--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/lcms2/src/cmsgmt.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,655 @@
+//---------------------------------------------------------------------------------
+//
+//  Little Color Management System
+//  Copyright (c) 1998-2021 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"
+
+
+// Auxiliary: append a Lab identity after the given sequence of profiles
+// and return the transform. Lab profile is closed, rest of profiles are kept open.
+cmsHTRANSFORM _cmsChain2Lab(cmsContext            ContextID,
+                            cmsUInt32Number        nProfiles,
+                            cmsUInt32Number        InputFormat,
+                            cmsUInt32Number        OutputFormat,
+                            const cmsUInt32Number  Intents[],
+                            const cmsHPROFILE      hProfiles[],
+                            const cmsBool          BPC[],
+                            const cmsFloat64Number AdaptationStates[],
+                            cmsUInt32Number        dwFlags)
+{
+    cmsHTRANSFORM xform;
+    cmsHPROFILE   hLab;
+    cmsHPROFILE   ProfileList[256];
+    cmsBool       BPCList[256];
+    cmsFloat64Number AdaptationList[256];
+    cmsUInt32Number IntentList[256];
+    cmsUInt32Number i;
+
+    // This is a rather big number and there is no need of dynamic memory
+    // since we are adding a profile, 254 + 1 = 255 and this is the limit
+    if (nProfiles > 254) return NULL;
+
+    // The output space
+    hLab = cmsCreateLab4Profile(ContextID, NULL);
+    if (hLab == NULL) return NULL;
+
+    // Create a copy of parameters
+    for (i=0; i < nProfiles; i++) {
+
+        ProfileList[i]    = hProfiles[i];
+        BPCList[i]        = BPC[i];
+        AdaptationList[i] = AdaptationStates[i];
+        IntentList[i]     = Intents[i];
+    }
+
+    // Place Lab identity at chain's end.
+    ProfileList[nProfiles]    = hLab;
+    BPCList[nProfiles]        = 0;
+    AdaptationList[nProfiles] = 1.0;
+    IntentList[nProfiles]     = INTENT_RELATIVE_COLORIMETRIC;
+
+    // Create the transform
+    xform = cmsCreateExtendedTransform(ContextID, nProfiles + 1, ProfileList,
+                                       BPCList,
+                                       IntentList,
+                                       AdaptationList,
+                                       NULL, 0,
+                                       InputFormat,
+                                       OutputFormat,
+                                       dwFlags);
+
+    cmsCloseProfile(ContextID, hLab);
+
+    return xform;
+}
+
+
+// Compute K -> L* relationship. Flags may include black point compensation. In this case,
+// the relationship is assumed from the profile with BPC to a black point zero.
+static
+cmsToneCurve* ComputeKToLstar(cmsContext            ContextID,
+                               cmsUInt32Number       nPoints,
+                               cmsUInt32Number       nProfiles,
+                               const cmsUInt32Number Intents[],
+                               const cmsHPROFILE     hProfiles[],
+                               const cmsBool         BPC[],
+                               const cmsFloat64Number AdaptationStates[],
+                               cmsUInt32Number dwFlags)
+{
+    cmsToneCurve* out = NULL;
+    cmsUInt32Number i;
+    cmsHTRANSFORM xform;
+    cmsCIELab Lab;
+    cmsFloat32Number cmyk[4];
+    cmsFloat32Number* SampledPoints;
+
+    xform = _cmsChain2Lab(ContextID, nProfiles, TYPE_CMYK_FLT, TYPE_Lab_DBL, Intents, hProfiles, BPC, AdaptationStates, dwFlags);
+    if (xform == NULL) return NULL;
+
+    SampledPoints = (cmsFloat32Number*) _cmsCalloc(ContextID, nPoints, sizeof(cmsFloat32Number));
+    if (SampledPoints  == NULL) goto Error;
+
+    for (i=0; i < nPoints; i++) {
+
+        cmyk[0] = 0;
+        cmyk[1] = 0;
+        cmyk[2] = 0;
+        cmyk[3] = (cmsFloat32Number) ((i * 100.0) / (nPoints-1));
+
+        cmsDoTransform(ContextID, xform, cmyk, &Lab, 1);
+        SampledPoints[i]= (cmsFloat32Number) (1.0 - Lab.L / 100.0); // Negate K for easier operation
+    }
+
+    out = cmsBuildTabulatedToneCurveFloat(ContextID, nPoints, SampledPoints);
+
+Error:
+
+    cmsDeleteTransform(ContextID, xform);
+    if (SampledPoints) _cmsFree(ContextID, SampledPoints);
+
+    return out;
+}
+
+
+// Compute Black tone curve on a CMYK -> CMYK transform. This is done by
+// using the proof direction on both profiles to find K->L* relationship
+// then joining both curves. dwFlags may include black point compensation.
