initial commit

1 files changed, 1136 insertions, 0 deletions

diff --git a/src/cmsgamma.c b/src/cmsgamma.c
new file mode 100644
index 0000000..8f8146d
--- /dev/null
+++ b/src/cmsgamma.c
@@ -0,0 +1,1136 @@
+//---------------------------------------------------------------------------------
+//
+//  Little Color Management System
+//  Copyright (c) 1998-2010 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"
+
+// Tone curves are powerful constructs that can contain curves specified in diverse ways. 
+// The curve is stored in segments, where each segment can be sampled or specified by parameters.
+// a 16.bit simplification of the *whole* curve is kept for optimization purposes. For float operation, 
+// each segment is evaluated separately. Plug-ins may be used to define new parametric schemes, 
+// each plug-in may define up to MAX_TYPES_IN_LCMS_PLUGIN functions types. For defining a function, 
+// the plug-in should provide the type id, how many parameters each type has, and a pointer to
+// a procedure that evaluates the function. In the case of reverse evaluation, the evaluator will 
+// be called with the type id as a negative value, and a sampled version of the reversed curve 
+// will be built.
+
+// ----------------------------------------------------------------- Implementation
+// Maxim number of nodes 
+#define MAX_NODES_IN_CURVE   4097
+#define MINUS_INF            (-1E22F)
+#define PLUS_INF             (+1E22F)
+
+// The list of supported parametric curves
+typedef struct _cmsParametricCurvesCollection_st {
+
+    int nFunctions;                                     // Number of supported functions in this chunk
+    int FunctionTypes[MAX_TYPES_IN_LCMS_PLUGIN];        // The identification types
+    int ParameterCount[MAX_TYPES_IN_LCMS_PLUGIN];       // Number of parameters for each function
+    cmsParametricCurveEvaluator    Evaluator;           // The evaluator
+
+    struct _cmsParametricCurvesCollection_st* Next; // Next in list
+
+} _cmsParametricCurvesCollection;
+
+
+// This is the default (built-in) evaluator 
+static cmsFloat64Number DefaultEvalParametricFn(cmsInt32Number Type, const cmsFloat64Number Params[], cmsFloat64Number R);
+
+// The built-in list
+static _cmsParametricCurvesCollection DefaultCurves = { 
+    9,                                  // # of curve types
+    { 1, 2, 3, 4, 5, 6, 7, 8, 108 },    // Parametric curve ID
+    { 1, 3, 4, 5, 7, 4, 5, 5, 1 },      // Parameters by type
+    DefaultEvalParametricFn,            // Evaluator
+    NULL                                // Next in chain
+};
+
+// The linked list head
+static _cmsParametricCurvesCollection* ParametricCurves = &DefaultCurves;
+
+// As a way to install new parametric curves
+cmsBool _cmsRegisterParametricCurvesPlugin(cmsPluginBase* Data)
+{
+    cmsPluginParametricCurves* Plugin = (cmsPluginParametricCurves*) Data;
+    _cmsParametricCurvesCollection* fl;
+    
+    if (Data == NULL) {
+    
+          ParametricCurves =  &DefaultCurves;
+          return TRUE;
+    }
+
+    fl = (_cmsParametricCurvesCollection*) _cmsPluginMalloc(sizeof(_cmsParametricCurvesCollection));
+    if (fl == NULL) return FALSE;
+
+    // Copy the parameters
+    fl ->Evaluator  = Plugin ->Evaluator;
+    fl ->nFunctions = Plugin ->nFunctions;
+
+    // Make sure no mem overwrites
+    if (fl ->nFunctions > MAX_TYPES_IN_LCMS_PLUGIN)
+        fl ->nFunctions = MAX_TYPES_IN_LCMS_PLUGIN;
+
+    // Copy the data
+    memmove(fl->FunctionTypes,  Plugin ->FunctionTypes,   fl->nFunctions * sizeof(cmsUInt32Number));
+    memmove(fl->ParameterCount, Plugin ->ParameterCount,  fl->nFunctions * sizeof(cmsUInt32Number));
+
+    // Keep linked list
+    fl ->Next = ParametricCurves;
+    ParametricCurves = fl;
+
+    // All is ok
+    return TRUE;
+}
+
+
+// Search in type list, return position or -1 if not found
+static
+int IsInSet(int Type, _cmsParametricCurvesCollection* c)
+{
+    int i;
+
+    for (i=0; i < c ->nFunctions; i++)
+        if (abs(Type) == c ->FunctionTypes[i]) return i;
+
+    return -1;
+}
+
+
+// Search for the collection which contains a specific type
+static
+_cmsParametricCurvesCollection *GetParametricCurveByType(int Type, int* index)
+{
+    _cmsParametricCurvesCollection* c;
+    int Position;
+
+    for (c = ParametricCurves; c != NULL; c = c ->Next) {
+
+        Position = IsInSet(Type, c);
+
+        if (Position != -1) {
+            if (index != NULL) 
+                *index = Position;
+            return c;
+        }
+    }
+
+    return NULL;
+}
+
+// Low level allocate, which takes care of memory details. nEntries may be zero, and in this case 
+// no optimation curve is computed. nSegments may also be zero in the inverse case, where only the
+// optimization curve is given. Both features simultaneously is an error
+static
+cmsToneCurve* AllocateToneCurveStruct(cmsContext ContextID, cmsInt32Number nEntries, 
+                                      cmsInt32Number nSegments, const cmsCurveSegment* Segments, 
+                                      const cmsUInt16Number* Values)
+{
+    cmsToneCurve* p;
+    int i;
+
+    // We allow huge tables, which are then restricted for smoothing operations
+    if (nEntries > 65530 || nEntries < 0) {
+        cmsSignalError(ContextID, cmsERROR_RANGE, "Couldn't create tone curve of more than 65530 entries");
+        return NULL;
+    }
+
+    if (nEntries <= 0 && nSegments <= 0) {
+        cmsSignalError(ContextID, cmsERROR_RANGE, "Couldn't create tone curve with zero segments and no table");
+        return NULL;
+    }
+
+    // Allocate all required pointers, etc.
