src/common/tonemap.c

#ifndef lint
static const char       RCSid[] = "$Id: tonemap.c,v 3.23 2006/05/10 15:21:58 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        <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 {
                comprgb2xyzWBmat(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 {
                        comprgb2xyzWBmat(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);
        if (d > 0.)
                return((TMbright)(d+.5));
        return((TMbright)(d-.5));
}


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";
        double  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);
        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 COLOR    csmall = {.5*MINLUM, .5*MINLUM, .5*MINLUM};
        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 */
                        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 = (tms->hbrmin-MINBRT)/HISTEP;
                oldlen = (tms->hbrmax-MINBRT)/HISTEP + 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 = (tms->hbrmin-MINBRT)/HISTEP;
        hlen = (tms->hbrmax-MINBRT)/HISTEP + 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[ (ls[i]-MINBRT)/HISTEP - 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));
}


static 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
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--; )
                tms->lumap[i] = 256. * exp(
                        ( d + (tms->mbrmin+i)*(1./TM_BRTSCALE) )
                        / gamval );
        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 = (tms->hbrmin-MINBRT)/HISTEP;
        brt0 = MINBRT + HISTEP/2 + i*HISTEP;
        histlen = (tms->hbrmax-MINBRT)/HISTEP + 1 - i;
                                        /* histogram total and mean */
        histot = 0; sum = 0;
        j = brt0 + histlen*HISTEP;
        for (i = histlen; i--; ) {
                histot += tms->histo[i];
                sum += (j -= HISTEP) * tms->histo[i];
        }
        threshold = histot*0.005 + .5;
        if (threshold < 4)
                returnErr(TM_E_TMFAIL);
        Lwavg = tmLuminance( (double)sum / histot );
                                        /* allocate space for mapping */
        if (!tmNewMap(tms))
                returnErr(TM_E_NOMEM);
                                        /* use linear tone mapping? */
        if (tms->flags & TM_F_LINEAR)
                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);
                                        /* 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 = (tmnew->hbrmax-MINBRT)/HISTEP + 1 -
                                (tmnew->hbrmin-MINBRT)/HISTEP;
                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
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:	3.24
Committed:	Wed May 10 15:34:17 2006 UTC (17 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.23:	+6 -3 lines
Log Message:	Minor fixes to last change with IEEE float lookup function
#	User	Rev	Content
1	greg	3.1	#ifndef lint
