src/px/pcond3.c

/* Copyright (c) 1997 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 * Routines for computing and applying brightness mapping.
 */

#include "pcond.h"


#define CVRATIO         0.025           /* fraction of samples allowed > env. */

#define exp10(x)        exp(2.302585093*(x))

float   modhist[HISTRES];               /* modified histogram */
double  mhistot;                        /* modified histogram total */
float   cumf[HISTRES+1];                /* cumulative distribution function */


getfixations(fp)                /* load fixation history list */
FILE    *fp;
{
#define FIXHUNK         128
        RESOLU  fvres;
        int     pos[2];
        register int    px, py, i;
                                /* initialize our resolution struct */
        if ((fvres.or=inpres.or)&YMAJOR) {
                fvres.xr = fvxr;
                fvres.yr = fvyr;
        } else {
                fvres.xr = fvyr;
                fvres.yr = fvxr;
        }
                                /* read each picture position */
        while (fscanf(fp, "%d %d", &pos[0], &pos[1]) == 2) {
                                /* convert to closest index in foveal image */
                loc2pix(pos, &fvres,
                                (pos[0]+.5)/inpres.xr, (pos[1]+.5)/inpres.yr);
                                /* include nine neighborhood samples */
                for (px = pos[0]-1; px <= pos[0]+1; px++) {
                        if (px < 0 || px >= fvxr)
                                continue;
                        for (py = pos[1]-1; py <= pos[1]+1; py++) {
                                if (py < 0 || py >= fvyr)
                                        continue;
                                for (i = nfixations; i-- > 0; )
                                        if (fixlst[i][0] == px &&
                                                        fixlst[i][1] == py)
                                                break;
                                if (i >= 0)
                                        continue;       /* already there */
                                if (nfixations % FIXHUNK == 0) {
                                        if (nfixations)
                                                fixlst = (short (*)[2])
                                                        realloc((char *)fixlst,
                                                        (nfixations+FIXHUNK)*
                                                        2*sizeof(short));
                                        else
                                                fixlst = (short (*)[2])malloc(
                                                        FIXHUNK*2*sizeof(short)
                                                        );
                                        if (fixlst == NULL)
                                                syserror("malloc");
                                }
                                fixlst[nfixations][0] = px;
                                fixlst[nfixations][1] = py;
                                nfixations++;
                        }
                }
        }
        if (!feof(fp)) {
                fprintf(stderr, "%s: format error reading fixation data\n",
                                progname);
                exit(1);
        }
#undef  FIXHUNK
}


double
centprob(x, y)                  /* center-weighting probability function */
int     x, y;
{
        double  xr, yr, p;
                                /* paraboloid, 0 at 90 degrees from center */
        xr = (x - .5*(fvxr-1))/90.;     /* 180 degree fisheye has fv?r == 90 */
        yr = (y - .5*(fvyr-1))/90.;
        p = 1. - xr*xr - yr*yr;
        return(p < 0. ? 0. : p);
}


comphist()                      /* create foveal sampling histogram */
{
        double  l, b, w, lwmin, lwmax;
        register int    x, y;

        lwmin = 1e10;                   /* find extrema */
        lwmax = 0.;
        for (y = 0; y < fvyr; y++)
                for (x = 0; x < fvxr; x++) {
                        l = plum(fovscan(y)[x]);
                        if (l < lwmin) lwmin = l;
                        if (l > lwmax) lwmax = l;
                }
        lwmin -= FTINY;
        lwmax += FTINY;
        if (lwmin < LMIN) lwmin = LMIN;
        if (lwmax > LMAX) lwmax = LMAX;
        bwmin = Bl(lwmin);
        bwmax = Bl(lwmax);
                                        /* (re)compute histogram */
        bwavg = 0.;
        histot = 0.;
        for (x = 0; x < HISTRES; x++)
                bwhist[x] = 0.;
                                        /* global average */
        if (!(what2do&DO_FIXHIST) || fixfrac < 1.-FTINY)
                for (y = 0; y < fvyr; y++)
                        for (x = 0; x < fvxr; x++) {
                                l = plum(fovscan(y)[x]);
                                if (l < lwmin) continue;
                                if (l > lwmax) continue;
                                b = Bl(l);
                                bwavg += b;
                                w = what2do&DO_CWEIGHT ? centprob(x,y) : 1.;
                                bwhist[bwhi(b)] += w;
                                histot += w;
                        }
                                        /* average fixation points */
        if (what2do&DO_FIXHIST && nfixations > 0) {
                if (histot > FTINY)
                        w = fixfrac/(1.-fixfrac)*histot/nfixations;
                else
                        w = 1.;
                for (x = 0; x < nfixations; x++) {
                        l = plum(fovscan(fixlst[x][1])[fixlst[x][0]]);
                        if (l < lwmin) continue;
                        if (l > lwmax) continue;
                        b = Bl(l);
                        bwavg += b;
                        bwhist[bwhi(b)] += w;
                        histot += w;
                }
        }
        bwavg /= histot;
}


