src/common/tonemap.c

#ifndef lint
static const char       RCSid[] = "$Id: tonemap.c,v 3.34 2009/02/09 20:48:08 greg Exp $";
#endif
/*
 * Tone mapping functions.
 * See tonemap.h for detailed function descriptions.
 * Added von Kries white-balance calculations 10/01 (GW).
 *
 * Externals declared in tonemap.h
 */

#include "copyright.h"

#include        <stdio.h>
#include        <stdlib.h>
#include        <math.h>
#include        "tmprivat.h"
#include        "tmerrmsg.h"

#define exp10(x)        exp(M_LN10*(x))

                                        /* our list of conversion packages */
struct tmPackage        *tmPkg[TM_MAXPKG];
int     tmNumPkgs = 0;                  /* number of registered packages */

                                        /* luminance->brightness lookup */
static TMbright         *tmFloat2BrtLUT = NULL;

#define tmCvLumLUfp(pf) tmFloat2BrtLUT[*(int32 *)(pf) >> 15]


TMstruct *
tmInit(                                 /* initialize new tone mapping */
int     flags,
RGBPRIMP        monpri,
double  gamval
)
{
        COLORMAT        cmat;
        TMstruct        *tmnew;
        int     i;
                                                /* allocate structure */
        tmnew = (TMstruct *)malloc(sizeof(TMstruct));
        if (tmnew == NULL)
                return(NULL);

        tmnew->flags = flags & ~TM_F_UNIMPL;
        if (tmnew->flags & TM_F_BW)
                tmnew->flags &= ~TM_F_MESOPIC;
                                                /* set monitor transform */
        if (monpri == NULL || monpri == stdprims || tmnew->flags & TM_F_BW) {
                tmnew->monpri = stdprims;
                tmnew->clf[RED] = rgb2xyzmat[1][0];
                tmnew->clf[GRN] = rgb2xyzmat[1][1];
                tmnew->clf[BLU] = rgb2xyzmat[1][2];
        } else {
                comprgb2xyzmat(cmat, tmnew->monpri=monpri);
                tmnew->clf[RED] = cmat[1][0];
                tmnew->clf[GRN] = cmat[1][1];
                tmnew->clf[BLU] = cmat[1][2];
        }
                                                /* set gamma value */
        if (gamval < MINGAM)
                tmnew->mongam = DEFGAM;
        else
                tmnew->mongam = gamval;
                                                /* set color divisors */
        for (i = 0; i < 3; i++)
                tmnew->cdiv[i] = 256.*pow(tmnew->clf[i], 1./tmnew->mongam);

                                                /* set input transform */
        tmnew->inppri = tmnew->monpri;
        tmnew->cmat[0][0] = tmnew->cmat[1][1] = tmnew->cmat[2][2] =
                        tmnew->inpsf = WHTEFFICACY;
        tmnew->cmat[0][1] = tmnew->cmat[0][2] = tmnew->cmat[1][0] =
        tmnew->cmat[1][2] = tmnew->cmat[2][0] = tmnew->cmat[2][1] = 0.;
        tmnew->inpdat = NULL;
        tmnew->hbrmin = 10; tmnew->hbrmax = -10;
        tmnew->histo = NULL;
        tmnew->mbrmin = 10; tmnew->mbrmax = -10;
        tmnew->lumap = NULL;
                                                /* zero private data */
        for (i = TM_MAXPKG; i--; )
                tmnew->pd[i] = NULL;
        tmnew->lastError = TM_E_OK;
        tmnew->lastFunc = "NoErr";
                                                /* return new TMstruct */
        return(tmnew);
}


int
tmSetSpace(                     /* set input color space for conversions */
TMstruct        *tms,
RGBPRIMP        pri,
double  sf,
MEM_PTR dat
)
{
        static const char funcName[] = "tmSetSpace";
        int     i, j;
                                                /* error check */
        if (tms == NULL)
                returnErr(TM_E_TMINVAL);
        if (sf <= 1e-12)
                returnErr(TM_E_ILLEGAL);
                                                /* check if no change */
        if (pri == tms->inppri && FEQ(sf, tms->inpsf) && dat == tms->inpdat)
                returnOK;
        tms->inppri = pri;                      /* let's set it */
        tms->inpsf = sf;
        tms->inpdat = dat;

        if (tms->flags & TM_F_BW) {             /* color doesn't matter */
                tms->monpri = tms->inppri;              /* eliminate xform */
                if (tms->inppri == TM_XYZPRIM) {
                        tms->clf[CIEX] = tms->clf[CIEZ] = 0.;
                        tms->clf[CIEY] = 1.;
                } else {
                        comprgb2xyzmat(tms->cmat, tms->monpri);
                        tms->clf[RED] = tms->cmat[1][0];
                        tms->clf[GRN] = tms->cmat[1][1];
                        tms->clf[BLU] = tms->cmat[1][2];
                }
                tms->cmat[0][0] = tms->cmat[1][1] = tms->cmat[2][2] =
                                tms->inpsf;
                tms->cmat[0][1] = tms->cmat[0][2] = tms->cmat[1][0] =
                tms->cmat[1][2] = tms->cmat[2][0] = tms->cmat[2][1] = 0.;

        } else if (tms->inppri == TM_XYZPRIM)   /* input is XYZ */
                compxyz2rgbWBmat(tms->cmat, tms->monpri);

        else {                                  /* input is RGB */
                if (tms->inppri != tms->monpri &&
                                PRIMEQ(tms->inppri, tms->monpri))
                        tms->inppri = tms->monpri;      /* no xform */
                comprgb2rgbWBmat(tms->cmat, tms->inppri, tms->monpri);
        }
        for (i = 0; i < 3; i++)
                for (j = 0; j < 3; j++)
                        tms->cmat[i][j] *= tms->inpsf;
                                                /* set color divisors */
        for (i = 0; i < 3; i++)
                if (tms->clf[i] > .001)
                        tms->cdiv[i] =
                                256.*pow(tms->clf[i], 1./tms->mongam);
                else
                        tms->cdiv[i] = 1;
                                                /* notify packages */
        for (i = tmNumPkgs; i--; )
                if (tms->pd[i] != NULL && tmPkg[i]->NewSpace != NULL)
                        (*tmPkg[i]->NewSpace)(tms);
        returnOK;
}


void
tmClearHisto(                           /* clear current histogram */
TMstruct        *tms
)
{
        if (tms == NULL || tms->histo == NULL)
                return;
        free((MEM_PTR)tms->histo);
        tms->histo = NULL;
}


TMbright
tmCvLuminance(                          /* convert a single luminance */
double  lum
)
{
        double  d;

