 / 180.0;
t = pow( (clr.C / (pow((clr.J / 100.0), 0.5) *
(pow((1.64 - pow(0.29, pMod->n)), 0.73)))),
(1.0 / 0.9) );
e = ((12500.0 / 13.0) * pMod->Nc * pMod->Ncb) *
(cos((clr.h * d2r + 2.0)) + 3.8);
clr.A = pMod->adoptedWhite.A * pow(
(clr.J / 100.0),
(1.0 / (pMod->c * pMod->z)));
p1 = e / t;
p2 = (clr.A / pMod->Nbb) + 0.305;
p3 = 21.0 / 20.0;
hr = clr.h * d2r;
if (fabs(sin(hr)) >= fabs(cos(hr))) {
p4 = p1 / sin(hr);
clr.b = (p2 * (2.0 + p3) * (460.0 / 1403.0)) /
(p4 + (2.0 + p3) * (220.0 / 1403.0) *
(cos(hr) / sin(hr)) - (27.0 / 1403.0) +
p3 * (6300.0 / 1403.0));
clr.a = clr.b * (cos(hr) / sin(hr));
}
else {
p5 = p1 / cos(hr);
clr.a = (p2 * (2.0 + p3) * (460.0 / 1403.0)) /
(p5 + (2.0 + p3) * (220.0 / 1403.0) -
((27.0 / 1403.0) - p3 * (6300.0 / 1403.0)) *
(sin(hr) / cos(hr)));
clr.b = clr.a * (sin(hr) / cos(hr));
}
clr.RGBpa[0] = ((460.0 / 1403.0) * p2) +
((451.0 / 1403.0) * clr.a) +
((288.0 / 1403.0) * clr.b);
clr.RGBpa[1] = ((460.0 / 1403.0) * p2) -
((891.0 / 1403.0) * clr.a) -
((261.0 / 1403.0) * clr.b);
clr.RGBpa[2] = ((460.0 / 1403.0) * p2) -
((220.0 / 1403.0) * clr.a) -
((6300.0 / 1403.0) * clr.b);
return clr;
}
static
CAM02COLOR InverseNonlinearity(CAM02COLOR clr, cmsCIECAM02* pMod)
{
cmsUInt32Number i;
cmsFloat64Number c1;
for (i = 0; i < 3; i++) {
if ((clr.RGBpa[i] - 0.1) < 0) c1 = -1;
else c1 = 1;
clr.RGBp[i] = c1 * (100.0 / pMod->FL) *
pow(((27.13 * fabs(clr.RGBpa[i] - 0.1)) /
(400.0 - fabs(clr.RGBpa[i] - 0.1))),
(1.0 / 0.42));
}
return clr;
}
static
CAM02COLOR HPEtoCAT02(CAM02COLOR clr)
{
cmsFloat64Number M[9];
M[0] = (( 0.7328 * 1.910197) + (0.4296 * 0.370950));
M[1] = (( 0.7328 * -1.112124) + (0.4296 * 0.629054));
M[2] = (( 0.7328 * 0.201908) + (0.4296 * 0.000008) - 0.1624);
M[3] = ((-0.7036 * 1.910197) + (1.6975 * 0.370950));
M[4] = ((-0.7036 * -1.112124) + (1.6975 * 0.629054));
M[5] = ((-0.7036 * 0.201908) + (1.6975 * 0.000008) + 0.0061);
M[6] = (( 0.0030 * 1.910197) + (0.0136 * 0.370950));
M[7] = (( 0.0030 * -1.112124) + (0.0136 * 0.629054));
M[8] = (( 0.0030 * 0.201908) + (0.0136 * 0.000008) + 0.9834);;
clr.RGBc[0] = (clr.RGBp[0] * M[0]) + (clr.RGBp[1] * M[1]) + (clr.RGBp[2] * M[2]);
clr.RGBc[1] = (clr.RGBp[0] * M[3]) + (clr.RGBp[1] * M[4]) + (clr.RGBp[2] * M[5]);
clr.RGBc[2] = (clr.RGBp[0] * M[6]) + (clr.RGBp[1] * M[7]) + (clr.RGBp[2] * M[8]);
return clr;
}
static
CAM02COLOR InverseChromaticAdaptation(CAM02COLOR clr, cmsCIECAM02* pMod)
{
cmsUInt32Number i;
for (i = 0; i < 3; i++) {
clr.RGB[i] = clr.RGBc[i] /
((pMod->adoptedWhite.XYZ[1] * pMod->D / pMod->adoptedWhite.RGB[i]) + 1.0 - pMod->D);
}
return clr;
}
static
CAM02COLOR CAT02toXYZ(CAM02COLOR clr)
{
clr.XYZ[0] = (clr.RGB[0] * 1.096124) + (clr.RGB[1] * -0.278869) + (clr.RGB[2] * 0.182745);
clr.XYZ[1] = (clr.RGB[0] * 0.454369) + (clr.RGB[1] * 0.473533) + (clr.RGB[2] * 0.072098);