mkcumf()                        /* make cumulative distribution function */
{
        register int    i;
        register double sum;

        mhistot = 0.;           /* compute modified total */
        for (i = 0; i < HISTRES; i++)
                mhistot += modhist[i];

        sum = 0.;               /* compute cumulative function */
        for (i = 0; i < HISTRES; i++) {
                cumf[i] = sum/mhistot;
                sum += modhist[i];
        }
        cumf[HISTRES] = 1.;
}


double
cf(b)                           /* return cumulative function at b */
double  b;
{
        double  x;
        register int    i;

        i = x = HISTRES*(b - bwmin)/(bwmax - bwmin);
        x -= (double)i;
        return(cumf[i]*(1.-x) + cumf[i+1]*x);
}


double
BLw(Lw)                         /* map world luminance to display brightness */
double  Lw;
{
        double  b;

        if (Lw <= LMIN || (b = Bl(Lw)) <= bwmin+FTINY)
                return(Bldmin);
        if (b >= bwmax-FTINY)
                return(Bldmax);
        return(Bldmin + cf(b)*(Bldmax-Bldmin));
}


double
htcontrs(La)            /* 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));
}


double
clampf(Lw)              /* derivative clamping function */
double  Lw;
{
        double  bLw, ratio;

        bLw = BLw(Lw);          /* apply current brightness map */
        ratio = what2do&DO_HSENS ? htcontrs(Lb(bLw))/htcontrs(Lw) : Lb(bLw)/Lw;
        return(ratio/(Lb1(bLw)*(Bldmax-Bldmin)*Bl1(Lw)));
}


int
mkbrmap()                       /* make dynamic range map */
{
        double  T, b, s;
        double  ceiling, trimmings;
        register int    i;
                                        /* copy initial histogram */
        bcopy((char *)bwhist, (char *)modhist, sizeof(modhist));
        s = (bwmax - bwmin)/HISTRES;
                                        /* loop until satisfactory */
        do {
                mkcumf();                       /* sync brightness mapping */
                if (mhistot <= histot*CVRATIO)
                        return(-1);             /* no compression needed! */
                T = mhistot * (bwmax - bwmin) / HISTRES;
                trimmings = 0.;                 /* clip to envelope */
                for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) {
                        ceiling = T*clampf(Lb(b));
                        if (modhist[i] > ceiling) {
                                trimmings += modhist[i] - ceiling;
                                modhist[i] = ceiling;
                        }
                }
        } while (trimmings > histot*CVRATIO);

        return(0);                      /* we got it */
}


scotscan(scan, xres)            /* apply scotopic color sensitivity loss */
COLOR   *scan;
int     xres;
{
        COLOR   ctmp;
        double  incolor, b, Lw;
        register int    i;

        for (i = 0; i < xres; i++) {
                Lw = plum(scan[i]);
                if (Lw >= TopMesopic)
                        incolor = 1.;
                else if (Lw <= BotMesopic)
                        incolor = 0.;
                else
                        incolor = (Lw - BotMesopic) /
                                        (TopMesopic - BotMesopic);
                if (incolor < 1.-FTINY) {
                        b = (1.-incolor)*slum(scan[i])*inpexp/SWNORM;
                        if (lumf == rgblum) b /= WHTEFFICACY;
                        setcolor(ctmp, b, b, b);
                        if (incolor <= FTINY)
                                setcolor(scan[i], 0., 0., 0.);
                        else
                                scalecolor(scan[i], incolor);
                        addcolor(scan[i], ctmp);
                }
        }
}


mapscan(scan, xres)             /* apply tone mapping operator to scanline */
COLOR   *scan;
int     xres;
{
        double  mult, Lw, b;
        register int    i;