+cmsToneCurve* _cmsBuildKToneCurve(cmsContext        ContextID,
+                                   cmsUInt32Number   nPoints,
+                                   cmsUInt32Number   nProfiles,
+                                   const cmsUInt32Number Intents[],
+                                   const cmsHPROFILE hProfiles[],
+                                   const cmsBool     BPC[],
+                                   const cmsFloat64Number AdaptationStates[],
+                                   cmsUInt32Number   dwFlags)
+{
+    cmsToneCurve *in, *out, *KTone;
+
+    // Make sure CMYK -> CMYK
+    if (cmsGetColorSpace(ContextID, hProfiles[0]) != cmsSigCmykData ||
+        cmsGetColorSpace(ContextID, hProfiles[nProfiles-1])!= cmsSigCmykData) return NULL;
+
+
+    // Make sure last is an output profile
+    if (cmsGetDeviceClass(ContextID, hProfiles[nProfiles - 1]) != cmsSigOutputClass) return NULL;
+
+    // Create individual curves. BPC works also as each K to L* is
+    // computed as a BPC to zero black point in case of L*
+    in  = ComputeKToLstar(ContextID, nPoints, nProfiles - 1, Intents, hProfiles, BPC, AdaptationStates, dwFlags);
+    if (in == NULL) return NULL;
+
+    out = ComputeKToLstar(ContextID, nPoints, 1,
+                            Intents + (nProfiles - 1),
+                            &hProfiles [nProfiles - 1],
+                            BPC + (nProfiles - 1),
+                            AdaptationStates + (nProfiles - 1),
+                            dwFlags);
+    if (out == NULL) {
+        cmsFreeToneCurve(ContextID, in);
+        return NULL;
+    }
+
+    // Build the relationship. This effectively limits the maximum accuracy to 16 bits, but
+    // since this is used on black-preserving LUTs, we are not losing  accuracy in any case
+    KTone = cmsJoinToneCurve(ContextID, in, out, nPoints);
+
+    // Get rid of components
+    cmsFreeToneCurve(ContextID, in); cmsFreeToneCurve(ContextID, out);
+
+    // Something went wrong...
+    if (KTone == NULL) return NULL;
+
+    // Make sure it is monotonic
+    if (!cmsIsToneCurveMonotonic(ContextID, KTone)) {
+        cmsFreeToneCurve(ContextID, KTone);
+        return NULL;
+    }
+
+    return KTone;
+}
+
+
+// Gamut LUT Creation -----------------------------------------------------------------------------------------
+
+// Used by gamut & softproofing
+
+typedef struct {
+
+    cmsHTRANSFORM hInput;               // From whatever input color space. 16 bits to DBL
+    cmsHTRANSFORM hForward, hReverse;   // Transforms going from Lab to colorant and back
+    cmsFloat64Number Threshold;         // The threshold after which is considered out of gamut
+
+    } GAMUTCHAIN;
+
+// This sampler does compute gamut boundaries by comparing original
+// values with a transform going back and forth. Values above ERR_THRESHOLD
+// of maximum are considered out of gamut.
+
+#define ERR_THRESHOLD      5
+
+
+static
+int GamutSampler(cmsContext ContextID, CMSREGISTER const cmsUInt16Number In[], CMSREGISTER cmsUInt16Number Out[], CMSREGISTER void* Cargo)
+{
+    GAMUTCHAIN*  t = (GAMUTCHAIN* ) Cargo;
+    cmsCIELab LabIn1, LabOut1;
+    cmsCIELab LabIn2, LabOut2;
+    cmsUInt16Number Proof[cmsMAXCHANNELS], Proof2[cmsMAXCHANNELS];
+    cmsFloat64Number dE1, dE2, ErrorRatio;
+
+    // Assume in-gamut by default. NEVER READ, USED FOR DEBUG PURPOSES.