2	greg	3.24	static const char RCSid[] = "$Id: tonemap.c,v 3.23 2006/05/10 15:21:58 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			#include <math.h>
16			#include "tmprivat.h"
17			#include "tmerrmsg.h"
18
19			#define exp10(x) exp(M_LN10*(x))
20
21	greg	3.4	/* our list of conversion packages */
22			struct tmPackage *tmPkg[TM_MAXPKG];
23			int tmNumPkgs = 0; /* number of registered packages */
24	greg	3.1
25	greg	3.23	/* luminance->brightness lookup */
26	greg	3.24	static TMbright *tmFloat2BrtLUT = NULL;
27	greg	3.23
28			#define tmCvLumLUfp(pf) tmFloat2BrtLUT[(int32 )(pf) >> 15]
29
30	gregl	3.5
31	greg	3.16	TMstruct *
32			tmInit( /* initialize new tone mapping */
33			int flags,
34			RGBPRIMP monpri,
35			double gamval
36			)
37	greg	3.1	{
38			COLORMAT cmat;
39	greg	3.16	TMstruct *tmnew;
40			int i;
41	greg	3.1	/* allocate structure */
42	greg	3.16	tmnew = (TMstruct *)malloc(sizeof(TMstruct));
43	greg	3.1	if (tmnew == NULL)
44			return(NULL);
45
46			tmnew->flags = flags & ~TM_F_UNIMPL;
47	greg	3.15	if (tmnew->flags & TM_F_BW)
48			tmnew->flags &= ~TM_F_MESOPIC;
49	greg	3.1	/* set monitor transform */
50			if (monpri == NULL \|\| monpri == stdprims \|\| tmnew->flags & TM_F_BW) {
51			tmnew->monpri = stdprims;
52			tmnew->clf[RED] = rgb2xyzmat[1][0];
53			tmnew->clf[GRN] = rgb2xyzmat[1][1];
54			tmnew->clf[BLU] = rgb2xyzmat[1][2];
55			} else {
56	greg	3.9	comprgb2xyzWBmat(cmat, tmnew->monpri=monpri);
57	greg	3.1	tmnew->clf[RED] = cmat[1][0];
58			tmnew->clf[GRN] = cmat[1][1];
59			tmnew->clf[BLU] = cmat[1][2];
60			}
61			/* set gamma value */
62			if (gamval < MINGAM)
63			tmnew->mongam = DEFGAM;
64			else
65			tmnew->mongam = gamval;
66	greg	3.4	/* set color divisors */
67			for (i = 0; i < 3; i++)
68			tmnew->cdiv[i] = 256.*pow(tmnew->clf[i], 1./tmnew->mongam);
69
70	greg	3.1	/* set input transform */
71			tmnew->inppri = tmnew->monpri;
72			tmnew->cmat[0][0] = tmnew->cmat[1][1] = tmnew->cmat[2][2] =
73			tmnew->inpsf = WHTEFFICACY;
74			tmnew->cmat[0][1] = tmnew->cmat[0][2] = tmnew->cmat[1][0] =
75			tmnew->cmat[1][2] = tmnew->cmat[2][0] = tmnew->cmat[2][1] = 0.;
76	greg	3.18	tmnew->inpdat = NULL;
77	greg	3.9	tmnew->hbrmin = 10; tmnew->hbrmax = -10;
78	greg	3.1	tmnew->histo = NULL;
79	greg	3.9	tmnew->mbrmin = 10; tmnew->mbrmax = -10;
80	greg	3.1	tmnew->lumap = NULL;
81	greg	3.4	/* zero private data */
82			for (i = TM_MAXPKG; i--; )
83			tmnew->pd[i] = NULL;
84	greg	3.17	tmnew->lastError = TM_E_OK;
85			tmnew->lastFunc = "NoErr";
86	greg	3.16	/* return new TMstruct */
87			return(tmnew);
88	greg	3.1	}
89
90
91			int
92	greg	3.16	tmSetSpace( /* set input color space for conversions */
93			TMstruct *tms,
94			RGBPRIMP pri,
95	greg	3.18	double sf,
96			MEM_PTR dat
97	greg	3.16	)
98	greg	3.1	{
99	greg	3.17	static const char funcName[] = "tmSetSpace";
100	greg	3.16	int i, j;
101	greg	3.1	/* error check */
102	greg	3.16	if (tms == NULL)
103	greg	3.1	returnErr(TM_E_TMINVAL);
104			if (sf <= 1e-12)
105			returnErr(TM_E_ILLEGAL);
106			/* check if no change */
107	greg	3.18	if (pri == tms->inppri && FEQ(sf, tms->inpsf) && dat == tms->inpdat)
108	greg	3.1	returnOK;
109	greg	3.16	tms->inppri = pri; /* let's set it */
