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223 lines
7.5 KiB
C
223 lines
7.5 KiB
C
/* $Xorg: LuvGcLC.c,v 1.3 2000/08/17 19:44:41 cpqbld Exp $ */
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/*
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* Code and supporting documentation (c) Copyright 1990 1991 Tektronix, Inc.
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* All Rights Reserved
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*
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* This file is a component of an X Window System-specific implementation
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* of XCMS based on the TekColor Color Management System. Permission is
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* hereby granted to use, copy, modify, sell, and otherwise distribute this
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* software and its documentation for any purpose and without fee, provided
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* that this copyright, permission, and disclaimer notice is reproduced in
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* all copies of this software and in supporting documentation. TekColor
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* is a trademark of Tektronix, Inc.
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*
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* Tektronix makes no representation about the suitability of this software
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* for any purpose. It is provided "as is" and with all faults.
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*
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* TEKTRONIX DISCLAIMS ALL WARRANTIES APPLICABLE TO THIS SOFTWARE,
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* INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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* PARTICULAR PURPOSE. IN NO EVENT SHALL TEKTRONIX BE LIABLE FOR ANY
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* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
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* RESULTING FROM LOSS OF USE, DATA, OR PROFITS, WHETHER IN AN ACTION OF
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* CONTRACT, NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
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* CONNECTION WITH THE USE OR THE PERFORMANCE OF THIS SOFTWARE.
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*
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* NAME
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* CIELuvGcLC.c
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*
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* DESCRIPTION
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* Source for XcmsCIELuvClipLuv() gamut
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* compression function.
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*/
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/* $XFree86: xc/lib/X11/LuvGcLC.c,v 1.4 2003/04/13 19:22:17 dawes Exp $ */
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#include "Xlibint.h"
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#include "Xcmsint.h"
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#include <math.h>
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#include "Cv.h"
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/*
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* INTERNALS
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* Internal defines that need NOT be exported to any package or
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* program using this package.
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*/
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#define MAXBISECTCOUNT 100
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/************************************************************************
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* *
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* PUBLIC ROUTINES *
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* *
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************************************************************************/
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/*
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* NAME
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* XcmsCIELuvClipLuv - Return the closest L* and chroma
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*
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* SYNOPSIS
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*/
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/* ARGSUSED */
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Status
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XcmsCIELuvClipLuv (ccc, pColors_in_out, nColors, i, pCompressed)
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XcmsCCC ccc;
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XcmsColor *pColors_in_out;
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unsigned int nColors;
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unsigned int i;
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Bool *pCompressed;
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/*
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* DESCRIPTION
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* This routine will find the closest L* and chroma
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* for a specific hue. The color input is converted to
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* CIE L*u*v* format and returned as CIE XYZ format.
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*
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* Since this routine works with the L* within
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* pColor_in_out intermediate results may be returned
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* even though it may be invalid.
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*
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* RETURNS
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* XcmsFailure - Failure
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* XcmsSuccess - Succeeded
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*
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*/
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{
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Status retval;
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XcmsCCCRec myCCC;
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XcmsColor *pColor;
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XcmsColor Luv_max;
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XcmsFloat hue, chroma, maxChroma;
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XcmsFloat Chroma, bestChroma, Lstar, maxLstar, saveLstar;
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XcmsFloat bestLstar, bestustar, bestvstar;
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XcmsFloat nT, saveDist, tmpDist;
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XcmsRGBi rgb_max;
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int nCount, nMaxCount, nI, nILast;
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/* Use my own CCC */
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memcpy ((char *)&myCCC, (char *)ccc, sizeof(XcmsCCCRec));
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myCCC.clientWhitePt.format = XcmsUndefinedFormat;/* inherit screen white */
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myCCC.gamutCompProc = (XcmsCompressionProc)NULL;/* no gamut compression func */
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/*
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* Color specification passed as input can be assumed to:
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* 1. Be in XcmsCIEXYZFormat
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* 2. Already be white point adjusted for the Screen White Point.
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* This means that the white point now associated with this
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* color spec is the Screen White Point (even if the
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* ccc->clientWhitePt differs).
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*/
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pColor = pColors_in_out + i;
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if (ccc->visual->class < StaticColor) {
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/*
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* GRAY !