+    ErrorRatio = 1.0;
+
+    // Convert input to Lab
+    cmsDoTransform(ContextID, t -> hInput, In, &LabIn1, 1);
+
+    // converts from PCS to colorant. This always
+    // does return in-gamut values,
+    cmsDoTransform(ContextID, t -> hForward, &LabIn1, Proof, 1);
+
+    // Now, do the inverse, from colorant to PCS.
+    cmsDoTransform(ContextID, t -> hReverse, Proof, &LabOut1, 1);
+
+    memmove(&LabIn2, &LabOut1, sizeof(cmsCIELab));
+
+    // Try again, but this time taking Check as input
+    cmsDoTransform(ContextID, t -> hForward, &LabOut1, Proof2, 1);
+    cmsDoTransform(ContextID, t -> hReverse, Proof2, &LabOut2, 1);
+
+    // Take difference of direct value
+    dE1 = cmsDeltaE(ContextID, &LabIn1, &LabOut1);
+
+    // Take difference of converted value
+    dE2 = cmsDeltaE(ContextID, &LabIn2, &LabOut2);
+
+
+    // if dE1 is small and dE2 is small, value is likely to be in gamut
+    if (dE1 < t->Threshold && dE2 < t->Threshold)
+        Out[0] = 0;
+    else {
+
+        // if dE1 is small and dE2 is big, undefined. Assume in gamut
+        if (dE1 < t->Threshold && dE2 > t->Threshold)
+            Out[0] = 0;
+        else
+            // dE1 is big and dE2 is small, clearly out of gamut
+            if (dE1 > t->Threshold && dE2 < t->Threshold)
+                Out[0] = (cmsUInt16Number) _cmsQuickFloor((dE1 - t->Threshold) + .5);
+            else  {
+
+                // dE1 is big and dE2 is also big, could be due to perceptual mapping
+                // so take error ratio
+                if (dE2 == 0.0)
+                    ErrorRatio = dE1;
+                else
+                    ErrorRatio = dE1 / dE2;
+
+                if (ErrorRatio > t->Threshold)
+                    Out[0] = (cmsUInt16Number)  _cmsQuickFloor((ErrorRatio - t->Threshold) + .5);
+                else
+                    Out[0] = 0;
+            }
+    }
+
+
+    return TRUE;
+}
+
+// Does compute a gamut LUT going back and forth across pcs -> relativ. colorimetric intent -> pcs
+// the dE obtained is then annotated on the LUT. Values truly out of gamut are clipped to dE = 0xFFFE
+// and values changed are supposed to be handled by any gamut remapping, so, are out of gamut as well.
+//
+// **WARNING: This algorithm does assume that gamut remapping algorithms does NOT move in-gamut colors,
+// of course, many perceptual and saturation intents does not work in such way, but relativ. ones should.
+
+cmsPipeline* _cmsCreateGamutCheckPipeline(cmsContext ContextID,
+                                          cmsHPROFILE hProfiles[],
+                                          cmsBool  BPC[],
+                                          cmsUInt32Number Intents[],
+                                          cmsFloat64Number AdaptationStates[],
+                                          cmsUInt32Number nGamutPCSposition,
+                                          cmsHPROFILE hGamut)
+{
+    cmsHPROFILE hLab;
+    cmsPipeline* Gamut;
+    cmsStage* CLUT;
+    cmsUInt32Number dwFormat;
+    GAMUTCHAIN Chain;
+    cmsUInt32Number nGridpoints;
+    cmsInt32Number nChannels;
+    cmsColorSpaceSignature ColorSpace;
+    cmsUInt32Number i;
+    cmsHPROFILE ProfileList[256];
+    cmsBool     BPCList[256];
+    cmsFloat64Number AdaptationList[256];
+    cmsUInt32Number IntentList[256];
+
+    memset(&Chain, 0, sizeof(GAMUTCHAIN));
+
+
+    if (nGamutPCSposition <= 0 || nGamutPCSposition > 255) {
+        cmsSignalError(ContextID, cmsERROR_RANGE, "Wrong position of PCS. 1..255 expected, %d found.", nGamutPCSposition);
+        return NULL;
+    }
+
+    hLab = cmsCreateLab4Profile(ContextID, NULL);
+    if (hLab == NULL) return NULL;
+
+
+    // The figure of merit. On matrix-shaper profiles, should be almost zero as
+    // the conversion is pretty exact. On LUT based profiles, different resolutions
+    // of input and output CLUT may result in differences.