+    p = (cmsToneCurve*) _cmsMallocZero(ContextID, sizeof(cmsToneCurve));
+    if (!p) return NULL;
+
+    // In this case, there are no segments
+    if (nSegments <= 0) {
+        p ->Segments = NULL;
+        p ->Evals = NULL;
+    }
+    else {
+        p ->Segments = (cmsCurveSegment*) _cmsCalloc(ContextID, nSegments, sizeof(cmsCurveSegment));
+        if (p ->Segments == NULL) goto Error;
+
+        p ->Evals    = (cmsParametricCurveEvaluator*) _cmsCalloc(ContextID, nSegments, sizeof(cmsParametricCurveEvaluator));
+        if (p ->Evals == NULL) goto Error;
+    }
+
+    p -> nSegments = nSegments;
+    
+    // This 16-bit table contains a limited precision representation of the whole curve and is kept for
+    // increasing xput on certain operations.
+    if (nEntries <= 0) {
+        p ->Table16 = NULL;
+    }
+    else {
+       p ->Table16 = (cmsUInt16Number*)  _cmsCalloc(ContextID, nEntries, sizeof(cmsUInt16Number));
+       if (p ->Table16 == NULL) goto Error;
+    }
+   
+    p -> nEntries  = nEntries;
+    
+    // Initialize members if requested
+    if (Values != NULL && (nEntries > 0)) {
+
+        for (i=0; i < nEntries; i++) 
+            p ->Table16[i] = Values[i];
+    }
+
+    // Initialize the segments stuff. The evaluator for each segment is located and a pointer to it
+    // is placed in advance to maximize performance.
+    if (Segments != NULL && (nSegments > 0)) {
+
+        _cmsParametricCurvesCollection *c;
+
+        p ->SegInterp = (cmsInterpParams**) _cmsCalloc(ContextID, nSegments, sizeof(cmsInterpParams*));
+        if (p ->SegInterp == NULL) goto Error;
+
+        for (i=0; i< nSegments; i++) {
+
+            // Type 0 is a special marker for table-based curves
+            if (Segments[i].Type == 0)
+                p ->SegInterp[i] = _cmsComputeInterpParams(ContextID, Segments[i].nGridPoints, 1, 1, NULL, CMS_LERP_FLAGS_FLOAT);
+
+            memmove(&p ->Segments[i], &Segments[i], sizeof(cmsCurveSegment));
+
+            if (Segments[i].Type == 0 && Segments[i].SampledPoints != NULL)
+                p ->Segments[i].SampledPoints = (cmsFloat32Number*) _cmsDupMem(ContextID, Segments[i].SampledPoints, sizeof(cmsFloat32Number) * Segments[i].nGridPoints);
+            else
+                p ->Segments[i].SampledPoints = NULL;
+
+
+            c = GetParametricCurveByType(Segments[i].Type, NULL);
+            if (c != NULL)
+                    p ->Evals[i] = c ->Evaluator;
+        }
+    }
+    
+    p ->InterpParams = _cmsComputeInterpParams(ContextID, p ->nEntries, 1, 1, p->Table16, CMS_LERP_FLAGS_16BITS);
+    return p;
+
+Error:
+    if (p -> Segments) _cmsFree(ContextID, p ->Segments);
+    if (p -> Evals) _cmsFree(ContextID, p -> Evals);
+    if (p ->Table16) _cmsFree(ContextID, p ->Table16);
+    _cmsFree(ContextID, p);
+    return NULL;
+}
+
+
+// Parametric Fn using floating point
+static
+cmsFloat64Number DefaultEvalParametricFn(cmsInt32Number Type, const cmsFloat64Number Params[], cmsFloat64Number R)
+{
+    cmsFloat64Number e, Val, disc;
+
+    switch (Type) {
+
+    // X = Y ^ Gamma
+    case 1:
+        if (R < 0) 
+            Val = 0;
+        else
+            Val = pow(R, Params[0]);
+        break;
+
+    // Type 1 Reversed: X = Y ^1/gamma
+    case -1:
+        if (R < 0)
+            Val = 0;
+        else
+            Val = pow(R, 1/Params[0]);
+        break;
+
+    // CIE 122-1966
+    // Y = (aX + b)^Gamma  | X >= -b/a
+    // Y = 0               | else
+    case 2:
+        disc = -Params[2] / Params[1];
+
+        if (R >= disc ) {
+
+            e = Params[1]*R + Params[2];
+
+            if (e > 0)
+                Val = pow(e, Params[0]);
+            else
+                Val = 0;
+        }
+        else
+            Val = 0;
+        break;
+
+     // Type 2 Reversed
+     // X = (Y ^1/g  - b) / a
+     case -2: 
+         if (R < 0)
+             Val = 0;
+         else
+             Val = (pow(R, 1.0/Params[0]) - Params[2]) / Params[1];
+
+         if (Val < 0)
+              Val = 0;                            
+         break;
+
+
+    // IEC 61966-3
+    // Y = (aX + b)^Gamma | X <= -b/a
+    // Y = c              | else
+    case 3:
+        disc = -Params[2] / Params[1];
+        if (disc < 0)
+            disc = 0;
+
+        if (R >= disc) {
+
+            e = Params[1]*R + Params[2];  
+
+            if (e > 0)
+                Val = pow(e, Params[0]) + Params[3];
+            else
