chromium/third_party/pdfium/third_party/lcms/src/cmswtpnt.c

//---------------------------------------------------------------------------------
//
//  Little Color Management System
//  Copyright (c) 1998-2023 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"


// D50 - Widely used
const cmsCIEXYZ* CMSEXPORT cmsD50_XYZ(void)
{ … }

const cmsCIExyY* CMSEXPORT cmsD50_xyY(void)
{ … }

// Obtains WhitePoint from Temperature
cmsBool  CMSEXPORT cmsWhitePointFromTemp(cmsCIExyY* WhitePoint, cmsFloat64Number TempK)
{ … }



ISOTEMPERATURE;

static const ISOTEMPERATURE isotempdata[] = …;

#define NISO …


// Robertson's method
cmsBool  CMSEXPORT cmsTempFromWhitePoint(cmsFloat64Number* TempK, const cmsCIExyY* WhitePoint)
{ … }


// Compute chromatic adaptation matrix using Chad as cone matrix

static
cmsBool ComputeChromaticAdaptation(cmsMAT3* Conversion,
                                const cmsCIEXYZ* SourceWhitePoint,
                                const cmsCIEXYZ* DestWhitePoint,
                                const cmsMAT3* Chad)

{ … }

// Returns the final chrmatic adaptation from illuminant FromIll to Illuminant ToIll
// The cone matrix can be specified in ConeMatrix. If NULL, Bradford is assumed
cmsBool  _cmsAdaptationMatrix(cmsMAT3* r, const cmsMAT3* ConeMatrix, const cmsCIEXYZ* FromIll, const cmsCIEXYZ* ToIll)
{ … }

// Same as anterior, but assuming D50 destination. White point is given in xyY
static
cmsBool _cmsAdaptMatrixToD50(cmsMAT3* r, const cmsCIExyY* SourceWhitePt)
{ … }

// 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 assuming that the gamma correction
// has transitive property in the transformation chain.
//
// the algorithm:
//
//            - 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 coefficients of the transformation
//            - Then, I apply these coefficients to the original matrix
//
cmsBool _cmsBuildRGB2XYZtransferMatrix(cmsMAT3* r, const cmsCIExyY* WhitePt, const cmsCIExyYTRIPLE* Primrs)
{ … }


// Adapts a color to a given illuminant. Original color is expected to have
// a SourceWhitePt white point.
cmsBool CMSEXPORT cmsAdaptToIlluminant(cmsCIEXYZ* Result,
                                       const cmsCIEXYZ* SourceWhitePt,
                                       const cmsCIEXYZ* Illuminant,
                                       const cmsCIEXYZ* Value)
{ … }