+
+    if (cmsIsMatrixShaper(ContextID, hGamut)) {
+
+        Chain.Threshold = 1.0;
+    }
+    else {
+        Chain.Threshold = ERR_THRESHOLD;
+    }
+
+
+    // Create a copy of parameters
+    for (i=0; i < nGamutPCSposition; i++) {
+        ProfileList[i]    = hProfiles[i];
+        BPCList[i]        = BPC[i];
+        AdaptationList[i] = AdaptationStates[i];
+        IntentList[i]     = Intents[i];
+    }
+
+    // Fill Lab identity
+    ProfileList[nGamutPCSposition] = hLab;
+    BPCList[nGamutPCSposition] = 0;
+    AdaptationList[nGamutPCSposition] = 1.0;
+    IntentList[nGamutPCSposition] = INTENT_RELATIVE_COLORIMETRIC;
+
+
+    ColorSpace  = cmsGetColorSpace(ContextID, hGamut);
+    nChannels   = cmsChannelsOfColorSpace(ContextID, ColorSpace);
+    nGridpoints = _cmsReasonableGridpointsByColorspace(ContextID, ColorSpace, cmsFLAGS_HIGHRESPRECALC);
+    dwFormat    = (CHANNELS_SH(nChannels)|BYTES_SH(2));
+
+    // 16 bits to Lab double
+    Chain.hInput = cmsCreateExtendedTransform(ContextID,
+        nGamutPCSposition + 1,
+        ProfileList,
+        BPCList,
+        IntentList,
+        AdaptationList,
+        NULL, 0,
+        dwFormat, TYPE_Lab_DBL,
+        cmsFLAGS_NOCACHE);
+
+
+    // Does create the forward step. Lab double to device
+    dwFormat    = (CHANNELS_SH(nChannels)|BYTES_SH(2));
+    Chain.hForward = cmsCreateTransform(ContextID,
+        hLab, TYPE_Lab_DBL,
+        hGamut, dwFormat,
+        INTENT_RELATIVE_COLORIMETRIC,
+        cmsFLAGS_NOCACHE);
+
+    // Does create the backwards step
+    Chain.hReverse = cmsCreateTransform(ContextID, hGamut, dwFormat,
+        hLab, TYPE_Lab_DBL,
+        INTENT_RELATIVE_COLORIMETRIC,
+        cmsFLAGS_NOCACHE);
+
+
+    // All ok?
+    if (Chain.hInput && Chain.hForward && Chain.hReverse) {
+
+        // Go on, try to compute gamut LUT from PCS. This consist on a single channel containing
+        // dE when doing a transform back and forth on the colorimetric intent.
+
+        Gamut = cmsPipelineAlloc(ContextID, 3, 1);
+        if (Gamut != NULL) {
+
+            CLUT = cmsStageAllocCLut16bit(ContextID, nGridpoints, nChannels, 1, NULL);
+            if (!cmsPipelineInsertStage(ContextID, Gamut, cmsAT_BEGIN, CLUT)) {
+                cmsPipelineFree(ContextID, Gamut);
+                Gamut = NULL;
+            }
+            else {
+                cmsStageSampleCLut16bit(ContextID, CLUT, GamutSampler, (void*) &Chain, 0);
+            }
+        }
+    }
+    else
+        Gamut = NULL;   // Didn't work...
+
+    // Free all needed stuff.
+    if (Chain.hInput)   cmsDeleteTransform(ContextID, Chain.hInput);
+    if (Chain.hForward) cmsDeleteTransform(ContextID, Chain.hForward);
+    if (Chain.hReverse) cmsDeleteTransform(ContextID, Chain.hReverse);
+    if (hLab) cmsCloseProfile(ContextID, hLab);
+
+    // And return computed hull
+    return Gamut;
+}
+
+// Total Area Coverage estimation ----------------------------------------------------------------
+
+typedef struct {
+    cmsUInt32Number  nOutputChans;
+    cmsHTRANSFORM    hRoundTrip;
+    cmsFloat32Number MaxTAC;
+    cmsFloat32Number MaxInput[cmsMAXCHANNELS];
+
+} cmsTACestimator;
+
+
+// This callback just accounts the maximum ink dropped in the given node. It does not populate any
+// memory, as the destination table is NULL. Its only purpose it to know the global maximum.
