src/common/tonemap.c

#ifndef lint
static const char       RCSid[] = "$Id: tonemap.c,v 3.49 2021/04/12 22:16:02 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        <string.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] = TM_BRES*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] = 1.;
                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 */
                if (!comprgb2rgbWBmat(tms->cmat, tms->inppri, tms->monpri))
                        returnErr(TM_E_ILLEGAL);
        }
        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++)
                tms->cdiv[i] = TM_BRES*pow(tms->clf[i] < .001 ? .001 :
                                                tms->clf[i], 1./tms->mongam);
                                                /* 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(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,
uby8    *cs,
COLOR   *scan,
int     len
)
{
        static const char funcName[] = "tmCvColors";
        static uby8     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 */
                HIST_TYP  *newhist = (HIST_TYP *)calloc(hlen, sizeof(HIST_TYP));
                if (newhist == NULL)
                        returnErr(TM_E_NOMEM);
                if (oldlen) {                   /* copy and free old */
                        memcpy(newhist+(oldorig-horig),
                                        tms->histo, oldlen*sizeof(HIST_TYP));
                        free(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,
double  Lddyn
)
{
        static const char funcName[] = "tmFixedMapping";
        const int       maxV = (1L<<(8*sizeof(TMAP_TYP))) - 1;
        double          minD;
        int             i;
        
        if (!tmNewMap(tms))
                returnErr(TM_E_NOMEM);
                                        /* check arguments */
        if (expmult <= .0) expmult = 1.;
        if (gamval < MINGAM) gamval = tms->mongam;
        if (Lddyn < MINLDDYN) Lddyn = DEFLDDYN;
        minD = 1./Lddyn;
        for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
                double  d;
                d = expmult/tms->inpsf * tmLuminance(tms->mbrmin + i);
                if (d >= 2.*minD)
                        d -= minD;
                else                    /* soft black crushing */
                        d *= d/(4.*minD);
                d /= 1. - minD;
                d = TM_BRES*pow(d, 1./gamval);
                tms->lumap[i] = (d > maxV) ? maxV : (int)d;
        }
        returnOK;
}


int
tmComputeMapping(                       /* compute histogram tone-mapping */
TMstruct        *tms,
double  gamval,
double  Lddyn,
double  Ldmax
)
{
        static const char funcName[] = "tmComputeMapping";
        HIST_TYP        *histo;
        float   *cumf;
        int     brt0, histlen;
        HIST_TYP        threshold, ceiling, trimmings, histot;
        double  logLddyn, Ldmin, Lwavg, Tr, Lw, Ld;
        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);
        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];
        }
        if (!histot)
                returnErr(TM_E_TMFAIL);
        threshold = histot/40 + 1;
        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 = (HIST_TYP *)malloc(histlen*sizeof(HIST_TYP));
        cumf = (float *)malloc((histlen+2)*sizeof(float));
        if ((histo == NULL) | (cumf == NULL))
                returnErr(TM_E_NOMEM);
        cumf[histlen+1] = 1.;           /* guard for assignment code */
                                        /* make malleable copy */
        memcpy(histo, tms->histo, histlen*sizeof(HIST_TYP));
        do {                            /* iterate to solution */
                sum = 0;                /* cumulative probability */
                for (i = 0; i < histlen; i++) {
                        cumf[i] = sum/histot;
                        sum += (double)histo[i];
                }
                cumf[histlen] = 1.;
                Tr = histot * (double)(tms->hbrmax - tms->hbrmin) /
                                ((double)TM_BRTSCALE*histlen*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(histo);
                        free(cumf);
                        goto linearmap;
                }
        } while (40*trimmings > histot);
                                        /* 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] = TM_BRES*pow(d, 1./gamval);
        }
        free(histo);                    /* clean up and return */
        free(cumf);
        returnOK;
linearmap:                              /* linear tone-mapping */
        if (tms->flags & TM_F_HCONTR)
                d = htcontrs(sqrt(Ldmax*Ldmin)) / htcontrs(Lwavg);
        else
                d = Ldmax / tmLuminance(tms->hbrmax);
        return(tmFixedMapping(tms, tms->inpsf*d/Ldmax, gamval, Lddyn));
}


int
tmMapPixels(                    /* apply tone-mapping to pixel(s) */
TMstruct        *tms,
uby8    *ps,
TMbright        *ls,
uby8    *cs,
int     len
)
{
        static const char funcName[] = "tmMapPixels";
        TMbright        lv;
        TMAP_TYP        li;
        int             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 ((lv = *ls++) < tms->mbrmin) {
                        li = 0;
                } else {
                        if (lv > tms->mbrmax)
                                lv = tms->mbrmax;
                        li = tms->lumap[lv - tms->mbrmin];
                }
                if (cs == TM_NOCHROM) {
#if !(TM_BRES & 0xff)
                        *ps++ = li>=TM_BRES ? 255 : li/(TM_BRES>>8);
#else
                        *ps++ = li>=TM_BRES ? 255 : (li<<8)/TM_BRES;
#endif
                } 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 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 = (HIST_TYP *)malloc(len*sizeof(HIST_TYP));
                if (tmnew->histo != NULL)
                        memcpy(tmnew->histo, tms->histo, len*sizeof(HIST_TYP));
        }
        if (tmnew->lumap != NULL) {     /* duplicate luminance mapping */
                len = tmnew->mbrmax-tmnew->mbrmin+1;
                tmnew->lumap = (TMAP_TYP *)malloc(len*sizeof(TMAP_TYP));
                if (tmnew->lumap != NULL)
                        memcpy(tmnew->lumap, tms->lumap, len*sizeof(TMAP_TYP));
        }
                                        /* 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(tms->histo);
        if (tms->lumap != NULL)
                free(tms->lumap);
                                        /* free private data */
        for (i = tmNumPkgs; i--; )
                if (tms->pd[i] != NULL)
                        (*tmPkg[i]->Free)(tms->pd[i]);
        free(tms);                      /* free basic structure */
}

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

uby8    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(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 = (TMAP_TYP *)calloc(tms->mbrmax-tms->mbrmin+1,
                                                sizeof(TMAP_TYP));
        else
                memset(tms->lumap, 0, (tms->mbrmax-tms->mbrmin+1)*sizeof(TMAP_TYP));

        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:	3.50
Committed:	Tue Apr 13 02:42:31 2021 UTC (3 years ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.49:	+3 -5 lines
Log Message:	Added better termination criterion for linear tone curve