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*/
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_XcmsDIConvertColors(ccc, pColor, ScreenWhitePointOfCCC(ccc),
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1, XcmsCIELuvFormat);
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_XcmsDIConvertColors(ccc, pColor, ScreenWhitePointOfCCC(ccc),
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1, XcmsCIEXYZFormat);
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if (pCompressed) {
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*(pCompressed + i) = True;
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}
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return(XcmsSuccess);
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}
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/* Convert from CIEXYZ to CIELuv format */
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if (_XcmsDIConvertColors(&myCCC, pColor,
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ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIELuvFormat)
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== XcmsFailure) {
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return(XcmsFailure);
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}
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/* Step 1: compute the maximum L* and chroma for this hue. */
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/* This copy may be overkill but it preserves the pixel etc. */
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saveLstar = pColor->spec.CIELuv.L_star;
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hue = XCMS_CIELUV_PMETRIC_HUE(pColor->spec.CIELuv.u_star,
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pColor->spec.CIELuv.v_star);
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chroma = XCMS_CIELUV_PMETRIC_CHROMA(pColor->spec.CIELuv.u_star,
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pColor->spec.CIELuv.v_star);
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memcpy((char *)&Luv_max, (char *)pColor, sizeof(XcmsColor));
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if (_XcmsCIELuvQueryMaxLCRGB (&myCCC, hue, &Luv_max, &rgb_max)
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== XcmsFailure) {
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return (XcmsFailure);
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}
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maxLstar = Luv_max.spec.CIELuv.L_star;
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/* Now check and return the appropriate L* */
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if (saveLstar == maxLstar) {
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/* When the L* input is equal to the maximum L* */
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/* merely return the maximum Luv point. */
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memcpy((char *)pColor, (char *)&Luv_max, sizeof(XcmsColor));
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retval = _XcmsDIConvertColors(&myCCC, pColor,
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ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIEXYZFormat);
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} else {
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/* return the closest point on the hue leaf. */
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/* must do a bisection here to compute the delta e. */
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maxChroma = XCMS_CIELUV_PMETRIC_CHROMA(Luv_max.spec.CIELuv.u_star,
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Luv_max.spec.CIELuv.v_star);
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nMaxCount = MAXBISECTCOUNT;
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nI = nMaxCount / 2;
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bestLstar = Lstar = pColor->spec.CIELuv.L_star;
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bestustar = pColor->spec.CIELuv.u_star;
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bestvstar = pColor->spec.CIELuv.v_star;
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bestChroma = Chroma = chroma;
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saveDist = XCMS_SQRT(((Chroma - maxChroma) * (Chroma - maxChroma)) +
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((Lstar - maxLstar) * (Lstar - maxLstar)));
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for (nCount = 0; nCount < nMaxCount; nCount++) {
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nT = (XcmsFloat) nI / (XcmsFloat) nMaxCount;
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if (saveLstar > maxLstar) {
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pColor->spec.RGBi.red = rgb_max.red * (1.0 - nT) + nT;
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pColor->spec.RGBi.green = rgb_max.green * (1.0 - nT) + nT;
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pColor->spec.RGBi.blue = rgb_max.blue * (1.0 - nT) + nT;
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} else {
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pColor->spec.RGBi.red = rgb_max.red - (rgb_max.red * nT);
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pColor->spec.RGBi.green = rgb_max.green - (rgb_max.green * nT);
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pColor->spec.RGBi.blue = rgb_max.blue - (rgb_max.blue * nT);
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}
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pColor->format = XcmsRGBiFormat;
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/* Convert from RGBi to CIE Luv */
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if (_XcmsConvertColorsWithWhitePt(&myCCC, pColor,
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ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIELuvFormat,
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(Bool *) NULL) == XcmsFailure) {
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return (XcmsFailure);
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}
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chroma = XCMS_CIELUV_PMETRIC_CHROMA(pColor->spec.CIELuv.u_star,
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pColor->spec.CIELuv.v_star);
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tmpDist = XCMS_SQRT(((Chroma - chroma) * (Chroma - chroma)) +
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((Lstar - pColor->spec.CIELuv.L_star) *
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(Lstar - pColor->spec.CIELuv.L_star)));
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nILast = nI;
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if (tmpDist > saveDist) {
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nI /= 2;
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} else {
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nI = (nMaxCount + nI) / 2;
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saveDist = tmpDist;
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bestLstar = pColor->spec.CIELuv.L_star;
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bestustar = pColor->spec.CIELuv.u_star;
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bestvstar = pColor->spec.CIELuv.v_star;
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bestChroma = chroma;
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}
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if (nI == nILast || nI == 0) {
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break;
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}
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}
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if (bestChroma >= maxChroma) {
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pColor->spec.CIELuv.L_star = maxLstar;
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pColor->spec.CIELuv.u_star = Luv_max.spec.CIELuv.u_star;
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pColor->spec.CIELuv.v_star = Luv_max.spec.CIELuv.v_star;
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} else {
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pColor->spec.CIELuv.L_star = bestLstar;
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pColor->spec.CIELuv.u_star = bestustar;
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pColor->spec.CIELuv.v_star = bestvstar;
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}
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retval = _XcmsDIConvertColors(&myCCC, pColor,
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ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIEXYZFormat);
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if (retval != XcmsFailure && pCompressed != NULL) {
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*(pCompressed + i) = True;
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}
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}
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return(retval);
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}
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