+static
+int EstimateTAC(cmsContext ContextID, CMSREGISTER const cmsUInt16Number In[], CMSREGISTER cmsUInt16Number Out[], CMSREGISTER void * Cargo)
+{
+    cmsTACestimator* bp = (cmsTACestimator*) Cargo;
+    cmsFloat32Number RoundTrip[cmsMAXCHANNELS];
+    cmsUInt32Number i;
+    cmsFloat32Number Sum;
+
+
+    // Evaluate the xform
+    cmsDoTransform(ContextID, bp->hRoundTrip, In, RoundTrip, 1);
+
+    // All all amounts of ink
+    for (Sum=0, i=0; i < bp ->nOutputChans; i++)
+            Sum += RoundTrip[i];
+
+    // If above maximum, keep track of input values
+    if (Sum > bp ->MaxTAC) {
+
+            bp ->MaxTAC = Sum;
+
+            for (i=0; i < bp ->nOutputChans; i++) {
+                bp ->MaxInput[i] = In[i];
+            }
+    }
+
+    return TRUE;
+
+    cmsUNUSED_PARAMETER(Out);
+}
+
+
+// Detect Total area coverage of the profile
+cmsFloat64Number CMSEXPORT cmsDetectTAC(cmsContext ContextID, cmsHPROFILE hProfile)
+{
+    cmsTACestimator bp;
+    cmsUInt32Number dwFormatter;
+    cmsUInt32Number GridPoints[MAX_INPUT_DIMENSIONS];
+    cmsHPROFILE hLab;
+
+    // TAC only works on output profiles
+    if (cmsGetDeviceClass(ContextID, hProfile) != cmsSigOutputClass) {
+        return 0;
+    }
+
+    // Create a fake formatter for result
+    dwFormatter = cmsFormatterForColorspaceOfProfile(ContextID, hProfile, 4, TRUE);
+
+    // Unsupported color space?
+    if (dwFormatter == 0) return 0;
+
+    bp.nOutputChans = T_CHANNELS(dwFormatter);
+    bp.MaxTAC = 0;    // Initial TAC is 0
+
+    //  for safety
+    if (bp.nOutputChans >= cmsMAXCHANNELS) return 0;
+
+    hLab = cmsCreateLab4Profile(ContextID, NULL);
+    if (hLab == NULL) return 0;
+    // Setup a roundtrip on perceptual intent in output profile for TAC estimation
+    bp.hRoundTrip = cmsCreateTransform(ContextID, hLab, TYPE_Lab_16,
+                                          hProfile, dwFormatter, INTENT_PERCEPTUAL, cmsFLAGS_NOOPTIMIZE|cmsFLAGS_NOCACHE);
+
+    cmsCloseProfile(ContextID, hLab);
+    if (bp.hRoundTrip == NULL) return 0;
+
+    // For L* we only need black and white. For C* we need many points
+    GridPoints[0] = 6;
+    GridPoints[1] = 74;
+    GridPoints[2] = 74;
+
+
+    if (!cmsSliceSpace16(ContextID, 3, GridPoints, EstimateTAC, &bp)) {
+        bp.MaxTAC = 0;
+    }
+
+    cmsDeleteTransform(ContextID, bp.hRoundTrip);
+
+    // Results in %
+    return bp.MaxTAC;
+}
+
+
+// Carefully,  clamp on CIELab space.
+
+cmsBool CMSEXPORT cmsDesaturateLab(cmsContext ContextID, cmsCIELab* Lab,
+                                   double amax, double amin,
+                                   double bmax, double bmin)
+{
+
+    // Whole Luma surface to zero
+
+    if (Lab -> L < 0) {
+
+        Lab-> L = Lab->a = Lab-> b = 0.0;
+        return FALSE;
+    }
+
+    // Clamp white, DISCARD HIGHLIGHTS. This is done
+    // in such way because icc spec doesn't allow the
+    // use of L>100 as a highlight means.
+
+    if (Lab->L > 100)
+        Lab -> L = 100;
+
+    // Check out gamut prism, on a, b faces
+
+    if (Lab -> a < amin || Lab->a > amax||
+        Lab -> b < bmin || Lab->b > bmax) {
+
+            cmsCIELCh LCh;
+            double h, slope;
+
+            // Falls outside a, b limits. Transports to LCh space,
+            // and then do the clipping
+
+
+            if (Lab -> a == 0.0) { // Is hue exactly 90?