#ifdef isfinite
        if (!isfinite(lum) || lum <= TM_NOLUM)
#else
        if (lum <= TM_NOLUM)
#endif
                return(TM_NOBRT);
        d = TM_BRTSCALE*log(lum);
        return((TMbright)(d + .5 - (d < 0.)));
}


int
tmCvLums(                               /* convert luminances using lookup */
TMbright        *ls,
float           *scan,
int             len
)
{
        if (tmFloat2BrtLUT == NULL) {   /* initialize lookup table */
                int32   i;
                tmFloat2BrtLUT = (TMbright *)malloc(sizeof(TMbright)*0x10000);
                if (tmFloat2BrtLUT == NULL)
                        return(TM_E_NOMEM);
                for (i = 0; i < 0x10000; i++) {
                        int32   l = (i<<1 | 1) << 14;
#ifndef isfinite
                        if ((l & 0x7f800000) == 0x7f800000)
                                tmFloat2BrtLUT[i] = TM_NOBRT;
                        else
#endif
                        tmFloat2BrtLUT[i] = tmCvLuminance(*(float *)&l);
                }
        }
        if (len <= 0)
                return(TM_E_OK);
        if ((ls == NULL) | (scan == NULL))
                return(TM_E_ILLEGAL);
        while (len--) {
                if (*scan <= TM_NOLUM) {
                        *ls++ = TM_NOBRT;
                        ++scan;
                        continue;
                }
                *ls++ = tmCvLumLUfp(scan++);
        }
        return(TM_E_OK);
}


int
tmCvGrays(                              /* convert float gray values */
TMstruct        *tms,
TMbright        *ls,
float           *scan,
int             len
)
{
        static const char funcName[] = "tmCvGrays";
        int     i;

        if (tms == NULL)
                returnErr(TM_E_TMINVAL);
        if ((ls == NULL) | (scan == NULL) | (len < 0))
                returnErr(TM_E_ILLEGAL);
        if (tmFloat2BrtLUT == NULL)                     /* initialize */
                tmCvLums(NULL, NULL, 0);
        for (i = len; i--; ) {
                float   lum = tms->inpsf * scan[i];
                if (lum <= TM_NOLUM)
                        ls[i] = TM_NOBRT;
                else
                        ls[i] = tmCvLumLUfp(&lum);
        }
        returnOK;
}


int
tmCvColors(                             /* convert float colors */
TMstruct        *tms,
TMbright        *ls,
BYTE    *cs,
COLOR   *scan,
int     len
)
{
        static const char funcName[] = "tmCvColors";
        static BYTE     gamtab[1024];
        static double   curgam = .0;
        COLOR   cmon;
        float   lum, slum, d;
        int     i;

        if (tms == NULL)
                returnErr(TM_E_TMINVAL);
        if ((ls == NULL) | (scan == NULL) | (len < 0))
                returnErr(TM_E_ILLEGAL);
        if (tmFloat2BrtLUT == NULL)                     /* initialize */
                tmCvLums(NULL, NULL, 0);
        if (cs != TM_NOCHROM && fabs(tms->mongam - curgam) > .02) {
                curgam = tms->mongam;                   /* (re)build table */
                for (i = 1024; i--; )
                        gamtab[i] = (int)(256.*pow((i+.5)/1024., 1./curgam));
        }
        for (i = len; i--; ) {
                if (tmNeedMatrix(tms)) {                /* get monitor RGB */
                        colortrans(cmon, tms->cmat, scan[i]);
                } else {
                        cmon[RED] = tms->inpsf*scan[i][RED];
                        cmon[GRN] = tms->inpsf*scan[i][GRN];
                        cmon[BLU] = tms->inpsf*scan[i][BLU];
                }
#ifdef isfinite
                if (!isfinite(cmon[RED]) || cmon[RED] < .0f) cmon[RED] = .0f;
                if (!isfinite(cmon[GRN]) || cmon[GRN] < .0f) cmon[GRN] = .0f;
                if (!isfinite(cmon[BLU]) || cmon[BLU] < .0f) cmon[BLU] = .0f;
#else
                if (cmon[RED] < .0f) cmon[RED] = .0f;
                if (cmon[GRN] < .0f) cmon[GRN] = .0f;
                if (cmon[BLU] < .0f) cmon[BLU] = .0f;
#endif
                                                        /* world luminance */
                lum =   tms->clf[RED]*cmon[RED] +
                        tms->clf[GRN]*cmon[GRN] +
                        tms->clf[BLU]*cmon[BLU] ;
                if (lum <= TM_NOLUM) {                  /* convert brightness */
                        lum = cmon[RED] = cmon[GRN] = cmon[BLU] = TM_NOLUM;
                        ls[i] = TM_NOBRT;
                } else
                        ls[i] = tmCvLumLUfp(&lum);
                if (cs == TM_NOCHROM)                   /* no color? */
                        continue;
                if (tms->flags & TM_F_MESOPIC && lum < LMESUPPER) {
                        slum = scotlum(cmon);           /* mesopic adj. */
                        if (lum < LMESLOWER) {
                                cmon[RED] = cmon[GRN] = cmon[BLU] = slum;
                        } else {
                                d = (lum - LMESLOWER)/(LMESUPPER - LMESLOWER);
                                if (tms->flags & TM_F_BW)
                                        cmon[RED] = cmon[GRN] =
                                                        cmon[BLU] = d*lum;
                                else
                                        scalecolor(cmon, d);
                                d = (1.f-d)*slum;
                                cmon[RED] += d;
                                cmon[GRN] += d;
                                cmon[BLU] += d;
                        }
                } else if (tms->flags & TM_F_BW) {
                        cmon[RED] = cmon[GRN] = cmon[BLU] = lum;
                }
                d = tms->clf[RED]*cmon[RED]/lum;
                cs[3*i  ] = d>=.999f ? 255 : gamtab[(int)(1024.f*d)];
                d = tms->clf[GRN]*cmon[GRN]/lum;
                cs[3*i+1] = d>=.999f ? 255 : gamtab[(int)(1024.f*d)];
                d = tms->clf[BLU]*cmon[BLU]/lum;
                cs[3*i+2] = d>=.999f ? 255 : gamtab[(int)(1024.f*d)];
        }
        returnOK;
}


int
tmAddHisto(                             /* add values to histogram */
TMstruct        *tms,
TMbright        *ls,
int     len,
int     wt
)
{
        static const char funcName[] = "tmAddHisto";
        int     oldorig=0, oldlen, horig, hlen;
        int     i, j;

        if (tms == NULL)
                returnErr(TM_E_TMINVAL);
        if (len < 0)
                returnErr(TM_E_ILLEGAL);
        if (len == 0)
                returnOK;
                                                /* first, grow limits */
        if (tms->histo == NULL) {
                for (i = len; i-- && ls[i] < MINBRT; )
                        ;
                if (i < 0)
                        returnOK;
                tms->hbrmin = tms->hbrmax = ls[i];
                oldlen = 0;
        } else {
                oldorig = HISTI(tms->hbrmin);
                oldlen = HISTI(tms->hbrmax) + 1 - oldorig;
        }
        for (i = len; i--; ) {
                if ((j = ls[i]) < MINBRT)
                        continue;
                if (j < tms->hbrmin)
                        tms->hbrmin = j;
                else if (j > tms->hbrmax)
                        tms->hbrmax = j;
        }
        horig = HISTI(tms->hbrmin);
        hlen = HISTI(tms->hbrmax) + 1 - horig;
        if (hlen > oldlen) {                    /* (re)allocate histogram */
                int     *newhist = (int *)calloc(hlen, sizeof(int));
                if (newhist == NULL)
                        returnErr(TM_E_NOMEM);
                if (oldlen) {                   /* copy and free old */
                        for (i = oldlen, j = i+oldorig-horig; i; )
                                newhist[--j] = tms->histo[--i];
                        free((MEM_PTR)tms->histo);
                }
                tms->histo = newhist;
        }
        if (wt == 0)
                returnOK;
        for (i = len; i--; )                    /* add in new counts */
                if (ls[i] >= MINBRT)
                        tms->histo[ HISTI(ls[i]) - horig ] += wt;
        returnOK;
}