+                Val = 0;
+        }
+        else
+            Val = Params[3];
+        break;
+
+
+    // Type 3 reversed
+    // X=((Y-c)^1/g - b)/a      | (Y>=c)
+    // X=-b/a                   | (Y<c) 
+    case -3:
+        if (R >= Params[3])  {
+            
+            e = R - Params[3];
+
+            if (e > 0)
+                Val = (pow(e, 1/Params[0]) - Params[2]) / Params[1];
+            else 
+                Val = 0;
+        }
+        else {
+            Val = -Params[2] / Params[1];
+        }
+        break;
+
+
+    // IEC 61966-2.1 (sRGB)
+    // Y = (aX + b)^Gamma | X >= d
+    // Y = cX             | X < d
+    case 4:
+        if (R >= Params[4]) {
+
+            e = Params[1]*R + Params[2];
+
+            if (e > 0)
+                Val = pow(e, Params[0]);
+            else
+                Val = 0;
+        }
+        else
+            Val = R * Params[3];
+        break;
+
+    // Type 4 reversed
+    // X=((Y^1/g-b)/a)    | Y >= (ad+b)^g
+    // X=Y/c              | Y< (ad+b)^g
+    case -4:
+        e = Params[1] * Params[4] + Params[2];
+        if (e < 0)
+            disc = 0;
+        else
+            disc = pow(e, Params[0]);
+
+        if (R >= disc) {
+
+            Val = (pow(R, 1.0/Params[0]) - Params[2]) / Params[1];
+        }
+        else {
+            Val = R / Params[3];
+        }
+        break;
+
+
+    // Y = (aX + b)^Gamma + e | X >= d
+    // Y = cX + f             | X < d
+    case 5:
+        if (R >= Params[4]) {
+
+            e = Params[1]*R + Params[2];
+
+            if (e > 0)
+                Val = pow(e, Params[0]) + Params[5];
+            else
+                Val = 0;
+        }        
+        else
+            Val = R*Params[3] + Params[6];
+        break;
+
+
+    // Reversed type 5
+    // X=((Y-e)1/g-b)/a   | Y >=(ad+b)^g+e), cd+f
+    // X=(Y-f)/c          | else
+    case -5:
+
+        disc = Params[3] * Params[4] + Params[6];
+        if (R >= disc) {
+
+            e = R - Params[5];
+            if (e < 0) 
+                Val = 0;
+            else
+                Val = (pow(e, 1.0/Params[0]) - Params[2]) / Params[1];
+        }
+        else {
+            Val = (R - Params[6]) / Params[3];
+        }
+        break;
+
+
+    // Types 6,7,8 comes from segmented curves as described in ICCSpecRevision_02_11_06_Float.pdf
+    // Type 6 is basically identical to type 5 without d
+    
+    // Y = (a * X + b) ^ Gamma + c
+    case 6:    
+        e = Params[1]*R + Params[2];
+
+        if (e < 0) 
+            Val = 0;
+        else 
+            Val = pow(e, Params[0]) + Params[3];
+        break;
+
+    // ((Y - c) ^1/Gamma - b) / a                        
+    case -6:
+        e = R - Params[3];
+        if (e < 0)
+            Val = 0;
+        else 
+        Val = (pow(e, 1.0/Params[0]) - Params[2]) / Params[1];
+        break;
+
+
+    // Y = a * log (b * X^Gamma + c) + d
+    case 7:                   
+
+       e = Params[2] * pow(R, Params[0]) + Params[3];
+       if (e <= 0)
+           Val = 0;
+       else
+           Val = Params[1]*log10(e) + Params[4];
+       break;
+
+    // (Y - d) / a = log(b * X ^Gamma + c)
+    // pow(10, (Y-d) / a) = b * X ^Gamma + c
+    // pow((pow(10, (Y-d) / a) - c) / b, 1/g) = X 
+    case -7:
+       Val = pow((pow(10.0, (R-Params[4]) / Params[1]) - Params[3]) / Params[2], 1.0 / Params[0]);
+       break;
+
+
+   //Y = a * b^(c*X+d) + e          
+   case 8:
+       Val = (Params[0] * pow(Params[1], Params[2] * R + Params[3]) + Params[4]);
+       break;
+
+
+   // Y = (log((y-e) / a) / log(b) - d ) / c
+   // a=0, b=1, c=2, d=3, e=4,
+   case -8:
+             
+       disc = R - Params[4];
+       if (disc < 0) Val = 0;
+       else 
+           Val = (log(disc / Params[0]) / log(Params[1]) - Params[3]) / Params[2];         
+       break;
+
+   // S-Shaped: (1 - (1-x)^1/g)^1/g                    
+   case 108:
+      Val = pow(1.0 - pow(1 - R, 1/Params[0]), 1/Params[0]);
+      break;
+
+    // y = (1 - (1-x)^1/g)^1/g
+    // y^g = (1 - (1-x)^1/g)
+    // 1 - y^g = (1-x)^1/g
+    // (1 - y^g)^g = 1 - x
+    // 1 - (1 - y^g)^g
+    case -108:
+        Val = 1 - pow(1 - pow(R, Params[0]), Params[0]);
+        break;
+
+    default:
+        // Unsupported parametric curve. Should never reach here
+        return 0;
+    }
+
+    return Val;
+}
+
+// Evaluate a segmented funtion for a single value. Return -1 if no valid segment found .