+
+                // atan will not work, so clamp here
+                Lab -> b = Lab->b < 0 ? bmin : bmax;
+                return TRUE;
+            }
+
+            cmsLab2LCh(ContextID, &LCh, Lab);
+
+            slope = Lab -> b / Lab -> a;
+            h = LCh.h;
+
+            // There are 4 zones
+
+            if ((h >= 0. && h < 45.) ||
+                (h >= 315 && h <= 360.)) {
+
+                    // clip by amax
+                    Lab -> a = amax;
+                    Lab -> b = amax * slope;
+            }
+            else
+                if (h >= 45. && h < 135.)
+                {
+                    // clip by bmax
+                    Lab -> b = bmax;
+                    Lab -> a = bmax / slope;
+                }
+                else
+                    if (h >= 135. && h < 225.) {
+                        // clip by amin
+                        Lab -> a = amin;
+                        Lab -> b = amin * slope;
+
+                    }
+                    else
+                        if (h >= 225. && h < 315.) {
+                            // clip by bmin
+                            Lab -> b = bmin;
+                            Lab -> a = bmin / slope;
+                        }
+                        else  {
+                            cmsSignalError(0, cmsERROR_RANGE, "Invalid angle");
+                            return FALSE;
+                        }
+
+    }
+
+    return TRUE;
+}
+
+// Detect whatever a given ICC profile works in linear (gamma 1.0) space
+// Actually, doing that "well" is quite hard, since every component may behave completely different.
+// Since the true point of this function is to detect suitable optimizations, I am imposing some requirements
+// that simplifies things: only RGB, and only profiles that can got in both directions.
+// The algorithm obtains Y from a synthetical gray R=G=B. Then least squares fitting is used to estimate gamma.
+// For gamma close to 1.0, RGB is linear. On profiles not supported, -1 is returned.
+
+cmsFloat64Number CMSEXPORT cmsDetectRGBProfileGamma(cmsContext ContextID, cmsHPROFILE hProfile, cmsFloat64Number threshold)
+{
+    cmsHPROFILE hXYZ;
+    cmsHTRANSFORM xform;
+    cmsToneCurve* Y_curve;
+    cmsUInt16Number rgb[256][3];
+    cmsCIEXYZ XYZ[256];
+    cmsFloat32Number Y_normalized[256];
+    cmsFloat64Number gamma;
+    cmsProfileClassSignature cl;
+    int i;
+
+    if (cmsGetColorSpace(ContextID, hProfile) != cmsSigRgbData)
+        return -1;
+
+    cl = cmsGetDeviceClass(ContextID, hProfile);
+    if (cl != cmsSigInputClass && cl != cmsSigDisplayClass &&
+        cl != cmsSigOutputClass && cl != cmsSigColorSpaceClass)
+        return -1;
+
+    hXYZ = cmsCreateXYZProfile(ContextID);
+    if (hXYZ == NULL)
+        return -1;
+    xform = cmsCreateTransform(ContextID, hProfile, TYPE_RGB_16, hXYZ, TYPE_XYZ_DBL,
+                                    INTENT_RELATIVE_COLORIMETRIC, cmsFLAGS_NOOPTIMIZE);
+
+    if (xform == NULL) { // If not RGB or forward direction is not supported, regret with the previous error
+
+        cmsCloseProfile(ContextID, hXYZ);
+        return -1;
+    }
+
+    for (i = 0; i < 256; i++) {
+        rgb[i][0] = rgb[i][1] = rgb[i][2] = FROM_8_TO_16(i);
+    }
+
+    cmsDoTransform(ContextID, xform, rgb, XYZ, 256);
+
+    cmsDeleteTransform(ContextID, xform);
+    cmsCloseProfile(ContextID, hXYZ);
+
+    for (i = 0; i < 256; i++) {
+        Y_normalized[i] = (cmsFloat32Number) XYZ[i].Y;
+    }
+
+    Y_curve = cmsBuildTabulatedToneCurveFloat(ContextID, 256, Y_normalized);
+    if (Y_curve == NULL)
+        return -1;
+
+    gamma = cmsEstimateGamma(ContextID, Y_curve, threshold);
+
+    cmsFreeToneCurve(ContextID, Y_curve);
+
+    return gamma;
+}