static double
htcontrs(               /* human threshold contrast sensitivity, dL(La) */
double  La
)
{
        double  l10La, l10dL;
                                /* formula taken from Ferwerda et al. [SG96] */
        if (La < 1.148e-4)
                return(1.38e-3);
        l10La = log10(La);
        if (l10La < -1.44)              /* rod response regime */
                l10dL = pow(.405*l10La + 1.6, 2.18) - 2.86;
        else if (l10La < -.0184)
                l10dL = l10La - .395;
        else if (l10La < 1.9)           /* cone response regime */
                l10dL = pow(.249*l10La + .65, 2.7) - .72;
        else
                l10dL = l10La - 1.255;

        return(exp10(l10dL));
}


int
tmFixedMapping(                 /* compute fixed, linear tone-mapping */
TMstruct        *tms,
double  expmult,
double  gamval
)
{
        static const char funcName[] = "tmFixedMapping";
        double          d;
        int     i;
        
        if (!tmNewMap(tms))
                returnErr(TM_E_NOMEM);
        if (expmult <= .0)
                expmult = 1.;
        if (gamval < MINGAM)
                gamval = tms->mongam;
        d = log(expmult/tms->inpsf);
        for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
                double  val = 256. * exp(
                        ( d + (tms->mbrmin+i)*(1./TM_BRTSCALE) )
                        / gamval);
                tms->lumap[i] = val >= (double)0xffff ? 0xffff : (int)val;
        }
        returnOK;
}


int
tmComputeMapping(                       /* compute histogram tone-mapping */
TMstruct        *tms,
double  gamval,
double  Lddyn,
double  Ldmax
)
{
        static const char funcName[] = "tmComputeMapping";
        int     *histo;
        float   *cumf;
        int     brt0, histlen, threshold, ceiling, trimmings;
        double  logLddyn, Ldmin, Ldavg, Lwavg, Tr, Lw, Ld;
        int32   histot;
        double  sum;
        double  d;
        int     i, j;

        if (tms == NULL || tms->histo == NULL)
                returnErr(TM_E_TMINVAL);
                                        /* check arguments */
        if (Lddyn < MINLDDYN) Lddyn = DEFLDDYN;
        if (Ldmax < MINLDMAX) Ldmax = DEFLDMAX;
        if (gamval < MINGAM) gamval = tms->mongam;
                                        /* compute handy values */
        Ldmin = Ldmax/Lddyn;
        logLddyn = log(Lddyn);
        Ldavg = sqrt(Ldmax*Ldmin);
        i = HISTI(tms->hbrmin);
        brt0 = HISTV(i);
        histlen = HISTI(tms->hbrmax) + 1 - i;
                                        /* histogram total and mean */
        histot = 0; sum = 0;
        j = brt0 + histlen*HISTEP;
        for (i = histlen; i--; ) {
                histot += tms->histo[i];
                sum += (double)(j -= HISTEP) * tms->histo[i];
        }
        threshold = histot*0.005 + .5;
        if (!histot)
                returnErr(TM_E_TMFAIL);
        Lwavg = tmLuminance( (double)sum / histot );
                                        /* use linear tone mapping? */
        if (tms->flags & TM_F_LINEAR || threshold < 4 ||
                        tms->hbrmax - tms->hbrmin < TM_BRTSCALE*logLddyn)
                goto linearmap;
                                        /* clamp histogram */
        histo = (int *)malloc(histlen*sizeof(int));
        cumf = (float *)malloc((histlen+2)*sizeof(float));
        if ((histo == NULL) | (cumf == NULL))
                returnErr(TM_E_NOMEM);
        cumf[histlen+1] = 1.;           /* guard for assignment code */
        for (i = histlen; i--; )        /* make malleable copy */
                histo[i] = tms->histo[i];
        do {                            /* iterate to solution */
                sum = 0;                /* cumulative probability */
                for (i = 0; i < histlen; i++) {
                        cumf[i] = (double)sum/histot;
                        sum += histo[i];
                }
                cumf[histlen] = 1.;
                Tr = histot * (double)(tms->hbrmax - tms->hbrmin) /
                        ((double)histlen*TM_BRTSCALE) / logLddyn;
                ceiling = Tr + 1.;
                trimmings = 0;          /* clip to envelope */
                for (i = histlen; i--; ) {
                        if (tms->flags & TM_F_HCONTR) {
                                Lw = tmLuminance(brt0 + i*HISTEP);
                                Ld = Ldmin * exp( logLddyn *
                                        .5*(cumf[i]+cumf[i+1]) );
                                ceiling = Tr * (htcontrs(Ld) * Lw) /
                                        (htcontrs(Lw) * Ld) + 1.;
                        }
                        if (histo[i] > ceiling) {
                                trimmings += histo[i] - ceiling;
                                histo[i] = ceiling;
                        }
                }
                                        /* check if we're out of data */
                if ((histot -= trimmings) <= threshold) {
                        free((MEM_PTR)histo);
                        free((MEM_PTR)cumf);
                        goto linearmap;
                }
        } while (trimmings > threshold);
                                        /* allocate space for mapping */
        if (!tmNewMap(tms))
                returnErr(TM_E_NOMEM);
                                        /* assign tone-mapping */
        for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
                j = d = (double)i/(tms->mbrmax-tms->mbrmin)*histlen;
                d -= (double)j;
                Ld = Ldmin*exp(logLddyn*((1.-d)*cumf[j]+d*cumf[j+1]));
                d = (Ld - Ldmin)/(Ldmax - Ldmin);
                tms->lumap[i] = 256.*pow(d, 1./gamval);
        }
        free((MEM_PTR)histo);           /* clean up and return */
        free((MEM_PTR)cumf);
        returnOK;
linearmap:                              /* linear tone-mapping */
        if (tms->flags & TM_F_HCONTR)
                d = htcontrs(Ldavg) / htcontrs(Lwavg);
        else
                d = Ldavg / Lwavg;
        return(tmFixedMapping(tms, tms->inpsf*d/Ldmax, gamval));
}


int
tmMapPixels(                    /* apply tone-mapping to pixel(s) */
TMstruct        *tms,
BYTE    *ps,
TMbright        *ls,
BYTE    *cs,
int     len
)
{
        static const char funcName[] = "tmMapPixels";
        int32   li, pv;

        if (tms == NULL || tms->lumap == NULL)
                returnErr(TM_E_TMINVAL);
        if ((ps == NULL) | (ls == NULL) | (len < 0))
                returnErr(TM_E_ILLEGAL);
        while (len--) {
                if ((li = *ls++) < tms->mbrmin) {
                        li = 0;
                } else {
                        if (li > tms->mbrmax)
                                li = tms->mbrmax;
                        li = tms->lumap[li - tms->mbrmin];
                }
                if (cs == TM_NOCHROM)
                        *ps++ = li>255 ? 255 : li;
                else {
                        pv = *cs++ * li / tms->cdiv[RED];
                        *ps++ = pv>255 ? 255 : pv;
                        pv = *cs++ * li / tms->cdiv[GRN];
                        *ps++ = pv>255 ? 255 : pv;
                        pv = *cs++ * li / tms->cdiv[BLU];
                        *ps++ = pv>255 ? 255 : pv;
                }
        }
        returnOK;
}