clr.XYZ[2] = (clr.RGB[0] * -0.009628) + (clr.RGB[1] * -0.005698) + (clr.RGB[2] * 1.015326);
return clr;
}
cmsHANDLE CMSEXPORT cmsCIECAM02Init(cmsContext ContextID, const cmsViewingConditions* pVC)
{
cmsCIECAM02* lpMod;
_cmsAssert(pVC != NULL);
if((lpMod = (cmsCIECAM02*) _cmsMallocZero(ContextID, sizeof(cmsCIECAM02))) == NULL) {
return NULL;
}
lpMod ->ContextID = ContextID;
lpMod ->adoptedWhite.XYZ[0] = pVC ->whitePoint.X;
lpMod ->adoptedWhite.XYZ[1] = pVC ->whitePoint.Y;
lpMod ->adoptedWhite.XYZ[2] = pVC ->whitePoint.Z;
lpMod -> LA = pVC ->La;
lpMod -> Yb = pVC ->Yb;
lpMod -> D = pVC ->D_value;
lpMod -> surround = pVC ->surround;
switch (lpMod -> surround) {
case CUTSHEET_SURROUND:
lpMod->F = 0.8;
lpMod->c = 0.41;
lpMod->Nc = 0.8;
break;
case DARK_SURROUND:
lpMod -> F = 0.8;
lpMod -> c = 0.525;
lpMod -> Nc = 0.8;
break;
case DIM_SURROUND:
lpMod -> F = 0.9;
lpMod -> c = 0.59;
lpMod -> Nc = 0.95;
break;
default:
// Average surround
lpMod -> F = 1.0;
lpMod -> c = 0.69;
lpMod -> Nc = 1.0;
}
lpMod -> n = compute_n(lpMod);
lpMod -> z = compute_z(lpMod);
lpMod -> Nbb = computeNbb(lpMod);
lpMod -> FL = computeFL(lpMod);
if (lpMod -> D == D_CALCULATE) {
lpMod -> D = computeD(lpMod);
}
lpMod -> Ncb = lpMod -> Nbb;
lpMod -> adoptedWhite = XYZtoCAT02(lpMod -> adoptedWhite);
lpMod -> adoptedWhite = ChromaticAdaptation(lpMod -> adoptedWhite, lpMod);
lpMod -> adoptedWhite = CAT02toHPE(lpMod -> adoptedWhite);
lpMod -> adoptedWhite = NonlinearCompression(lpMod -> adoptedWhite, lpMod);
return (cmsHANDLE) lpMod;
}
void CMSEXPORT cmsCIECAM02Done(cmsHANDLE hModel)
{
cmsCIECAM02* lpMod = (cmsCIECAM02*) hModel;
if (lpMod) _cmsFree(lpMod ->ContextID, lpMod);
}
void CMSEXPORT cmsCIECAM02Forward(cmsHANDLE hModel, const cmsCIEXYZ* pIn, cmsJCh* pOut)
{
CAM02COLOR clr;
cmsCIECAM02* lpMod = (cmsCIECAM02*) hModel;
_cmsAssert(lpMod != NULL);
_cmsAssert(pIn != NULL);
_cmsAssert(pOut != NULL);
memset(&clr, 0, sizeof(clr));
clr.XYZ[0] = pIn ->X;
clr.XYZ[1] = pIn ->Y;
clr.XYZ[2] = pIn ->Z;
clr = XYZtoCAT02(clr);
clr = ChromaticAdaptation(clr, lpMod);
clr = CAT02toHPE(clr);
clr = NonlinearCompression(clr, lpMod);
clr = ComputeCorrelates(clr, lpMod);
pOut ->J = clr.J;
pOut ->C = clr.C;
pOut ->h = clr.h;
}
void CMSEXPORT cmsCIECAM02Reverse(cmsHANDLE hModel, const cmsJCh* pIn, cmsCIEXYZ* pOut)
{
CAM02COLOR clr;
cmsCIECAM02* lpMod = (cmsCIECAM02*) hModel;
_cmsAssert(lpMod != NULL);
_cmsAssert(pIn != NULL);
_cmsAssert(pOut != NULL);
memset(&clr, 0, sizeof(clr));
clr.J = pIn -> J;
clr.C = pIn -> C;
clr.h = pIn -> h;
clr = InverseCorrelates(clr, lpMod);
clr = InverseNonlinearity(clr, lpMod);
clr = HPEtoCAT02(clr);
clr = InverseChromaticAdaptation(clr, lpMod);
clr = CAT02toXYZ(clr);
pOut ->X = clr.XYZ[0];
pOut ->Y = clr.XYZ[1];
pOut ->Z = clr.XYZ[2];
}