+// If fn type is 0, perform an interpolation on the table 
+static
+cmsFloat64Number EvalSegmentedFn(const cmsToneCurve *g, cmsFloat64Number R)
+{
+    int i;
+
+    for (i = g ->nSegments-1; i >= 0 ; --i) {
+
+        // Check for domain
+        if ((R > g ->Segments[i].x0) && (R <= g ->Segments[i].x1)) {
+
+            // Type == 0 means segment is sampled
+            if (g ->Segments[i].Type == 0) {
+
+                cmsFloat32Number R1 = (cmsFloat32Number) (R - g ->Segments[i].x0);
+                cmsFloat32Number Out;
+
+                // Setup the table (TODO: clean that)
+                g ->SegInterp[i]-> Table = g ->Segments[i].SampledPoints; 
+
+                g ->SegInterp[i] -> Interpolation.LerpFloat(&R1, &Out, g ->SegInterp[i]);
+                
+                return Out;
+            }
+            else
+                return g ->Evals[i](g->Segments[i].Type, g ->Segments[i].Params, R);
+        }
+    }
+
+    return MINUS_INF;
+}
+
+
+// Create an empty gamma curve, by using tables. This specifies only the limited-precision part, and leaves the
+// floating point description empty.
+cmsToneCurve* CMSEXPORT cmsBuildTabulatedToneCurve16(cmsContext ContextID, cmsInt32Number nEntries, const cmsUInt16Number Values[])
+{
+    return AllocateToneCurveStruct(ContextID, nEntries, 0, NULL, Values);
+}
+
+static
+int EntriesByGamma(cmsFloat64Number Gamma)
+{
+    if (fabs(Gamma - 1.0) < 0.001) return 2;
+    return 4096;
+}
+
+
+// Create a segmented gamma, fill the table
+cmsToneCurve* CMSEXPORT cmsBuildSegmentedToneCurve(cmsContext ContextID, 
+                                                   cmsInt32Number nSegments, const cmsCurveSegment Segments[])
+{
+    int i;
+    cmsFloat64Number R, Val;
+    cmsToneCurve* g;
+    int nGridPoints = 4096;
+        
+    _cmsAssert(Segments != NULL);
+
+    // Optimizatin for identity curves. 
+    if (nSegments == 1 && Segments[0].Type == 1) {
+
+        nGridPoints = EntriesByGamma(Segments[0].Params[0]);
+    }
+
+    g = AllocateToneCurveStruct(ContextID, nGridPoints, nSegments, Segments, NULL);
+    if (g == NULL) return NULL;
+
+    // Once we have the floating point version, we can approximate a 16 bit table of 4096 entries
+    // for performance reasons. This table would normally not be used except on 8/16 bits transforms.