TMstruct *
tmDup(                          /* duplicate top tone mapping */
TMstruct        *tms
)
{
        int     len;
        int     i;
        TMstruct        *tmnew;

        if (tms == NULL)                /* anything to duplicate? */
                return(NULL);
        tmnew = (TMstruct *)malloc(sizeof(TMstruct));
        if (tmnew == NULL)
                return(NULL);
        *tmnew = *tms;          /* copy everything */
        if (tmnew->histo != NULL) {     /* duplicate histogram */
                len = HISTI(tmnew->hbrmax) + 1 - HISTI(tmnew->hbrmin);
                tmnew->histo = (int *)malloc(len*sizeof(int));
                if (tmnew->histo != NULL)
                        for (i = len; i--; )
                                tmnew->histo[i] = tms->histo[i];
        }
        if (tmnew->lumap != NULL) {     /* duplicate luminance mapping */
                len = tmnew->mbrmax-tmnew->mbrmin+1;
                tmnew->lumap = (unsigned short *)malloc(
                                                len*sizeof(unsigned short) );
                if (tmnew->lumap != NULL)
                        for (i = len; i--; )
                                tmnew->lumap[i] = tms->lumap[i];
        }
                                        /* clear package data */
        for (i = tmNumPkgs; i--; )
                tmnew->pd[i] = NULL;
                                        /* return copy */
        return(tmnew);
}


void
tmDone(tms)                     /* done with tone mapping -- destroy it */
TMstruct        *tms;
{
        int     i;
                                        /* NULL arg. is equiv. to tms */
        if (tms == NULL)
                return;
                                        /* free tables */
        if (tms->histo != NULL)
                free((MEM_PTR)tms->histo);
        if (tms->lumap != NULL)
                free((MEM_PTR)tms->lumap);
                                        /* free private data */
        for (i = tmNumPkgs; i--; )
                if (tms->pd[i] != NULL)
                        (*tmPkg[i]->Free)(tms->pd[i]);
        free((MEM_PTR)tms);             /* free basic structure */
}

/******************** Shared but Private library routines *********************/

BYTE    tmMesofact[BMESUPPER-BMESLOWER];

void
tmMkMesofact()                          /* build mesopic lookup factor table */
{
        int     i;

        if (tmMesofact[BMESUPPER-BMESLOWER-1])
                return;

        for (i = BMESLOWER; i < BMESUPPER; i++)
                tmMesofact[i-BMESLOWER] = 256. *
                                (tmLuminance(i) - LMESLOWER) /
                                (LMESUPPER - LMESLOWER);
}


int
tmNewMap(                       /* allocate new tone-mapping array */
TMstruct        *tms
)
{
        if (tms->lumap != NULL && (tms->mbrmax - tms->mbrmin) !=
                                        (tms->hbrmax - tms->hbrmin)) {
                free((MEM_PTR)tms->lumap);
                tms->lumap = NULL;
        }
        tms->mbrmin = tms->hbrmin;
        tms->mbrmax = tms->hbrmax;
        if (tms->mbrmin > tms->mbrmax)
                return 0;
        if (tms->lumap == NULL)
                tms->lumap = (unsigned short *)malloc(sizeof(unsigned short)*
                                        (tms->mbrmax-tms->mbrmin+1));
        return(tms->lumap != NULL);
}