        for (i = 0; i < xres; i++) {
                Lw = plum(scan[i]);
                if (Lw < LMIN) {
                        setcolor(scan[i], 0., 0., 0.);
                        continue;
                }
                b = BLw(Lw);
                mult = (Lb(b) - ldmin)/(ldmax - ldmin) / (Lw*inpexp);
                if (lumf == rgblum) mult *= WHTEFFICACY;
                scalecolor(scan[i], mult);
        }
}


putmapping(fp)                  /* put out mapping function */
FILE    *fp;
{
        double  b, s;
        register int    i;
        double  wlum, sf, dlum;

        sf = scalef*inpexp;
        if (lumf == cielum) sf *= WHTEFFICACY;
        s = (bwmax - bwmin)/HISTRES;
        for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) {
                wlum = Lb(b);
                if (what2do&DO_LINEAR) {
                        dlum = sf*wlum;
                        if (dlum > ldmax) dlum = ldmax;
                        else if (dlum < ldmin) dlum = ldmin;
                        fprintf(fp, "%e %e\n", wlum, dlum);
                } else
                        fprintf(fp, "%e %e\n", wlum, Lb(BLw(wlum)));
        }
}
Revision:	3.8
Committed:	Wed Jan 29 13:22:13 1997 UTC (27 years, 3 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.7:	+131 -0 lines
Log Message:	added -i option to take fixation points on standard input
#	User	Rev	Content
1	greg	3.7	/* Copyright (c) 1997 Regents of the University of California */
2	greg	3.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* Routines for computing and applying brightness mapping.
9			*/
10
11			#include "pcond.h"
12
13
14	greg	3.5	#define CVRATIO 0.025 /* fraction of samples allowed > env. */
15	greg	3.1
16			#define exp10(x) exp(2.302585093*(x))
17
18	greg	3.5	float modhist[HISTRES]; /* modified histogram */
19			double mhistot; /* modified histogram total */
20	greg	3.1	float cumf[HISTRES+1]; /* cumulative distribution function */
21
22
23	greg	3.8	getfixations(fp) /* load fixation history list */
24			FILE *fp;
25			{
26			#define FIXHUNK 128
27			RESOLU fvres;
28			int pos[2];
29			register int px, py, i;
30			/* initialize our resolution struct */
31			if ((fvres.or=inpres.or)&YMAJOR) {
32			fvres.xr = fvxr;
33			fvres.yr = fvyr;
34			} else {
35			fvres.xr = fvyr;
36			fvres.yr = fvxr;
37			}
38			/* read each picture position */
39			while (fscanf(fp, "%d %d", &pos[0], &pos[1]) == 2) {
40			/* convert to closest index in foveal image */
41			loc2pix(pos, &fvres,
42			(pos[0]+.5)/inpres.xr, (pos[1]+.5)/inpres.yr);
43			/* include nine neighborhood samples */
44			for (px = pos[0]-1; px <= pos[0]+1; px++) {
45			if (px < 0 \|\| px >= fvxr)
46			continue;
47			for (py = pos[1]-1; py <= pos[1]+1; py++) {
48			if (py < 0 \|\| py >= fvyr)
49			continue;
50			for (i = nfixations; i-- > 0; )
51			if (fixlst[i][0] == px &&
52			fixlst[i][1] == py)
53			break;
54			if (i >= 0)
55			continue; /* already there */
56			if (nfixations % FIXHUNK == 0) {
57			if (nfixations)
58			fixlst = (short (*)[2])
59			realloc((char *)fixlst,
60			(nfixations+FIXHUNK)*
61			2*sizeof(short));
62			else
63			fixlst = (short (*)[2])malloc(
64			FIXHUNK2sizeof(short)
65			);
66			if (fixlst == NULL)
67			syserror("malloc");
68			}
69			fixlst[nfixations][0] = px;
70			fixlst[nfixations][1] = py;
71			nfixations++;
72			}
73			}
74			}
75			if (!feof(fp)) {