110			tms->inpsf = sf;
111	greg	3.18	tms->inpdat = dat;
112	greg	3.1
113	greg	3.16	if (tms->flags & TM_F_BW) { /* color doesn't matter */
114			tms->monpri = tms->inppri; /* eliminate xform */
115			if (tms->inppri == TM_XYZPRIM) {
116			tms->clf[CIEX] = tms->clf[CIEZ] = 0.;
117			tms->clf[CIEY] = 1.;
118	greg	3.1	} else {
119	greg	3.16	comprgb2xyzWBmat(tms->cmat, tms->monpri);
120			tms->clf[RED] = tms->cmat[1][0];
121			tms->clf[GRN] = tms->cmat[1][1];
122			tms->clf[BLU] = tms->cmat[1][2];
123			}
124			tms->cmat[0][0] = tms->cmat[1][1] = tms->cmat[2][2] =
125			tms->inpsf;
126			tms->cmat[0][1] = tms->cmat[0][2] = tms->cmat[1][0] =
127			tms->cmat[1][2] = tms->cmat[2][0] = tms->cmat[2][1] = 0.;
128	greg	3.1
129	greg	3.16	} else if (tms->inppri == TM_XYZPRIM) /* input is XYZ */
130			compxyz2rgbWBmat(tms->cmat, tms->monpri);
131	greg	3.1
132			else { /* input is RGB */
133	greg	3.16	if (tms->inppri != tms->monpri &&
134			PRIMEQ(tms->inppri, tms->monpri))
135			tms->inppri = tms->monpri; /* no xform */
136			comprgb2rgbWBmat(tms->cmat, tms->inppri, tms->monpri);
137	greg	3.1	}
138			for (i = 0; i < 3; i++)
139			for (j = 0; j < 3; j++)
140	greg	3.16	tms->cmat[i][j] *= tms->inpsf;
141	greg	3.4	/* set color divisors */
142			for (i = 0; i < 3; i++)
143	greg	3.16	if (tms->clf[i] > .001)
144			tms->cdiv[i] =
145			256.*pow(tms->clf[i], 1./tms->mongam);
146	greg	3.4	else
147	greg	3.16	tms->cdiv[i] = 1;
148	greg	3.4	/* notify packages */
149			for (i = tmNumPkgs; i--; )
150	greg	3.16	if (tms->pd[i] != NULL && tmPkg[i]->NewSpace != NULL)
151			(*tmPkg[i]->NewSpace)(tms);
152	greg	3.1	returnOK;
153			}
154
155
156			void
157	greg	3.23	tmClearHisto( /* clear current histogram */
158	greg	3.16	TMstruct *tms
159			)
160	greg	3.1	{
161	greg	3.16	if (tms == NULL \|\| tms->histo == NULL)
162	greg	3.1	return;
163	greg	3.16	free((MEM_PTR)tms->histo);
164			tms->histo = NULL;
165	greg	3.1	}
166
167
168	greg	3.23	TMbright
169			tmCvLuminance( /* convert a single luminance */
170			double lum
171			)
172			{
173			double d;
174
175			#ifdef isfinite
176			if (!isfinite(lum) \|\| lum <= TM_NOLUM)
177			#else
178			if (lum <= TM_NOLUM)
179			#endif
180			return(TM_NOBRT);
181			d = TM_BRTSCALE*log(lum);
182			if (d > 0.)
183			return((TMbright)(d+.5));
184			return((TMbright)(d-.5));
185			}
186
187
188			int
189			tmCvLums( /* convert luminances using lookup */
190			TMbright *ls,
191			float *scan,
192			int len
193			)
194			{
195			if (tmFloat2BrtLUT == NULL) { /* initialize lookup table */
196			int32 i;
197			tmFloat2BrtLUT = (TMbright )malloc(sizeof(TMbright)0x10000);
198			if (tmFloat2BrtLUT == NULL)
199			return(TM_E_NOMEM);
200			for (i = 0; i < 0x10000; i++) {
201			int32 l = (i<<1 \| 1) << 14;
202			#ifndef isfinite
203			if ((l & 0x7f800000) == 0x7f800000)
204			tmFloat2BrtLUT[i] = TM_NOBRT;
205			else
206			#endif
207			tmFloat2BrtLUT[i] = tmCvLuminance((float )&l);
208			}
209			}
210			if (len <= 0)
211			return(TM_E_OK);
212			if ((ls == NULL) \| (scan == NULL))
213			return(TM_E_ILLEGAL);
214			while (len--) {