int
tmErrorReturn(                          /* error return (with message) */
const char      *func,
TMstruct        *tms,
int     err
)
{
        if (tms != NULL) {
                tms->lastFunc = func;
                tms->lastError = err;
                if (tms->flags & TM_F_NOSTDERR)
                        return(err);
        }
        fputs(func, stderr);
        fputs(": ", stderr);
        fputs(tmErrorMessage[err], stderr);
        fputs("!\n", stderr);
        return(err);
}
Revision:	3.35
Committed:	Mon Mar 7 20:49:19 2011 UTC (13 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.34:	+2 -4 lines
Log Message:	Minor improvement in round-off method
#	User	Rev	Content
1	greg	3.1	#ifndef lint
2	greg	3.35	static const char RCSid[] = "$Id: tonemap.c,v 3.34 2009/02/09 20:48:08 greg Exp $";
3	greg	3.1	#endif
4			/*
5			* Tone mapping functions.
6			* See tonemap.h for detailed function descriptions.
7	greg	3.9	* Added von Kries white-balance calculations 10/01 (GW).
8			*
9			* Externals declared in tonemap.h
10			*/
11
12	greg	3.10	#include "copyright.h"
13	greg	3.1
14			#include <stdio.h>
15	greg	3.34	#include <stdlib.h>
16	greg	3.1	#include <math.h>
17			#include "tmprivat.h"
18			#include "tmerrmsg.h"
19
20			#define exp10(x) exp(M_LN10*(x))
21
22	greg	3.4	/* our list of conversion packages */
23			struct tmPackage *tmPkg[TM_MAXPKG];
24			int tmNumPkgs = 0; /* number of registered packages */
25	greg	3.1
26	greg	3.23	/* luminance->brightness lookup */
27	greg	3.24	static TMbright *tmFloat2BrtLUT = NULL;
28	greg	3.23
29			#define tmCvLumLUfp(pf) tmFloat2BrtLUT[(int32 )(pf) >> 15]
30
31	gregl	3.5
32	greg	3.16	TMstruct *
33			tmInit( /* initialize new tone mapping */
34			int flags,
35			RGBPRIMP monpri,
36			double gamval
37			)
38	greg	3.1	{
39			COLORMAT cmat;
40	greg	3.16	TMstruct *tmnew;
41			int i;
42	greg	3.1	/* allocate structure */
43	greg	3.16	tmnew = (TMstruct *)malloc(sizeof(TMstruct));
44	greg	3.1	if (tmnew == NULL)
45			return(NULL);
46
47			tmnew->flags = flags & ~TM_F_UNIMPL;
48	greg	3.15	if (tmnew->flags & TM_F_BW)
49			tmnew->flags &= ~TM_F_MESOPIC;
50	greg	3.1	/* set monitor transform */
51			if (monpri == NULL \|\| monpri == stdprims \|\| tmnew->flags & TM_F_BW) {
52			tmnew->monpri = stdprims;
53			tmnew->clf[RED] = rgb2xyzmat[1][0];
54			tmnew->clf[GRN] = rgb2xyzmat[1][1];
55			tmnew->clf[BLU] = rgb2xyzmat[1][2];
56			} else {
57	greg	3.26	comprgb2xyzmat(cmat, tmnew->monpri=monpri);
58	greg	3.1	tmnew->clf[RED] = cmat[1][0];
59			tmnew->clf[GRN] = cmat[1][1];
60			tmnew->clf[BLU] = cmat[1][2];
61			}
62			/* set gamma value */
63			if (gamval < MINGAM)
64			tmnew->mongam = DEFGAM;
65			else
66			tmnew->mongam = gamval;
67	greg	3.4	/* set color divisors */
68			for (i = 0; i < 3; i++)
69			tmnew->cdiv[i] = 256.*pow(tmnew->clf[i], 1./tmnew->mongam);
70
71	greg	3.1	/* set input transform */
72			tmnew->inppri = tmnew->monpri;
73			tmnew->cmat[0][0] = tmnew->cmat[1][1] = tmnew->cmat[2][2] =
74			tmnew->inpsf = WHTEFFICACY;
75			tmnew->cmat[0][1] = tmnew->cmat[0][2] = tmnew->cmat[1][0] =
76			tmnew->cmat[1][2] = tmnew->cmat[2][0] = tmnew->cmat[2][1] = 0.;
77	greg	3.18	tmnew->inpdat = NULL;
78	greg	3.9	tmnew->hbrmin = 10; tmnew->hbrmax = -10;
79	greg	3.1	tmnew->histo = NULL;
80	greg	3.9	tmnew->mbrmin = 10; tmnew->mbrmax = -10;
81	greg	3.1	tmnew->lumap = NULL;
82	greg	3.4	/* zero private data */
83			for (i = TM_MAXPKG; i--; )
84			tmnew->pd[i] = NULL;
85	greg	3.17	tmnew->lastError = TM_E_OK;
86			tmnew->lastFunc = "NoErr";
87	greg	3.16	/* return new TMstruct */
88			return(tmnew);
89	greg	3.1	}
90
91
92			int
93	greg	3.16	tmSetSpace( /* set input color space for conversions */
94			TMstruct *tms,
95			RGBPRIMP pri,
96	greg	3.18	double sf,
97			MEM_PTR dat
98	greg	3.16	)
99	greg	3.1	{
100	greg	3.17	static const char funcName[] = "tmSetSpace";
101	greg	3.16	int i, j;
102	greg	3.1	/* error check */
103	greg	3.16	if (tms == NULL)
104	greg	3.1	returnErr(TM_E_TMINVAL);
105			if (sf <= 1e-12)
106			returnErr(TM_E_ILLEGAL);
107			/* check if no change */
108	greg	3.18	if (pri == tms->inppri && FEQ(sf, tms->inpsf) && dat == tms->inpdat)
109	greg	3.1	returnOK;
110	greg	3.16	tms->inppri = pri; /* let's set it */
111			tms->inpsf = sf;
112	greg	3.18	tms->inpdat = dat;
113	greg	3.1
114	greg	3.16	if (tms->flags & TM_F_BW) { /* color doesn't matter */
115			tms->monpri = tms->inppri; /* eliminate xform */
116			if (tms->inppri == TM_XYZPRIM) {
117			tms->clf[CIEX] = tms->clf[CIEZ] = 0.;
118			tms->clf[CIEY] = 1.;
119	greg	3.1	} else {
120	greg	3.26	comprgb2xyzmat(tms->cmat, tms->monpri);
121	greg	3.16	tms->clf[RED] = tms->cmat[1][0];
122			tms->clf[GRN] = tms->cmat[1][1];
123			tms->clf[BLU] = tms->cmat[1][2];
124			}
125			tms->cmat[0][0] = tms->cmat[1][1] = tms->cmat[2][2] =
126			tms->inpsf;
127			tms->cmat[0][1] = tms->cmat[0][2] = tms->cmat[1][0] =
128			tms->cmat[1][2] = tms->cmat[2][0] = tms->cmat[2][1] = 0.;
129	greg	3.1
130	greg	3.16	} else if (tms->inppri == TM_XYZPRIM) /* input is XYZ */
131			compxyz2rgbWBmat(tms->cmat, tms->monpri);
132	greg	3.1
133			else { /* input is RGB */
134	greg	3.16	if (tms->inppri != tms->monpri &&
135			PRIMEQ(tms->inppri, tms->monpri))
136			tms->inppri = tms->monpri; /* no xform */
137			comprgb2rgbWBmat(tms->cmat, tms->inppri, tms->monpri);
138	greg	3.1	}
139			for (i = 0; i < 3; i++)
140			for (j = 0; j < 3; j++)
141	greg	3.16	tms->cmat[i][j] *= tms->inpsf;
142	greg	3.4	/* set color divisors */
143			for (i = 0; i < 3; i++)
144	greg	3.16	if (tms->clf[i] > .001)
145			tms->cdiv[i] =
146			256.*pow(tms->clf[i], 1./tms->mongam);
147	greg	3.4	else
148	greg	3.16	tms->cdiv[i] = 1;
149	greg	3.4	/* notify packages */
150			for (i = tmNumPkgs; i--; )