76			fprintf(stderr, "%s: format error reading fixation data\n",
77			progname);
78			exit(1);
79			}
80			#undef FIXHUNK
81			}
82
83
84			double
85			centprob(x, y) /* center-weighting probability function */
86			int x, y;
87			{
88			double xr, yr, p;
89			/* paraboloid, 0 at 90 degrees from center */
90			xr = (x - .5(fvxr-1))/90.; / 180 degree fisheye has fv?r == 90 */
91			yr = (y - .5*(fvyr-1))/90.;
92			p = 1. - xrxr - yryr;
93			return(p < 0. ? 0. : p);
94			}
95
96
97			comphist() /* create foveal sampling histogram */
98			{
99			double l, b, w, lwmin, lwmax;
100			register int x, y;
101
102			lwmin = 1e10; /* find extrema */
103			lwmax = 0.;
104			for (y = 0; y < fvyr; y++)
105			for (x = 0; x < fvxr; x++) {
106			l = plum(fovscan(y)[x]);
107			if (l < lwmin) lwmin = l;
108			if (l > lwmax) lwmax = l;
109			}
110			lwmin -= FTINY;
111			lwmax += FTINY;
112			if (lwmin < LMIN) lwmin = LMIN;
113			if (lwmax > LMAX) lwmax = LMAX;
114			bwmin = Bl(lwmin);
115			bwmax = Bl(lwmax);
116			/* (re)compute histogram */
117			bwavg = 0.;
118			histot = 0.;
119			for (x = 0; x < HISTRES; x++)
120			bwhist[x] = 0.;
121			/* global average */
122			if (!(what2do&DO_FIXHIST) \|\| fixfrac < 1.-FTINY)
123			for (y = 0; y < fvyr; y++)
124			for (x = 0; x < fvxr; x++) {
125			l = plum(fovscan(y)[x]);
126			if (l < lwmin) continue;
127			if (l > lwmax) continue;
128			b = Bl(l);
129			bwavg += b;
130			w = what2do&DO_CWEIGHT ? centprob(x,y) : 1.;
131			bwhist[bwhi(b)] += w;
132			histot += w;
133			}
134			/* average fixation points */
135			if (what2do&DO_FIXHIST && nfixations > 0) {
136			if (histot > FTINY)
137			w = fixfrac/(1.-fixfrac)*histot/nfixations;
138			else
139			w = 1.;
140			for (x = 0; x < nfixations; x++) {
141			l = plum(fovscan(fixlst[x][1])[fixlst[x][0]]);
142			if (l < lwmin) continue;
143			if (l > lwmax) continue;
144			b = Bl(l);
145			bwavg += b;
146			bwhist[bwhi(b)] += w;
147			histot += w;
148			}
149			}
150			bwavg /= histot;
151			}
152
153
154	greg	3.1	mkcumf() /* make cumulative distribution function */
155			{
156			register int i;
157	greg	3.5	register double sum;
158	greg	3.1
159	greg	3.5	mhistot = 0.; /* compute modified total */
160			for (i = 0; i < HISTRES; i++)
161			mhistot += modhist[i];
162
163			sum = 0.; /* compute cumulative function */
164			for (i = 0; i < HISTRES; i++) {
165			cumf[i] = sum/mhistot;
166	greg	3.1	sum += modhist[i];
167			}
168			cumf[HISTRES] = 1.;
169			}
170
171
172			double
173			cf(b) /* return cumulative function at b */
174			double b;
175			{
176			double x;
177			register int i;
178
179			i = x = HISTRES*(b - bwmin)/(bwmax - bwmin);
180			x -= (double)i;
181			return(cumf[i](1.-x) + cumf[i+1]x);
182			}
183
184
185			double
186			BLw(Lw) /* map world luminance to display brightness */
187			double Lw;
188			{
189			double b;
190
191			if (Lw <= LMIN \|\| (b = Bl(Lw)) <= bwmin+FTINY)
192			return(Bldmin);
193			if (b >= bwmax-FTINY)
194			return(Bldmax);
195	greg	3.4	return(Bldmin + cf(b)*(Bldmax-Bldmin));
196	greg	3.1	}
197
198
199			double
200			htcontrs(La) /* human threshold contrast sensitivity, dL(La) */
201			double La;
202			{
203			double l10La, l10dL;
204			/* formula taken from Ferwerda et al. [SG96] */
205			if (La < 1.148e-4)
206			return(1.38e-3);
207			l10La = log10(La);
208			if (l10La < -1.44) /* rod response regime */
209			l10dL = pow(.405*l10La + 1.6, 2.18) - 2.86;