+    for (i=0; i < nGridPoints; i++) {
+
+        R   = (cmsFloat64Number) i / (nGridPoints-1);
+
+        Val = EvalSegmentedFn(g, R);
+
+        // Round and saturate
+        g ->Table16[i] = _cmsQuickSaturateWord(Val * 65535.0);
+    }
+
+    return g;
+}
+
+// Use a segmented curve to store the floating point table
+cmsToneCurve* CMSEXPORT cmsBuildTabulatedToneCurveFloat(cmsContext ContextID, cmsUInt32Number nEntries, const cmsFloat32Number values[])
+{
+    cmsCurveSegment Seg[2];
+
+    // Initialize segmented curve part up to 0
+    Seg[0].x0 = -1;
+    Seg[0].x1 = 0;
+    Seg[0].Type = 6;
+
+    Seg[0].Params[0] = 1;
+    Seg[0].Params[1] = 0;
+    Seg[0].Params[2] = 0;
+    Seg[0].Params[3] = 0;
+    Seg[0].Params[4] = 0;
+
+    // From zero to any
+    Seg[1].x0 = 0;
+    Seg[1].x1 = 1.0;   
+    Seg[1].Type = 0;
+
+    Seg[1].nGridPoints = nEntries;
+    Seg[1].SampledPoints = (cmsFloat32Number*) values;
+
+    return cmsBuildSegmentedToneCurve(ContextID, 2, Seg);
+}
+
+// Parametric curves
+//
+// Parameters goes as: Curve, a, b, c, d, e, f
+// Type is the ICC type +1
+// if type is negative, then the curve is analyticaly inverted
+cmsToneCurve* CMSEXPORT cmsBuildParametricToneCurve(cmsContext ContextID, cmsInt32Number Type, const cmsFloat64Number Params[])
+{
+    cmsCurveSegment Seg0;
+    int Pos = 0;
+    cmsUInt32Number size;
+    _cmsParametricCurvesCollection* c = GetParametricCurveByType(Type, &Pos);
+
+    _cmsAssert(Params != NULL);
+
+    if (c == NULL) {
+         cmsSignalError(ContextID, cmsERROR_UNKNOWN_EXTENSION, "Invalid parametric curve type %d", Type);     
+        return NULL;
+    }
+
+    memset(&Seg0, 0, sizeof(Seg0));
+
+    Seg0.x0   = MINUS_INF;
+    Seg0.x1   = PLUS_INF;
+    Seg0.Type = Type;
+
+    size = c->ParameterCount[Pos] * sizeof(cmsFloat64Number);
+    memmove(Seg0.Params, Params, size);
+
+    return cmsBuildSegmentedToneCurve(ContextID, 1, &Seg0);
+}
+
+
+
+// Build a gamma table based on gamma constant
+cmsToneCurve* CMSEXPORT cmsBuildGamma(cmsContext ContextID, cmsFloat64Number Gamma)
+{
+    return cmsBuildParametricToneCurve(ContextID, 1, &Gamma);
+}
+
+
+// Free all memory taken by the gamma curve
+void CMSEXPORT cmsFreeToneCurve(cmsToneCurve* Curve)
+{
+    cmsContext ContextID;
+    
+    if (Curve == NULL) return;
+
+    ContextID = Curve ->InterpParams->ContextID;
+
+    _cmsFreeInterpParams(Curve ->InterpParams);
+    
+    if (Curve -> Table16)
+        _cmsFree(ContextID, Curve ->Table16);
+
+    if (Curve ->Segments) {
+
+        cmsUInt32Number i;
+        
+        for (i=0; i < Curve ->nSegments; i++) {
+
+            if (Curve ->Segments[i].SampledPoints) {
+                _cmsFree(ContextID, Curve ->Segments[i].SampledPoints);
+            }
+
+            if (Curve ->SegInterp[i] != 0) 
+                _cmsFreeInterpParams(Curve->SegInterp[i]);
+        }
+
+        _cmsFree(ContextID, Curve ->Segments);
+        _cmsFree(ContextID, Curve ->SegInterp);
+    }
+
+    if (Curve -> Evals)
+        _cmsFree(ContextID, Curve -> Evals);
+
+    if (Curve) _cmsFree(ContextID, Curve);
+}
+
+// Utility function, free 3 gamma tables
+void CMSEXPORT cmsFreeToneCurveTriple(cmsToneCurve* Curve[3])
+{
+
+    _cmsAssert(Curve != NULL);
+
+    if (Curve[0] != NULL) cmsFreeToneCurve(Curve[0]);
+    if (Curve[1] != NULL) cmsFreeToneCurve(Curve[1]);
+    if (Curve[2] != NULL) cmsFreeToneCurve(Curve[2]);
+
+    Curve[0] = Curve[1] = Curve[2] = NULL;
+}
+
+
+// Duplicate a gamma table
+cmsToneCurve* CMSEXPORT cmsDupToneCurve(const cmsToneCurve* In)
+{   
+    if (In == NULL) return NULL;
+
+    return  AllocateToneCurveStruct(In ->InterpParams ->ContextID, In ->nEntries, In ->nSegments, In ->Segments, In ->Table16);
+}
+
+// Joins two curves for X and Y. Curves should be monotonic.
+// We want to get 
+//
+//      y = Y^-1(X(t)) 
+//
+cmsToneCurve* CMSEXPORT cmsJoinToneCurve(cmsContext ContextID, 
+                                      const cmsToneCurve* X,
+                                      const cmsToneCurve* Y, cmsUInt32Number nResultingPoints)
+{
+    cmsToneCurve* out = NULL;
+    cmsToneCurve* Yreversed = NULL;
+    cmsFloat32Number t, x;
+    cmsFloat32Number* Res = NULL;
+    cmsUInt32Number i;
+
+
+    _cmsAssert(X != NULL);
+    _cmsAssert(Y != NULL);
+
+    Yreversed = cmsReverseToneCurveEx(nResultingPoints, Y);
+    if (Yreversed == NULL) goto Error;
+
+    Res = (cmsFloat32Number*) _cmsCalloc(ContextID, nResultingPoints, sizeof(cmsFloat32Number));
+    if (Res == NULL) goto Error;
+    
+    //Iterate
+    for (i=0; i <  nResultingPoints; i++) {
+
+        t = (cmsFloat32Number) i / (nResultingPoints-1);
+        x = cmsEvalToneCurveFloat(X,  t);
+        Res[i] = cmsEvalToneCurveFloat(Yreversed, x);
+    }
+
+    // Allocate space for output
+    out = cmsBuildTabulatedToneCurveFloat(ContextID, nResultingPoints, Res);
+    
+Error:
+
+    if (Res != NULL) _cmsFree(ContextID, Res);
+    if (Yreversed != NULL) cmsFreeToneCurve(Yreversed);
+
+    return out;
+}
+
+
+
+// Get the surrounding nodes. This is tricky on non-monotonic tables 
+static
+int GetInterval(cmsFloat64Number In, const cmsUInt16Number LutTable[], const struct _cms_interp_struc* p)
+{   
+    int i;
+    int y0, y1;
+    
+    // A 1 point table is not allowed
+    if (p -> Domain[0] < 1) return -1;
+
+    // Let's see if ascending or descending. 