151	greg	3.16	if (tms->pd[i] != NULL && tmPkg[i]->NewSpace != NULL)
152			(*tmPkg[i]->NewSpace)(tms);
153	greg	3.1	returnOK;
154			}
155
156
157			void
158	greg	3.23	tmClearHisto( /* clear current histogram */
159	greg	3.16	TMstruct *tms
160			)
161	greg	3.1	{
162	greg	3.16	if (tms == NULL \|\| tms->histo == NULL)
163	greg	3.1	return;
164	greg	3.16	free((MEM_PTR)tms->histo);
165			tms->histo = NULL;
166	greg	3.1	}
167
168
169	greg	3.23	TMbright
170			tmCvLuminance( /* convert a single luminance */
171			double lum
172			)
173			{
174			double d;
175
176			#ifdef isfinite
177			if (!isfinite(lum) \|\| lum <= TM_NOLUM)
178			#else
179			if (lum <= TM_NOLUM)
180			#endif
181			return(TM_NOBRT);
182			d = TM_BRTSCALE*log(lum);
183	greg	3.35	return((TMbright)(d + .5 - (d < 0.)));
184	greg	3.23	}
185
186
187			int
188			tmCvLums( /* convert luminances using lookup */
189			TMbright *ls,
190			float *scan,
191			int len
192			)
193			{
194			if (tmFloat2BrtLUT == NULL) { /* initialize lookup table */
195			int32 i;
196			tmFloat2BrtLUT = (TMbright )malloc(sizeof(TMbright)0x10000);
197			if (tmFloat2BrtLUT == NULL)
198			return(TM_E_NOMEM);
199			for (i = 0; i < 0x10000; i++) {
200			int32 l = (i<<1 \| 1) << 14;
201			#ifndef isfinite
202			if ((l & 0x7f800000) == 0x7f800000)
203			tmFloat2BrtLUT[i] = TM_NOBRT;
204			else
205			#endif
206			tmFloat2BrtLUT[i] = tmCvLuminance((float )&l);
207			}
208			}
209			if (len <= 0)
210			return(TM_E_OK);
211			if ((ls == NULL) \| (scan == NULL))
212			return(TM_E_ILLEGAL);
213			while (len--) {
214			if (*scan <= TM_NOLUM) {
215			*ls++ = TM_NOBRT;
216			++scan;
217			continue;
218			}
219			*ls++ = tmCvLumLUfp(scan++);
220			}
221			return(TM_E_OK);
222			}
223
224
225			int
226			tmCvGrays( /* convert float gray values */
227			TMstruct *tms,
228			TMbright *ls,
229			float *scan,
230			int len
231			)
232			{
233			static const char funcName[] = "tmCvGrays";
234			int i;
235
236			if (tms == NULL)
237			returnErr(TM_E_TMINVAL);
238			if ((ls == NULL) \| (scan == NULL) \| (len < 0))
239			returnErr(TM_E_ILLEGAL);
240	greg	3.24	if (tmFloat2BrtLUT == NULL) /* initialize */
241			tmCvLums(NULL, NULL, 0);
242	greg	3.23	for (i = len; i--; ) {
243			float lum = tms->inpsf * scan[i];
244			if (lum <= TM_NOLUM)
245			ls[i] = TM_NOBRT;
246			else
247			ls[i] = tmCvLumLUfp(&lum);
248			}
249			returnOK;
250			}
251
252
253	greg	3.1	int
254	greg	3.16	tmCvColors( /* convert float colors */
255			TMstruct *tms,
256			TMbright *ls,
257			BYTE *cs,
258			COLOR *scan,
259			int len
260			)
261	greg	3.1	{
262	greg	3.17	static const char funcName[] = "tmCvColors";
263	greg	3.20	static BYTE gamtab[1024];
264			static double curgam = .0;
265	greg	3.1	COLOR cmon;
266	greg	3.23	float lum, slum, d;
267	greg	3.16	int i;
268	greg	3.1
269	greg	3.16	if (tms == NULL)
270	greg	3.1	returnErr(TM_E_TMINVAL);
271	schorsch	3.13	if ((ls == NULL) \| (scan == NULL) \| (len < 0))
272	greg	3.1	returnErr(TM_E_ILLEGAL);
273	greg	3.24	if (tmFloat2BrtLUT == NULL) /* initialize */
274			tmCvLums(NULL, NULL, 0);
275	greg	3.21	if (cs != TM_NOCHROM && fabs(tms->mongam - curgam) > .02) {
276	greg	3.20	curgam = tms->mongam; /* (re)build table */
277			for (i = 1024; i--; )
278			gamtab[i] = (int)(256.*pow((i+.5)/1024., 1./curgam));
279			}
280	greg	3.1	for (i = len; i--; ) {
281	greg	3.16	if (tmNeedMatrix(tms)) { /* get monitor RGB */
282			colortrans(cmon, tms->cmat, scan[i]);
283	greg	3.15	} else {
284	greg	3.16	cmon[RED] = tms->inpsf*scan[i][RED];
285			cmon[GRN] = tms->inpsf*scan[i][GRN];
286			cmon[BLU] = tms->inpsf*scan[i][BLU];
287	greg	3.1	}
288	greg	3.23	#ifdef isfinite
289			if (!isfinite(cmon[RED]) \|\| cmon[RED] < .0f) cmon[RED] = .0f;
290			if (!isfinite(cmon[GRN]) \|\| cmon[GRN] < .0f) cmon[GRN] = .0f;
291			if (!isfinite(cmon[BLU]) \|\| cmon[BLU] < .0f) cmon[BLU] = .0f;
292			#else
293			if (cmon[RED] < .0f) cmon[RED] = .0f;
294			if (cmon[GRN] < .0f) cmon[GRN] = .0f;
295			if (cmon[BLU] < .0f) cmon[BLU] = .0f;
296	greg	3.22	#endif
297	greg	3.1	/* world luminance */
298	greg	3.16	lum = tms->clf[RED]*cmon[RED] +
299			tms->clf[GRN]*cmon[GRN] +
300			tms->clf[BLU]*cmon[BLU] ;
301	greg	3.25	if (lum <= TM_NOLUM) { /* convert brightness */
302			lum = cmon[RED] = cmon[GRN] = cmon[BLU] = TM_NOLUM;
303	greg	3.23	ls[i] = TM_NOBRT;
304	greg	3.25	} else
305	greg	3.23	ls[i] = tmCvLumLUfp(&lum);
306	greg	3.1	if (cs == TM_NOCHROM) /* no color? */
307			continue;
308	greg	3.16	if (tms->flags & TM_F_MESOPIC && lum < LMESUPPER) {
309	greg	3.1	slum = scotlum(cmon); /* mesopic adj. */
310	greg	3.25	if (lum < LMESLOWER) {
311	greg	3.1	cmon[RED] = cmon[GRN] = cmon[BLU] = slum;
312	greg	3.25	} else {
313	greg	3.1	d = (lum - LMESLOWER)/(LMESUPPER - LMESLOWER);
314	greg	3.16	if (tms->flags & TM_F_BW)
315	greg	3.1	cmon[RED] = cmon[GRN] =
316			cmon[BLU] = d*lum;
317			else
318			scalecolor(cmon, d);
319	greg	3.23	d = (1.f-d)*slum;
320	greg	3.1	cmon[RED] += d;
321			cmon[GRN] += d;
322			cmon[BLU] += d;
323			}
324	greg	3.16	} else if (tms->flags & TM_F_BW) {
325	greg	3.1	cmon[RED] = cmon[GRN] = cmon[BLU] = lum;
326			}
327	greg	3.16	d = tms->clf[RED]*cmon[RED]/lum;
328	greg	3.23	cs[3i ] = d>=.999f ? 255 : gamtab[(int)(1024.fd)];
329	greg	3.16	d = tms->clf[GRN]*cmon[GRN]/lum;
330	greg	3.23	cs[3i+1] = d>=.999f ? 255 : gamtab[(int)(1024.fd)];
331	greg	3.16	d = tms->clf[BLU]*cmon[BLU]/lum;
332	greg	3.23	cs[3i+2] = d>=.999f ? 255 : gamtab[(int)(1024.fd)];
333	greg	3.1	}
334			returnOK;
335			}
336
337
338	greg	3.9	int
339	greg	3.16	tmAddHisto( /* add values to histogram */
340			TMstruct *tms,
341			TMbright *ls,
342			int len,
343			int wt
344			)
345	greg	3.1	{
346	greg	3.17	static const char funcName[] = "tmAddHisto";