215			if (*scan <= TM_NOLUM) {
216			*ls++ = TM_NOBRT;
217			++scan;
218			continue;
219			}
220			*ls++ = tmCvLumLUfp(scan++);
221			}
222			return(TM_E_OK);
223			}
224
225
226			int
227			tmCvGrays( /* convert float gray values */
228			TMstruct *tms,
229			TMbright *ls,
230			float *scan,
231			int len
232			)
233			{
234			static const char funcName[] = "tmCvGrays";
235			double d;
236			int i;
237
238			if (tms == NULL)
239			returnErr(TM_E_TMINVAL);
240			if ((ls == NULL) \| (scan == NULL) \| (len < 0))
241			returnErr(TM_E_ILLEGAL);
242	greg	3.24	if (tmFloat2BrtLUT == NULL) /* initialize */
243			tmCvLums(NULL, NULL, 0);
244	greg	3.23	for (i = len; i--; ) {
245			float lum = tms->inpsf * scan[i];
246			if (lum <= TM_NOLUM)
247			ls[i] = TM_NOBRT;
248			else
249			ls[i] = tmCvLumLUfp(&lum);
250			}
251			returnOK;
252			}
253
254
255	greg	3.1	int
256	greg	3.16	tmCvColors( /* convert float colors */
257			TMstruct *tms,
258			TMbright *ls,
259			BYTE *cs,
260			COLOR *scan,
261			int len
262			)
263	greg	3.1	{
264	greg	3.17	static const char funcName[] = "tmCvColors";
265	greg	3.12	static COLOR csmall = {.5MINLUM, .5MINLUM, .5*MINLUM};
266	greg	3.20	static BYTE gamtab[1024];
267			static double curgam = .0;
268	greg	3.1	COLOR cmon;
269	greg	3.23	float lum, slum, d;
270	greg	3.16	int i;
271	greg	3.1
272	greg	3.16	if (tms == NULL)
273	greg	3.1	returnErr(TM_E_TMINVAL);
274	schorsch	3.13	if ((ls == NULL) \| (scan == NULL) \| (len < 0))
275	greg	3.1	returnErr(TM_E_ILLEGAL);
276	greg	3.24	if (tmFloat2BrtLUT == NULL) /* initialize */
277			tmCvLums(NULL, NULL, 0);
278	greg	3.21	if (cs != TM_NOCHROM && fabs(tms->mongam - curgam) > .02) {
279	greg	3.20	curgam = tms->mongam; /* (re)build table */
280			for (i = 1024; i--; )
281			gamtab[i] = (int)(256.*pow((i+.5)/1024., 1./curgam));
282			}
283	greg	3.1	for (i = len; i--; ) {
284	greg	3.16	if (tmNeedMatrix(tms)) { /* get monitor RGB */
285			colortrans(cmon, tms->cmat, scan[i]);
286	greg	3.15	} else {
287	greg	3.16	cmon[RED] = tms->inpsf*scan[i][RED];
288			cmon[GRN] = tms->inpsf*scan[i][GRN];
289			cmon[BLU] = tms->inpsf*scan[i][BLU];
290	greg	3.1	}
291	greg	3.23	#ifdef isfinite
292			if (!isfinite(cmon[RED]) \|\| cmon[RED] < .0f) cmon[RED] = .0f;
293			if (!isfinite(cmon[GRN]) \|\| cmon[GRN] < .0f) cmon[GRN] = .0f;
294			if (!isfinite(cmon[BLU]) \|\| cmon[BLU] < .0f) cmon[BLU] = .0f;
295			#else
296			if (cmon[RED] < .0f) cmon[RED] = .0f;
297			if (cmon[GRN] < .0f) cmon[GRN] = .0f;
298			if (cmon[BLU] < .0f) cmon[BLU] = .0f;
299	greg	3.22	#endif
300	greg	3.1	/* world luminance */
301	greg	3.16	lum = tms->clf[RED]*cmon[RED] +
302			tms->clf[GRN]*cmon[GRN] +
303			tms->clf[BLU]*cmon[BLU] ;
304	greg	3.23	if (lum <= TM_NOLUM) /* convert brightness */
305			ls[i] = TM_NOBRT;
306			else
307			ls[i] = tmCvLumLUfp(&lum);
308	greg	3.1	if (cs == TM_NOCHROM) /* no color? */
309			continue;
310	greg	3.16	if (tms->flags & TM_F_MESOPIC && lum < LMESUPPER) {
311	greg	3.1	slum = scotlum(cmon); /* mesopic adj. */
312			if (lum < LMESLOWER)
313			cmon[RED] = cmon[GRN] = cmon[BLU] = slum;
314			else {