+    if (LutTable[0] < LutTable[p ->Domain[0]]) {
+
+        // Table is overall ascending
+        for (i=p->Domain[0]-1; i >=0; --i) {
+
+            y0 = LutTable[i]; 
+            y1 = LutTable[i+1];
+            
+            if (y0 <= y1) { // Increasing
+                if (In >= y0 && In <= y1) return i;
+            }
+            else
+                if (y1 < y0) { // Decreasing
+                    if (In >= y1 && In <= y0) return i;
+                }
+        }
+    }
+    else {
+        // Table is overall descending
+        for (i=0; i < (int) p -> Domain[0]; i++) {
+
+            y0 = LutTable[i]; 
+            y1 = LutTable[i+1];
+
+            if (y0 <= y1) { // Increasing
+                if (In >= y0 && In <= y1) return i;
+            }
+            else
+                if (y1 < y0) { // Decreasing
+                    if (In >= y1 && In <= y0) return i;
+                }
+        }
+    }
+
+    return -1;
+}
+
+// Reverse a gamma table
+cmsToneCurve* CMSEXPORT cmsReverseToneCurveEx(cmsInt32Number nResultSamples, const cmsToneCurve* InCurve)
+{
+    cmsToneCurve *out;
+    cmsFloat64Number a = 1, b = 0, y, x1, y1, x2, y2;
+    int i, j;
+    int Ascending;
+    
+    _cmsAssert(InCurve != NULL);
+
+    // Try to reverse it analytically whatever possible
+    if (InCurve ->nSegments == 1 && InCurve ->Segments[0].Type > 0 && InCurve -> Segments[0].Type <= 5) {
+
+        return cmsBuildParametricToneCurve(InCurve ->InterpParams->ContextID, 
+                                       -(InCurve -> Segments[0].Type), 
+                                       InCurve -> Segments[0].Params);
+    }
+
+    // Nope, reverse the table. 
+    out = cmsBuildTabulatedToneCurve16(InCurve ->InterpParams->ContextID, nResultSamples, NULL);
+    if (out == NULL)
+        return NULL;
+
+    // We want to know if this is an ascending or descending table
+    Ascending = !cmsIsToneCurveDescending(InCurve);
+
+    // Iterate across Y axis
+    for (i=0; i <  nResultSamples; i++) {
+
+        y = (cmsFloat64Number) i * 65535.0 / (nResultSamples - 1);
+
+        // Find interval in which y is within. 
+        j = GetInterval(y, InCurve->Table16, InCurve->InterpParams);
+        if (j >= 0) {
+
+            // Get limits of interval
+            x1 = InCurve ->Table16[j]; 
+            x2 = InCurve ->Table16[j+1];
+
+            y1 = (cmsFloat64Number) (j * 65535.0) / (InCurve ->nEntries - 1);
+            y2 = (cmsFloat64Number) ((j+1) * 65535.0 ) / (InCurve ->nEntries - 1);
+    
+            // If collapsed, then use any
+            if (x1 == x2) {
+
+                out ->Table16[i] = _cmsQuickSaturateWord(Ascending ? y2 : y1);
+                continue;
+
+            } else {
+
+                // Interpolate      
+                a = (y2 - y1) / (x2 - x1);
+                b = y2 - a * x2;
+            }
+        }
+           
+        out ->Table16[i] = _cmsQuickSaturateWord(a* y + b);
+    }
+
+    return out;
+}
+
+// Reverse a gamma table
+cmsToneCurve* CMSEXPORT cmsReverseToneCurve(const cmsToneCurve* InGamma)
+{
+    _cmsAssert(InGamma != NULL);
+
+    return cmsReverseToneCurveEx(InGamma -> nEntries, InGamma);
+}
+
+// From: Eilers, P.H.C. (1994) Smoothing and interpolation with finite
+// differences. in: Graphic Gems IV, Heckbert, P.S. (ed.), Academic press.
+//
+// Smoothing and interpolation with second differences.
+//
+//   Input:  weights (w), data (y): vector from 1 to m.
+//   Input:  smoothing parameter (lambda), length (m).
+//   Output: smoothed vector (z): vector from 1 to m.