210			else if (l10La < -.0184)
211			l10dL = l10La - .395;
212			else if (l10La < 1.9) /* cone response regime */
213			l10dL = pow(.249*l10La + .65, 2.7) - .72;
214			else
215			l10dL = l10La - 1.255;
216
217			return(exp10(l10dL));
218			}
219
220
221			double
222			clampf(Lw) /* derivative clamping function */
223			double Lw;
224			{
225			double bLw, ratio;
226
227			bLw = BLw(Lw); /* apply current brightness map */
228			ratio = what2do&DO_HSENS ? htcontrs(Lb(bLw))/htcontrs(Lw) : Lb(bLw)/Lw;
229			return(ratio/(Lb1(bLw)(Bldmax-Bldmin)Bl1(Lw)));
230			}
231
232
233			int
234			mkbrmap() /* make dynamic range map */
235			{
236			double T, b, s;
237	greg	3.5	double ceiling, trimmings;
238	greg	3.1	register int i;
239			/* copy initial histogram */
240	greg	3.5	bcopy((char )bwhist, (char )modhist, sizeof(modhist));
241	greg	3.1	s = (bwmax - bwmin)/HISTRES;
242			/* loop until satisfactory */
243	greg	3.5	do {
244			mkcumf(); /* sync brightness mapping */
245			if (mhistot <= histot*CVRATIO)
246			return(-1); /* no compression needed! */
247			T = mhistot * (bwmax - bwmin) / HISTRES;
248			trimmings = 0.; /* clip to envelope */
249	greg	3.1	for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) {
250	greg	3.5	ceiling = T*clampf(Lb(b));
251			if (modhist[i] > ceiling) {
252			trimmings += modhist[i] - ceiling;
253			modhist[i] = ceiling;
254			}
255	greg	3.1	}
256	greg	3.5	} while (trimmings > histot*CVRATIO);
257
258			return(0); /* we got it */
259	greg	3.1	}
260
261
262			scotscan(scan, xres) /* apply scotopic color sensitivity loss */
263			COLOR *scan;
264			int xres;
265			{
266			COLOR ctmp;
267			double incolor, b, Lw;
268			register int i;
269
270			for (i = 0; i < xres; i++) {
271			Lw = plum(scan[i]);
272			if (Lw >= TopMesopic)
273			incolor = 1.;
274			else if (Lw <= BotMesopic)
275			incolor = 0.;
276			else
277			incolor = (Lw - BotMesopic) /
278			(TopMesopic - BotMesopic);
279			if (incolor < 1.-FTINY) {
280	greg	3.2	b = (1.-incolor)slum(scan[i])inpexp/SWNORM;
281			if (lumf == rgblum) b /= WHTEFFICACY;
282			setcolor(ctmp, b, b, b);
283	greg	3.1	if (incolor <= FTINY)
284			setcolor(scan[i], 0., 0., 0.);
285			else
286			scalecolor(scan[i], incolor);
287			addcolor(scan[i], ctmp);
288			}
289			}
290			}
291
292
293			mapscan(scan, xres) /* apply tone mapping operator to scanline */
294			COLOR *scan;
295			int xres;
296			{
297			double mult, Lw, b;
298			register int i;
299
300			for (i = 0; i < xres; i++) {
301			Lw = plum(scan[i]);
302			if (Lw < LMIN) {
303			setcolor(scan[i], 0., 0., 0.);
304			continue;
305			}
306			b = BLw(Lw);
307			mult = (Lb(b) - ldmin)/(ldmax - ldmin) / (Lw*inpexp);
308			if (lumf == rgblum) mult *= WHTEFFICACY;
309			scalecolor(scan[i], mult);
310	greg	3.4	}
311			}
312
313
314			putmapping(fp) /* put out mapping function */
315			FILE *fp;
316			{
317			double b, s;
318			register int i;
319	greg	3.7	double wlum, sf, dlum;
320	greg	3.4
321			sf = scalef*inpexp;
322			if (lumf == cielum) sf *= WHTEFFICACY;
323			s = (bwmax - bwmin)/HISTRES;
324			for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) {
325			wlum = Lb(b);
326	greg	3.7	if (what2do&DO_LINEAR) {
327			dlum = sf*wlum;
328			if (dlum > ldmax) dlum = ldmax;
329			else if (dlum < ldmin) dlum = ldmin;
330			fprintf(fp, "%e %e\n", wlum, dlum);
331			} else
332	greg	3.4	fprintf(fp, "%e %e\n", wlum, Lb(BLw(wlum)));
333	greg	3.1	}
334			}