315			d = (lum - LMESLOWER)/(LMESUPPER - LMESLOWER);
316	greg	3.16	if (tms->flags & TM_F_BW)
317	greg	3.1	cmon[RED] = cmon[GRN] =
318			cmon[BLU] = d*lum;
319			else
320			scalecolor(cmon, d);
321	greg	3.23	d = (1.f-d)*slum;
322	greg	3.1	cmon[RED] += d;
323			cmon[GRN] += d;
324			cmon[BLU] += d;
325			}
326	greg	3.16	} else if (tms->flags & TM_F_BW) {
327	greg	3.1	cmon[RED] = cmon[GRN] = cmon[BLU] = lum;
328			}
329	greg	3.16	d = tms->clf[RED]*cmon[RED]/lum;
330	greg	3.23	cs[3i ] = d>=.999f ? 255 : gamtab[(int)(1024.fd)];
331	greg	3.16	d = tms->clf[GRN]*cmon[GRN]/lum;
332	greg	3.23	cs[3i+1] = d>=.999f ? 255 : gamtab[(int)(1024.fd)];
333	greg	3.16	d = tms->clf[BLU]*cmon[BLU]/lum;
334	greg	3.23	cs[3i+2] = d>=.999f ? 255 : gamtab[(int)(1024.fd)];
335	greg	3.1	}
336			returnOK;
337			}
338
339
340	greg	3.9	int
341	greg	3.16	tmAddHisto( /* add values to histogram */
342			TMstruct *tms,
343			TMbright *ls,
344			int len,
345			int wt
346			)
347	greg	3.1	{
348	greg	3.17	static const char funcName[] = "tmAddHisto";
349	greg	3.9	int oldorig=0, oldlen, horig, hlen;
350	greg	3.16	int i, j;
351	greg	3.1
352	greg	3.16	if (tms == NULL)
353	greg	3.1	returnErr(TM_E_TMINVAL);
354	gwlarson	3.8	if (len < 0)
355			returnErr(TM_E_ILLEGAL);
356			if (len == 0)
357			returnOK;
358	greg	3.1	/* first, grow limits */
359	greg	3.16	if (tms->histo == NULL) {
360	greg	3.1	for (i = len; i-- && ls[i] < MINBRT; )
361			;
362			if (i < 0)
363			returnOK;
364	greg	3.16	tms->hbrmin = tms->hbrmax = ls[i];
365	greg	3.1	oldlen = 0;
366			} else {
367	greg	3.16	oldorig = (tms->hbrmin-MINBRT)/HISTEP;
368			oldlen = (tms->hbrmax-MINBRT)/HISTEP + 1 - oldorig;
369	greg	3.1	}
370			for (i = len; i--; ) {
371			if ((j = ls[i]) < MINBRT)
372			continue;
373	greg	3.16	if (j < tms->hbrmin)
374			tms->hbrmin = j;
375			else if (j > tms->hbrmax)
376			tms->hbrmax = j;
377	greg	3.1	}
378	greg	3.16	horig = (tms->hbrmin-MINBRT)/HISTEP;
379			hlen = (tms->hbrmax-MINBRT)/HISTEP + 1 - horig;
380	greg	3.1	if (hlen > oldlen) { /* (re)allocate histogram */
381	greg	3.16	int newhist = (int )calloc(hlen, sizeof(int));
382	greg	3.1	if (newhist == NULL)
383			returnErr(TM_E_NOMEM);
384			if (oldlen) { /* copy and free old */
385	greg	3.2	for (i = oldlen, j = i+oldorig-horig; i; )
386	greg	3.16	newhist[--j] = tms->histo[--i];
387			free((MEM_PTR)tms->histo);
388	greg	3.1	}
389	greg	3.16	tms->histo = newhist;
390	greg	3.1	}
391			if (wt == 0)
392			returnOK;
393			for (i = len; i--; ) /* add in new counts */
394			if (ls[i] >= MINBRT)
395	greg	3.16	tms->histo[ (ls[i]-MINBRT)/HISTEP - horig ] += wt;
396	greg	3.1	returnOK;
397			}
398
399
400			static double
401	greg	3.16	htcontrs( /* human threshold contrast sensitivity, dL(La) */
402			double La
403			)
404	greg	3.1	{
405			double l10La, l10dL;
406			/* formula taken from Ferwerda et al. [SG96] */
407			if (La < 1.148e-4)
408			return(1.38e-3);
409			l10La = log10(La);
410			if (l10La < -1.44) /* rod response regime */
411			l10dL = pow(.405*l10La + 1.6, 2.18) - 2.86;
412			else if (l10La < -.0184)
413			l10dL = l10La - .395;
414			else if (l10La < 1.9) /* cone response regime */