+
+static
+cmsBool smooth2(cmsContext ContextID, cmsFloat32Number w[], cmsFloat32Number y[], cmsFloat32Number z[], cmsFloat32Number lambda, int m)
+{
+    int i, i1, i2;
+    cmsFloat32Number *c, *d, *e;
+    cmsBool st;
+
+
+    c = (cmsFloat32Number*) _cmsCalloc(ContextID, MAX_NODES_IN_CURVE, sizeof(cmsFloat32Number));
+    d = (cmsFloat32Number*) _cmsCalloc(ContextID, MAX_NODES_IN_CURVE, sizeof(cmsFloat32Number));
+    e = (cmsFloat32Number*) _cmsCalloc(ContextID, MAX_NODES_IN_CURVE, sizeof(cmsFloat32Number));
+    
+    if (c != NULL && d != NULL && e != NULL) {
+
+
+    d[1] = w[1] + lambda;
+    c[1] = -2 * lambda / d[1];
+    e[1] = lambda /d[1];
+    z[1] = w[1] * y[1];
+    d[2] = w[2] + 5 * lambda - d[1] * c[1] *  c[1];
+    c[2] = (-4 * lambda - d[1] * c[1] * e[1]) / d[2];
+    e[2] = lambda / d[2];
+    z[2] = w[2] * y[2] - c[1] * z[1];
+    
+    for (i = 3; i < m - 1; i++) {
+        i1 = i - 1; i2 = i - 2;
+        d[i]= w[i] + 6 * lambda - c[i1] * c[i1] * d[i1] - e[i2] * e[i2] * d[i2];
+        c[i] = (-4 * lambda -d[i1] * c[i1] * e[i1])/ d[i];
+        e[i] = lambda / d[i];
+        z[i] = w[i] * y[i] - c[i1] * z[i1] - e[i2] * z[i2];
+    }
+    
+    i1 = m - 2; i2 = m - 3;
+    
+    d[m - 1] = w[m - 1] + 5 * lambda -c[i1] * c[i1] * d[i1] - e[i2] * e[i2] * d[i2];
+    c[m - 1] = (-2 * lambda - d[i1] * c[i1] * e[i1]) / d[m - 1];
+    z[m - 1] = w[m - 1] * y[m - 1] - c[i1] * z[i1] - e[i2] * z[i2];
+    i1 = m - 1; i2 = m - 2;
+    
+    d[m] = w[m] + lambda - c[i1] * c[i1] * d[i1] - e[i2] * e[i2] * d[i2];
+    z[m] = (w[m] * y[m] - c[i1] * z[i1] - e[i2] * z[i2]) / d[m];
+    z[m - 1] = z[m - 1] / d[m - 1] - c[m - 1] * z[m];
+    
+    for (i = m - 2; 1<= i; i--)
+        z[i] = z[i] / d[i] - c[i] * z[i + 1] - e[i] * z[i + 2];
+
+      st = TRUE;
+    }
+    else st = FALSE;
+
+    if (c != NULL) _cmsFree(ContextID, c);
+    if (d != NULL) _cmsFree(ContextID, d);
+    if (e != NULL) _cmsFree(ContextID, e);
+
+    return st;
+}
+
+// Smooths a curve sampled at regular intervals. 
+cmsBool  CMSEXPORT cmsSmoothToneCurve(cmsToneCurve* Tab, cmsFloat64Number lambda)
+{
+    cmsFloat32Number w[MAX_NODES_IN_CURVE], y[MAX_NODES_IN_CURVE], z[MAX_NODES_IN_CURVE];
+    int i, nItems, Zeros, Poles;
+
+    if (Tab == NULL) return FALSE;
+
+    if (cmsIsToneCurveLinear(Tab)) return FALSE; // Nothing to do
+
+    nItems = Tab -> nEntries;
+
+    if (nItems >= MAX_NODES_IN_CURVE) {
+        cmsSignalError(Tab ->InterpParams->ContextID, cmsERROR_RANGE, "cmsSmoothToneCurve: too many points.");
+        return FALSE;
+    }
+
+    memset(w, 0, nItems * sizeof(cmsFloat32Number));
+    memset(y, 0, nItems * sizeof(cmsFloat32Number));
+    memset(z, 0, nItems * sizeof(cmsFloat32Number));
+
+    for (i=0; i < nItems; i++)
+    {
+        y[i+1] = (cmsFloat32Number) Tab -> Table16[i];
+        w[i+1] = 1.0;
+    }
+
+    if (!smooth2(Tab ->InterpParams->ContextID, w, y, z, (cmsFloat32Number) lambda, nItems)) return FALSE;
+
+    // Do some reality - checking...
+    Zeros = Poles = 0;
+    for (i=nItems; i > 1; --i) {
+
+        if (z[i] == 0.) Zeros++;
+        if (z[i] >= 65535.) Poles++;
+        if (z[i] < z[i-1]) return FALSE; // Non-Monotonic
+    }
+
+    if (Zeros > (nItems / 3)) return FALSE;  // Degenerated, mostly zeros
+    if (Poles > (nItems / 3)) return FALSE;  // Degenerated, mostly poles
+
+    // Seems ok
+    for (i=0; i < nItems; i++) {
+
+        // Clamp to cmsUInt16Number
+        Tab -> Table16[i] = _cmsQuickSaturateWord(z[i+1]);
+    }
+
+    return TRUE;
+}
+
+// Is a table linear? Do not use parametric since we cannot guarantee some weird parameters resulting
+// in a linear table. This way assures it is linear in 12 bits, which should be enought in most cases.