347	greg	3.9	int oldorig=0, oldlen, horig, hlen;
348	greg	3.16	int i, j;
349	greg	3.1
350	greg	3.16	if (tms == NULL)
351	greg	3.1	returnErr(TM_E_TMINVAL);
352	gwlarson	3.8	if (len < 0)
353			returnErr(TM_E_ILLEGAL);
354			if (len == 0)
355			returnOK;
356	greg	3.1	/* first, grow limits */
357	greg	3.16	if (tms->histo == NULL) {
358	greg	3.1	for (i = len; i-- && ls[i] < MINBRT; )
359			;
360			if (i < 0)
361			returnOK;
362	greg	3.16	tms->hbrmin = tms->hbrmax = ls[i];
363	greg	3.1	oldlen = 0;
364			} else {
365	greg	3.31	oldorig = HISTI(tms->hbrmin);
366			oldlen = HISTI(tms->hbrmax) + 1 - oldorig;
367	greg	3.1	}
368			for (i = len; i--; ) {
369			if ((j = ls[i]) < MINBRT)
370			continue;
371	greg	3.16	if (j < tms->hbrmin)
372			tms->hbrmin = j;
373			else if (j > tms->hbrmax)
374			tms->hbrmax = j;
375	greg	3.1	}
376	greg	3.31	horig = HISTI(tms->hbrmin);
377			hlen = HISTI(tms->hbrmax) + 1 - horig;
378	greg	3.1	if (hlen > oldlen) { /* (re)allocate histogram */
379	greg	3.16	int newhist = (int )calloc(hlen, sizeof(int));
380	greg	3.1	if (newhist == NULL)
381			returnErr(TM_E_NOMEM);
382			if (oldlen) { /* copy and free old */
383	greg	3.2	for (i = oldlen, j = i+oldorig-horig; i; )
384	greg	3.16	newhist[--j] = tms->histo[--i];
385			free((MEM_PTR)tms->histo);
386	greg	3.1	}
387	greg	3.16	tms->histo = newhist;
388	greg	3.1	}
389			if (wt == 0)
390			returnOK;
391			for (i = len; i--; ) /* add in new counts */
392			if (ls[i] >= MINBRT)
393	greg	3.31	tms->histo[ HISTI(ls[i]) - horig ] += wt;
394	greg	3.1	returnOK;
395			}
396
397
398			static double
399	greg	3.16	htcontrs( /* human threshold contrast sensitivity, dL(La) */
400			double La
401			)
402	greg	3.1	{
403			double l10La, l10dL;
404			/* formula taken from Ferwerda et al. [SG96] */
405			if (La < 1.148e-4)
406			return(1.38e-3);
407			l10La = log10(La);
408			if (l10La < -1.44) /* rod response regime */
409			l10dL = pow(.405*l10La + 1.6, 2.18) - 2.86;
410			else if (l10La < -.0184)
411			l10dL = l10La - .395;
412			else if (l10La < 1.9) /* cone response regime */
413			l10dL = pow(.249*l10La + .65, 2.7) - .72;
414			else
415			l10dL = l10La - 1.255;
416
417			return(exp10(l10dL));
418			}
419
420
421	greg	3.9	int
422	greg	3.16	tmFixedMapping( /* compute fixed, linear tone-mapping */
423			TMstruct *tms,
424			double expmult,
425			double gamval
426			)
427	greg	3.9	{
428	greg	3.17	static const char funcName[] = "tmFixedMapping";
429	greg	3.9	double d;
430	greg	3.16	int i;
431	greg	3.9
432	greg	3.16	if (!tmNewMap(tms))
433	greg	3.9	returnErr(TM_E_NOMEM);
434			if (expmult <= .0)
435			expmult = 1.;
436			if (gamval < MINGAM)
437	greg	3.16	gamval = tms->mongam;
438			d = log(expmult/tms->inpsf);
439	greg	3.28	for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
440			double val = 256. * exp(
441	greg	3.16	( d + (tms->mbrmin+i)*(1./TM_BRTSCALE) )
442	greg	3.28	/ gamval);
443			tms->lumap[i] = val >= (double)0xffff ? 0xffff : (int)val;
444			}
445	greg	3.9	returnOK;
446			}
447
448
449	greg	3.1	int
450	greg	3.16	tmComputeMapping( /* compute histogram tone-mapping */
451			TMstruct *tms,
452			double gamval,
453			double Lddyn,
454			double Ldmax
455			)
456	greg	3.1	{
457	greg	3.17	static const char funcName[] = "tmComputeMapping";
458	greg	3.1	int *histo;
459			float *cumf;
460	greg	3.9	int brt0, histlen, threshold, ceiling, trimmings;
461	greg	3.1	double logLddyn, Ldmin, Ldavg, Lwavg, Tr, Lw, Ld;
462	greg	3.11	int32 histot;
463	greg	3.9	double sum;
464	greg	3.16	double d;
465			int i, j;
466	greg	3.1
467	greg	3.16	if (tms == NULL \|\| tms->histo == NULL)
468	greg	3.1	returnErr(TM_E_TMINVAL);
469			/* check arguments */
470			if (Lddyn < MINLDDYN) Lddyn = DEFLDDYN;
471			if (Ldmax < MINLDMAX) Ldmax = DEFLDMAX;
472	greg	3.16	if (gamval < MINGAM) gamval = tms->mongam;
473	greg	3.1	/* compute handy values */
474			Ldmin = Ldmax/Lddyn;
475			logLddyn = log(Lddyn);
476			Ldavg = sqrt(Ldmax*Ldmin);
477	greg	3.31	i = HISTI(tms->hbrmin);
478	greg	3.32	brt0 = HISTV(i);
479	greg	3.31	histlen = HISTI(tms->hbrmax) + 1 - i;
480	greg	3.1	/* histogram total and mean */
481			histot = 0; sum = 0;
482			j = brt0 + histlen*HISTEP;
483			for (i = histlen; i--; ) {
484	greg	3.16	histot += tms->histo[i];
485	greg	3.30	sum += (double)(j -= HISTEP) * tms->histo[i];
486	greg	3.1	}
487	greg	3.14	threshold = histot*0.005 + .5;
488	greg	3.29	if (!histot)
489	greg	3.1	returnErr(TM_E_TMFAIL);
490			Lwavg = tmLuminance( (double)sum / histot );
491	greg	3.29	/* use linear tone mapping? */
492	greg	3.30	if (tms->flags & TM_F_LINEAR \|\| threshold < 4 \|\|
493			tms->hbrmax - tms->hbrmin < TM_BRTSCALE*logLddyn)
494	greg	3.29	goto linearmap;
495	greg	3.9	/* clamp histogram */
496			histo = (int )malloc(histlensizeof(int));
497			cumf = (float )malloc((histlen+2)sizeof(float));
498	schorsch	3.13	if ((histo == NULL) \| (cumf == NULL))
499	greg	3.9	returnErr(TM_E_NOMEM);
500			cumf[histlen+1] = 1.; /* guard for assignment code */
501			for (i = histlen; i--; ) /* make malleable copy */
502	greg	3.16	histo[i] = tms->histo[i];
503	greg	3.9	do { /* iterate to solution */
504			sum = 0; /* cumulative probability */
505			for (i = 0; i < histlen; i++) {
506			cumf[i] = (double)sum/histot;
507			sum += histo[i];
508			}
509			cumf[histlen] = 1.;
510	greg	3.16	Tr = histot * (double)(tms->hbrmax - tms->hbrmin) /
511	greg	3.9	((double)histlen*TM_BRTSCALE) / logLddyn;
512			ceiling = Tr + 1.;
513			trimmings = 0; /* clip to envelope */
514			for (i = histlen; i--; ) {
515	greg	3.16	if (tms->flags & TM_F_HCONTR) {
516	greg	3.9	Lw = tmLuminance(brt0 + i*HISTEP);
517			Ld = Ldmin * exp( logLddyn *
518			.5*(cumf[i]+cumf[i+1]) );
519			ceiling = Tr * (htcontrs(Ld) * Lw) /
520			(htcontrs(Lw) * Ld) + 1.;