415			l10dL = pow(.249*l10La + .65, 2.7) - .72;
416			else
417			l10dL = l10La - 1.255;
418
419			return(exp10(l10dL));
420			}
421
422
423	greg	3.9	static int
424	greg	3.16	tmNewMap( /* allocate new tone-mapping array */
425			TMstruct *tms
426			)
427	greg	3.9	{
428	greg	3.16	if (tms->lumap != NULL && (tms->mbrmax - tms->mbrmin) !=
429			(tms->hbrmax - tms->hbrmin)) {
430			free((MEM_PTR)tms->lumap);
431			tms->lumap = NULL;
432			}
433			tms->mbrmin = tms->hbrmin;
434			tms->mbrmax = tms->hbrmax;
435			if (tms->mbrmin > tms->mbrmax)
436	greg	3.9	return 0;
437	greg	3.16	if (tms->lumap == NULL)
438			tms->lumap = (unsigned short )malloc(sizeof(unsigned short)
439			(tms->mbrmax-tms->mbrmin+1));
440			return(tms->lumap != NULL);
441	greg	3.9	}
442
443
444			int
445	greg	3.16	tmFixedMapping( /* compute fixed, linear tone-mapping */
446			TMstruct *tms,
447			double expmult,
448			double gamval
449			)
450	greg	3.9	{
451	greg	3.17	static const char funcName[] = "tmFixedMapping";
452	greg	3.9	double d;
453	greg	3.16	int i;
454	greg	3.9
455	greg	3.16	if (!tmNewMap(tms))
456	greg	3.9	returnErr(TM_E_NOMEM);
457			if (expmult <= .0)
458			expmult = 1.;
459			if (gamval < MINGAM)
460	greg	3.16	gamval = tms->mongam;
461			d = log(expmult/tms->inpsf);
462			for (i = tms->mbrmax-tms->mbrmin+1; i--; )
463			tms->lumap[i] = 256. * exp(
464			( d + (tms->mbrmin+i)*(1./TM_BRTSCALE) )
465	greg	3.9	/ gamval );
466			returnOK;
467			}
468
469
470	greg	3.1	int
471	greg	3.16	tmComputeMapping( /* compute histogram tone-mapping */
472			TMstruct *tms,
473			double gamval,
474			double Lddyn,
475			double Ldmax
476			)
477	greg	3.1	{
478	greg	3.17	static const char funcName[] = "tmComputeMapping";
479	greg	3.1	int *histo;
480			float *cumf;
481	greg	3.9	int brt0, histlen, threshold, ceiling, trimmings;
482	greg	3.1	double logLddyn, Ldmin, Ldavg, Lwavg, Tr, Lw, Ld;
483	greg	3.11	int32 histot;
484	greg	3.9	double sum;
485	greg	3.16	double d;
486			int i, j;
487	greg	3.1
488	greg	3.16	if (tms == NULL \|\| tms->histo == NULL)
489	greg	3.1	returnErr(TM_E_TMINVAL);
490			/* check arguments */
491			if (Lddyn < MINLDDYN) Lddyn = DEFLDDYN;
492			if (Ldmax < MINLDMAX) Ldmax = DEFLDMAX;
493	greg	3.16	if (gamval < MINGAM) gamval = tms->mongam;
494	greg	3.1	/* compute handy values */
495			Ldmin = Ldmax/Lddyn;
496			logLddyn = log(Lddyn);
497			Ldavg = sqrt(Ldmax*Ldmin);
498	greg	3.16	i = (tms->hbrmin-MINBRT)/HISTEP;
499	greg	3.1	brt0 = MINBRT + HISTEP/2 + i*HISTEP;
500	greg	3.16	histlen = (tms->hbrmax-MINBRT)/HISTEP + 1 - i;
501	greg	3.1	/* histogram total and mean */
502			histot = 0; sum = 0;
503			j = brt0 + histlen*HISTEP;
504			for (i = histlen; i--; ) {
505	greg	3.16	histot += tms->histo[i];
506			sum += (j -= HISTEP) * tms->histo[i];
507	greg	3.1	}
508	greg	3.14	threshold = histot*0.005 + .5;
509	greg	3.1	if (threshold < 4)
510			returnErr(TM_E_TMFAIL);
511			Lwavg = tmLuminance( (double)sum / histot );
512	greg	3.9	/* allocate space for mapping */
513	greg	3.16	if (!tmNewMap(tms))
514	greg	3.9	returnErr(TM_E_NOMEM);
515			/* use linear tone mapping? */