+cmsBool CMSEXPORT cmsIsToneCurveLinear(const cmsToneCurve* Curve)
+{
+    cmsUInt32Number i;
+    int diff;
+
+    _cmsAssert(Curve != NULL);
+
+    for (i=0; i < Curve ->nEntries; i++) {
+
+        diff = abs((int) Curve->Table16[i] - (int) _cmsQuantizeVal(i, Curve ->nEntries));
+        if (diff > 0x0f)
+            return FALSE;
+    }
+
+    return TRUE;
+}
+
+// Same, but for monotonicity
+cmsBool  CMSEXPORT cmsIsToneCurveMonotonic(const cmsToneCurve* t)
+{
+    int n;
+    int i, last;
+
+    _cmsAssert(t != NULL);
+
+    n    = t ->nEntries;
+    last = t ->Table16[n-1];
+
+    for (i = n-2; i >= 0; --i) {
+
+        if (t ->Table16[i] > last)
+
+            return FALSE;
+        else
+            last = t ->Table16[i];
+
+    }
+
+    return TRUE;
+}
+
+// Same, but for descending tables
+cmsBool  CMSEXPORT cmsIsToneCurveDescending(const cmsToneCurve* t)
+{
+    _cmsAssert(t != NULL);
+
+    return t ->Table16[0] > t ->Table16[t ->nEntries-1];
+}
+
+
+// Another info fn: is out gamma table multisegment?
+cmsBool  CMSEXPORT cmsIsToneCurveMultisegment(const cmsToneCurve* t)
+{
+    _cmsAssert(t != NULL);
+
+    return t -> nSegments > 1;
+}
+
+cmsInt32Number  CMSEXPORT cmsGetToneCurveParametricType(const cmsToneCurve* t)
+{
+    _cmsAssert(t != NULL);
+
+    if (t -> nSegments != 1) return 0;
+    return t ->Segments[0].Type;
+}
+
+// We need accuracy this time
+cmsFloat32Number CMSEXPORT cmsEvalToneCurveFloat(const cmsToneCurve* Curve, cmsFloat32Number v)
+{
+    _cmsAssert(Curve != NULL);
+
+    // Check for 16 bits table. If so, this is a limited-precision tone curve
+    if (Curve ->nSegments == 0) {
+
+        cmsUInt16Number In, Out;
+        
+        In = (cmsUInt16Number) _cmsQuickSaturateWord(v * 65535.0);
+        Out = cmsEvalToneCurve16(Curve, In);
+        
+        return (cmsFloat32Number) (Out / 65535.0);
+    }
+
+    return (cmsFloat32Number) EvalSegmentedFn(Curve, v);
+}
+
+// We need xput over here
+cmsUInt16Number CMSEXPORT cmsEvalToneCurve16(const cmsToneCurve* Curve, cmsUInt16Number v)
+{
+    cmsUInt16Number out;
+
+    _cmsAssert(Curve != NULL);
+
+    Curve ->InterpParams ->Interpolation.Lerp16(&v, &out, Curve ->InterpParams);
+    return out;
+}
+
+
+// Least squares fitting.
+// A mathematical procedure for finding the best-fitting curve to a given set of points by 
+// minimizing the sum of the squares of the offsets ("the residuals") of the points from the curve. 
+// The sum of the squares of the offsets is used instead of the offset absolute values because 
+// this allows the residuals to be treated as a continuous differentiable quantity. 
+//
+// y = f(x) = x ^ g
+//
+// R  = (yi - (xi^g))
+// R2 = (yi - (xi^g))2
+// SUM R2 = SUM (yi - (xi^g))2
+// 
+// dR2/dg = -2 SUM x^g log(x)(y - x^g)    
+// solving for dR2/dg = 0 
+// 
+// g = 1/n * SUM(log(y) / log(x)) 
+
+cmsFloat64Number CMSEXPORT cmsEstimateGamma(const cmsToneCurve* t, cmsFloat64Number Precision)
+{
+    cmsFloat64Number gamma, sum, sum2;
+    cmsFloat64Number n, x, y, Std;
+    cmsUInt32Number i;
+
+    _cmsAssert(t != NULL);
+
+    sum = sum2 = n = 0;
+
+    // Excluding endpoints   
+    for (i=1; i < (MAX_NODES_IN_CURVE-1); i++) {
+
+        x = (cmsFloat64Number) i / (MAX_NODES_IN_CURVE-1);
+        y = (cmsFloat64Number) cmsEvalToneCurveFloat(t, (cmsFloat32Number) x);
+
+        // Avoid 7% on lower part to prevent 
+        // artifacts due to linear ramps
+
+        if (y > 0. && y < 1. && x > 0.07) {
+
+            gamma = log(y) / log(x);
+            sum  += gamma;
+            sum2 += gamma * gamma;
+            n++;
+        }
+    }
+
+    // Take a look on SD to see if gamma isn't exponential at all
+    Std = sqrt((n * sum2 - sum * sum) / (n*(n-1)));
+
+    if (Std > Precision)
+        return -1.0;
+
+    return (sum / n);   // The mean
+}