521	greg	3.2	}
522	greg	3.9	if (histo[i] > ceiling) {
523			trimmings += histo[i] - ceiling;
524			histo[i] = ceiling;
525	greg	3.1	}
526			}
527	greg	3.9	/* check if we're out of data */
528			if ((histot -= trimmings) <= threshold) {
529			free((MEM_PTR)histo);
530			free((MEM_PTR)cumf);
531			goto linearmap;
532			}
533			} while (trimmings > threshold);
534	greg	3.30	/* allocate space for mapping */
535			if (!tmNewMap(tms))
536			returnErr(TM_E_NOMEM);
537	greg	3.9	/* assign tone-mapping */
538	greg	3.16	for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
539			j = d = (double)i/(tms->mbrmax-tms->mbrmin)*histlen;
540	greg	3.9	d -= (double)j;
541			Ld = Ldminexp(logLddyn((1.-d)cumf[j]+dcumf[j+1]));
542			d = (Ld - Ldmin)/(Ldmax - Ldmin);
543	greg	3.16	tms->lumap[i] = 256.*pow(d, 1./gamval);
544	greg	3.1	}
545	greg	3.9	free((MEM_PTR)histo); /* clean up and return */
546			free((MEM_PTR)cumf);
547	greg	3.1	returnOK;
548	greg	3.9	linearmap: /* linear tone-mapping */
549	greg	3.16	if (tms->flags & TM_F_HCONTR)
550	greg	3.9	d = htcontrs(Ldavg) / htcontrs(Lwavg);
551			else
552			d = Ldavg / Lwavg;
553	greg	3.16	return(tmFixedMapping(tms, tms->inpsf*d/Ldmax, gamval));
554	greg	3.1	}
555
556
557			int
558	greg	3.16	tmMapPixels( /* apply tone-mapping to pixel(s) */
559			TMstruct *tms,
560			BYTE *ps,
561			TMbright *ls,
562			BYTE *cs,
563			int len
564			)
565	greg	3.1	{
566	greg	3.17	static const char funcName[] = "tmMapPixels";
567	greg	3.16	int32 li, pv;
568	greg	3.1
569	greg	3.16	if (tms == NULL \|\| tms->lumap == NULL)
570	greg	3.1	returnErr(TM_E_TMINVAL);
571	schorsch	3.13	if ((ps == NULL) \| (ls == NULL) \| (len < 0))
572	greg	3.1	returnErr(TM_E_ILLEGAL);
573			while (len--) {
574	greg	3.16	if ((li = *ls++) < tms->mbrmin) {
575	greg	3.9	li = 0;
576			} else {
577	greg	3.16	if (li > tms->mbrmax)
578			li = tms->mbrmax;
579			li = tms->lumap[li - tms->mbrmin];
580	greg	3.9	}
581	greg	3.1	if (cs == TM_NOCHROM)
582			*ps++ = li>255 ? 255 : li;
583			else {
584	greg	3.16	pv = cs++ li / tms->cdiv[RED];
585	greg	3.1	*ps++ = pv>255 ? 255 : pv;
586	greg	3.16	pv = cs++ li / tms->cdiv[GRN];
587	greg	3.1	*ps++ = pv>255 ? 255 : pv;
588	greg	3.16	pv = cs++ li / tms->cdiv[BLU];
589	greg	3.1	*ps++ = pv>255 ? 255 : pv;
590			}
591			}
592			returnOK;
593			}
594
595
596	greg	3.16	TMstruct *
597			tmDup( /* duplicate top tone mapping */
598			TMstruct *tms
599			)
600	greg	3.3	{
601			int len;
602	greg	3.16	int i;
603			TMstruct *tmnew;
604	greg	3.3
605	greg	3.16	if (tms == NULL) /* anything to duplicate? */
606	greg	3.3	return(NULL);
607	greg	3.16	tmnew = (TMstruct *)malloc(sizeof(TMstruct));
608	greg	3.3	if (tmnew == NULL)
609			return(NULL);
610	greg	3.16	tmnew = tms; /* copy everything */
611	greg	3.3	if (tmnew->histo != NULL) { /* duplicate histogram */
612	greg	3.31	len = HISTI(tmnew->hbrmax) + 1 - HISTI(tmnew->hbrmin);
613	greg	3.3	tmnew->histo = (int )malloc(lensizeof(int));
614			if (tmnew->histo != NULL)
615			for (i = len; i--; )
616	greg	3.16	tmnew->histo[i] = tms->histo[i];
617	greg	3.3	}
618			if (tmnew->lumap != NULL) { /* duplicate luminance mapping */
619	gregl	3.6	len = tmnew->mbrmax-tmnew->mbrmin+1;
620	greg	3.3	tmnew->lumap = (unsigned short *)malloc(
621			len*sizeof(unsigned short) );
622			if (tmnew->lumap != NULL)
623			for (i = len; i--; )
624	greg	3.16	tmnew->lumap[i] = tms->lumap[i];
625	greg	3.3	}
626	greg	3.4	/* clear package data */
627			for (i = tmNumPkgs; i--; )
628			tmnew->pd[i] = NULL;
629	greg	3.16	/* return copy */
630			return(tmnew);
631	greg	3.1	}
632
633
634			void
635			tmDone(tms) /* done with tone mapping -- destroy it */
636	greg	3.16	TMstruct *tms;
637	greg	3.1	{
638	greg	3.16	int i;
639			/* NULL arg. is equiv. to tms */
640			if (tms == NULL)
641	greg	3.1	return;
642			/* free tables */
643			if (tms->histo != NULL)
644	greg	3.4	free((MEM_PTR)tms->histo);
645	greg	3.1	if (tms->lumap != NULL)
646	greg	3.4	free((MEM_PTR)tms->lumap);
647			/* free private data */
648			for (i = tmNumPkgs; i--; )
649			if (tms->pd[i] != NULL)
650			(*tmPkg[i]->Free)(tms->pd[i]);
651			free((MEM_PTR)tms); /* free basic structure */
652	greg	3.9	}
653
654			/****************** Shared but Private library routines *******************/
655
656			BYTE tmMesofact[BMESUPPER-BMESLOWER];
657
658			void
659			tmMkMesofact() /* build mesopic lookup factor table */
660			{
661	greg	3.16	int i;
662	greg	3.9
663			if (tmMesofact[BMESUPPER-BMESLOWER-1])
664			return;
665
666			for (i = BMESLOWER; i < BMESUPPER; i++)
667			tmMesofact[i-BMESLOWER] = 256. *
668			(tmLuminance(i) - LMESLOWER) /
669			(LMESUPPER - LMESLOWER);
670			}
671
672
673			int
674	greg	3.33	tmNewMap( /* allocate new tone-mapping array */
675			TMstruct *tms
676			)
677			{
678			if (tms->lumap != NULL && (tms->mbrmax - tms->mbrmin) !=
679			(tms->hbrmax - tms->hbrmin)) {
680			free((MEM_PTR)tms->lumap);
681			tms->lumap = NULL;
682			}
683			tms->mbrmin = tms->hbrmin;
684			tms->mbrmax = tms->hbrmax;
685			if (tms->mbrmin > tms->mbrmax)
686			return 0;
687			if (tms->lumap == NULL)
688			tms->lumap = (unsigned short )malloc(sizeof(unsigned short)
689			(tms->mbrmax-tms->mbrmin+1));
690			return(tms->lumap != NULL);
691			}
692
693
694			int
695	greg	3.16	tmErrorReturn( /* error return (with message) */
696	greg	3.17	const char *func,
697	greg	3.16	TMstruct *tms,
698			int err
699			)
700	greg	3.9	{
701	greg	3.17	if (tms != NULL) {
702			tms->lastFunc = func;
703			tms->lastError = err;
704			if (tms->flags & TM_F_NOSTDERR)
705			return(err);
706			}
707	greg	3.9	fputs(func, stderr);
708			fputs(": ", stderr);
709			fputs(tmErrorMessage[err], stderr);
710			fputs("!\n", stderr);
711			return(err);
712	greg	3.1	}