516	greg	3.16	if (tms->flags & TM_F_LINEAR)
517	greg	3.9	goto linearmap;
518			/* clamp histogram */
519			histo = (int )malloc(histlensizeof(int));
520			cumf = (float )malloc((histlen+2)sizeof(float));
521	schorsch	3.13	if ((histo == NULL) \| (cumf == NULL))
522	greg	3.9	returnErr(TM_E_NOMEM);
523			cumf[histlen+1] = 1.; /* guard for assignment code */
524			for (i = histlen; i--; ) /* make malleable copy */
525	greg	3.16	histo[i] = tms->histo[i];
526	greg	3.9	do { /* iterate to solution */
527			sum = 0; /* cumulative probability */
528			for (i = 0; i < histlen; i++) {
529			cumf[i] = (double)sum/histot;
530			sum += histo[i];
531			}
532			cumf[histlen] = 1.;
533	greg	3.16	Tr = histot * (double)(tms->hbrmax - tms->hbrmin) /
534	greg	3.9	((double)histlen*TM_BRTSCALE) / logLddyn;
535			ceiling = Tr + 1.;
536			trimmings = 0; /* clip to envelope */
537			for (i = histlen; i--; ) {
538	greg	3.16	if (tms->flags & TM_F_HCONTR) {
539	greg	3.9	Lw = tmLuminance(brt0 + i*HISTEP);
540			Ld = Ldmin * exp( logLddyn *
541			.5*(cumf[i]+cumf[i+1]) );
542			ceiling = Tr * (htcontrs(Ld) * Lw) /
543			(htcontrs(Lw) * Ld) + 1.;
544	greg	3.2	}
545	greg	3.9	if (histo[i] > ceiling) {
546			trimmings += histo[i] - ceiling;
547			histo[i] = ceiling;
548	greg	3.1	}
549			}
550	greg	3.9	/* check if we're out of data */
551			if ((histot -= trimmings) <= threshold) {
552			free((MEM_PTR)histo);
553			free((MEM_PTR)cumf);
554			goto linearmap;
555			}
556			} while (trimmings > threshold);
557			/* assign tone-mapping */
558	greg	3.16	for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
559			j = d = (double)i/(tms->mbrmax-tms->mbrmin)*histlen;
560	greg	3.9	d -= (double)j;
561			Ld = Ldminexp(logLddyn((1.-d)cumf[j]+dcumf[j+1]));
562			d = (Ld - Ldmin)/(Ldmax - Ldmin);
563	greg	3.16	tms->lumap[i] = 256.*pow(d, 1./gamval);
564	greg	3.1	}
565	greg	3.9	free((MEM_PTR)histo); /* clean up and return */
566			free((MEM_PTR)cumf);
567	greg	3.1	returnOK;
568	greg	3.9	linearmap: /* linear tone-mapping */
569	greg	3.16	if (tms->flags & TM_F_HCONTR)
570	greg	3.9	d = htcontrs(Ldavg) / htcontrs(Lwavg);
571			else
572			d = Ldavg / Lwavg;
573	greg	3.16	return(tmFixedMapping(tms, tms->inpsf*d/Ldmax, gamval));
574	greg	3.1	}
575
576
577			int
578	greg	3.16	tmMapPixels( /* apply tone-mapping to pixel(s) */
579			TMstruct *tms,
580			BYTE *ps,
581			TMbright *ls,
582			BYTE *cs,
583			int len
584			)
585	greg	3.1	{
586	greg	3.17	static const char funcName[] = "tmMapPixels";
587	greg	3.16	int32 li, pv;
588	greg	3.1
589	greg	3.16	if (tms == NULL \|\| tms->lumap == NULL)
590	greg	3.1	returnErr(TM_E_TMINVAL);
591	schorsch	3.13	if ((ps == NULL) \| (ls == NULL) \| (len < 0))
592	greg	3.1	returnErr(TM_E_ILLEGAL);
593			while (len--) {
594	greg	3.16	if ((li = *ls++) < tms->mbrmin) {
595	greg	3.9	li = 0;
596			} else {
597	greg	3.16	if (li > tms->mbrmax)
598			li = tms->mbrmax;
599			li = tms->lumap[li - tms->mbrmin];
600	greg	3.9	}
601	greg	3.1	if (cs == TM_NOCHROM)
602			*ps++ = li>255 ? 255 : li;
603			else {
604	greg	3.16	pv = cs++ li / tms->cdiv[RED];
605	greg	3.1	*ps++ = pv>255 ? 255 : pv;
606	greg	3.16	pv = cs++ li / tms->cdiv[GRN];
607	greg	3.1	*ps++ = pv>255 ? 255 : pv;
608	greg	3.16	pv = cs++ li / tms->cdiv[BLU];
609	greg	3.1	*ps++ = pv>255 ? 255 : pv;
610			}
611			}
612			returnOK;
613			}
614
615
616
617
618	greg	3.16	TMstruct *
619			tmDup( /* duplicate top tone mapping */
620			TMstruct *tms
621			)
622	greg	3.3	{
623			int len;
624	greg	3.16	int i;
625			TMstruct *tmnew;
626	greg	3.3
627	greg	3.16	if (tms == NULL) /* anything to duplicate? */
628	greg	3.3	return(NULL);
629	greg	3.16	tmnew = (TMstruct *)malloc(sizeof(TMstruct));
630	greg	3.3	if (tmnew == NULL)
631			return(NULL);
632	greg	3.16	tmnew = tms; /* copy everything */
633	greg	3.3	if (tmnew->histo != NULL) { /* duplicate histogram */
634	gregl	3.6	len = (tmnew->hbrmax-MINBRT)/HISTEP + 1 -
635			(tmnew->hbrmin-MINBRT)/HISTEP;
636	greg	3.3	tmnew->histo = (int )malloc(lensizeof(int));
637			if (tmnew->histo != NULL)
638			for (i = len; i--; )
639	greg	3.16	tmnew->histo[i] = tms->histo[i];
640	greg	3.3	}
641			if (tmnew->lumap != NULL) { /* duplicate luminance mapping */
642	gregl	3.6	len = tmnew->mbrmax-tmnew->mbrmin+1;
643	greg	3.3	tmnew->lumap = (unsigned short *)malloc(
644			len*sizeof(unsigned short) );
645			if (tmnew->lumap != NULL)
646			for (i = len; i--; )
647	greg	3.16	tmnew->lumap[i] = tms->lumap[i];
648	greg	3.3	}
649	greg	3.4	/* clear package data */
650			for (i = tmNumPkgs; i--; )
651			tmnew->pd[i] = NULL;
652	greg	3.16	/* return copy */
653			return(tmnew);
654	greg	3.1	}
655
656
657			void
658			tmDone(tms) /* done with tone mapping -- destroy it */
659	greg	3.16	TMstruct *tms;
660	greg	3.1	{
661	greg	3.16	int i;
662			/* NULL arg. is equiv. to tms */
663			if (tms == NULL)
664	greg	3.1	return;
665			/* free tables */
666			if (tms->histo != NULL)
667	greg	3.4	free((MEM_PTR)tms->histo);
668	greg	3.1	if (tms->lumap != NULL)
669	greg	3.4	free((MEM_PTR)tms->lumap);
670			/* free private data */
671			for (i = tmNumPkgs; i--; )
672			if (tms->pd[i] != NULL)
673			(*tmPkg[i]->Free)(tms->pd[i]);
674			free((MEM_PTR)tms); /* free basic structure */
675	greg	3.9	}
676
677			/****************** Shared but Private library routines *******************/
678
679			BYTE tmMesofact[BMESUPPER-BMESLOWER];
680
681			void
682			tmMkMesofact() /* build mesopic lookup factor table */
683			{
684	greg	3.16	int i;
685	greg	3.9
686			if (tmMesofact[BMESUPPER-BMESLOWER-1])
687			return;
688
689			for (i = BMESLOWER; i < BMESUPPER; i++)
690			tmMesofact[i-BMESLOWER] = 256. *
691			(tmLuminance(i) - LMESLOWER) /
692			(LMESUPPER - LMESLOWER);
693			}
694
695
696			int
697	greg	3.16	tmErrorReturn( /* error return (with message) */
698	greg	3.17	const char *func,
699	greg	3.16	TMstruct *tms,
700			int err
701			)
702	greg	3.9	{
703	greg	3.17	if (tms != NULL) {
704			tms->lastFunc = func;
705			tms->lastError = err;
706			if (tms->flags & TM_F_NOSTDERR)
707			return(err);
708			}
709	greg	3.9	fputs(func, stderr);
710			fputs(": ", stderr);
711			fputs(tmErrorMessage[err], stderr);
712			fputs("!\n", stderr);
713			return(err);
714	greg	3.1	}