| 11 |
|
#include "pcond.h" |
| 12 |
|
|
| 13 |
|
|
| 14 |
< |
#define CVRATIO 0.025 /* fraction of pixels allowed > env. */ |
| 14 |
> |
#define CVRATIO 0.025 /* fraction of samples allowed > env. */ |
| 15 |
|
|
| 16 |
|
#define exp10(x) exp(2.302585093*(x)) |
| 17 |
|
|
| 18 |
< |
int modhist[HISTRES]; /* modified histogram */ |
| 18 |
> |
float modhist[HISTRES]; /* modified histogram */ |
| 19 |
> |
double mhistot; /* modified histogram total */ |
| 20 |
|
float cumf[HISTRES+1]; /* cumulative distribution function */ |
| 21 |
|
|
| 22 |
|
|
| 23 |
|
mkcumf() /* make cumulative distribution function */ |
| 24 |
|
{ |
| 25 |
|
register int i; |
| 26 |
< |
register long sum; |
| 26 |
> |
register double sum; |
| 27 |
|
|
| 28 |
< |
cumf[0] = 0.; |
| 29 |
< |
sum = modhist[0]; |
| 30 |
< |
for (i = 1; i < HISTRES; i++) { |
| 31 |
< |
cumf[i] = (double)sum/histot; |
| 28 |
> |
mhistot = 0.; /* compute modified total */ |
| 29 |
> |
for (i = 0; i < HISTRES; i++) |
| 30 |
> |
mhistot += modhist[i]; |
| 31 |
> |
|
| 32 |
> |
sum = 0.; /* compute cumulative function */ |
| 33 |
> |
for (i = 0; i < HISTRES; i++) { |
| 34 |
> |
cumf[i] = sum/mhistot; |
| 35 |
|
sum += modhist[i]; |
| 36 |
|
} |
| 37 |
|
cumf[HISTRES] = 1.; |
| 112 |
|
int |
| 113 |
|
mkbrmap() /* make dynamic range map */ |
| 114 |
|
{ |
| 111 |
– |
int hdiffs[HISTRES], above, below; |
| 115 |
|
double T, b, s; |
| 116 |
< |
int maxd, maxi, sd; |
| 116 |
> |
double ceiling, trimmings; |
| 117 |
|
register int i; |
| 118 |
|
/* copy initial histogram */ |
| 119 |
< |
for (i = 0; i < HISTRES; i++) |
| 117 |
< |
modhist[i] = bwhist[i]; |
| 118 |
< |
T = histot * (bwmax - bwmin) / HISTRES; |
| 119 |
> |
bcopy((char *)bwhist, (char *)modhist, sizeof(modhist)); |
| 120 |
|
s = (bwmax - bwmin)/HISTRES; |
| 121 |
|
/* loop until satisfactory */ |
| 122 |
< |
for ( ; ; ) { |
| 123 |
< |
mkcumf(); /* sync brightness mapping */ |
| 124 |
< |
above = below = 0; /* compute visibility overflow */ |
| 122 |
> |
do { |
| 123 |
> |
mkcumf(); /* sync brightness mapping */ |
| 124 |
> |
if (mhistot <= histot*CVRATIO) |
| 125 |
> |
return(-1); /* no compression needed! */ |
| 126 |
> |
T = mhistot * (bwmax - bwmin) / HISTRES; |
| 127 |
> |
trimmings = 0.; /* clip to envelope */ |
| 128 |
|
for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) { |
| 129 |
< |
hdiffs[i] = modhist[i] - (int)(T*clampf(Lb(b)) + .5); |
| 130 |
< |
if (hdiffs[i] > 0) above += hdiffs[i]; |
| 131 |
< |
else below -= hdiffs[i]; |
| 129 |
> |
ceiling = T*clampf(Lb(b)); |
| 130 |
> |
if (modhist[i] > ceiling) { |
| 131 |
> |
trimmings += modhist[i] - ceiling; |
| 132 |
> |
modhist[i] = ceiling; |
| 133 |
> |
} |
| 134 |
|
} |
| 135 |
< |
if (above <= histot*CVRATIO) |
| 136 |
< |
break; /* close enough */ |
| 137 |
< |
if (above-below >= 0) |
| 132 |
< |
return(-1); /* Houston, we have a problem.... */ |
| 133 |
< |
/* original looped here as well (BEGIN_L2) */ |
| 134 |
< |
maxd = 0; /* find largest overvis */ |
| 135 |
< |
for (i = 0; i < HISTRES; i++) |
| 136 |
< |
if (hdiffs[i] > maxd) |
| 137 |
< |
maxd = hdiffs[maxi=i]; |
| 138 |
< |
/* broke loop here when (maxd == 0) (BREAK_L2) */ |
| 139 |
< |
for (sd = shiftdir((maxi+.5)/HISTRES*(bwmax-bwmin)+bwmin); |
| 140 |
< |
hdiffs[maxi] == maxd; sd = -sd) |
| 141 |
< |
for (i = maxi+sd; i >= 0 & i < HISTRES; i += sd) |
| 142 |
< |
if (hdiffs[i] < 0) { |
| 143 |
< |
if (hdiffs[i] <= -maxd) { |
| 144 |
< |
modhist[i] += maxd; |
| 145 |
< |
modhist[maxi] -= maxd; |
| 146 |
< |
hdiffs[i] += maxd; |
| 147 |
< |
hdiffs[maxi] = 0; |
| 148 |
< |
} else { |
| 149 |
< |
modhist[maxi] += hdiffs[i]; |
| 150 |
< |
modhist[i] -= hdiffs[i]; |
| 151 |
< |
hdiffs[maxi] += hdiffs[i]; |
| 152 |
< |
hdiffs[i] = 0; |
| 153 |
< |
} |
| 154 |
< |
break; |
| 155 |
< |
} |
| 156 |
< |
/* (END_L2) */ |
| 157 |
< |
} |
| 158 |
< |
return(0); |
| 135 |
> |
} while (trimmings > histot*CVRATIO); |
| 136 |
> |
|
| 137 |
> |
return(0); /* we got it */ |
| 138 |
|
} |
| 139 |
|
|
| 140 |
|
|
| 208 |
|
fprintf(fp, "%e %e\n", wlum, Lb(BLw(wlum))); |
| 209 |
|
} |
| 210 |
|
} |
| 232 |
– |
|
| 233 |
– |
|
| 234 |
– |
#ifdef DEBUG |
| 235 |
– |
doplots() /* generate debugging plots */ |
| 236 |
– |
{ |
| 237 |
– |
double T, b, s; |
| 238 |
– |
FILE *fp; |
| 239 |
– |
char fname[128]; |
| 240 |
– |
register int i; |
| 241 |
– |
|
| 242 |
– |
T = histot * (bwmax - bwmin) / HISTRES; |
| 243 |
– |
s = (bwmax - bwmin)/HISTRES; |
| 244 |
– |
|
| 245 |
– |
sprintf(fname, "%s_hist.plt", infn); |
| 246 |
– |
if ((fp = fopen(fname, "w")) == NULL) |
| 247 |
– |
syserror(fname); |
| 248 |
– |
fputs("include=curve.plt\n", fp); |
| 249 |
– |
fputs("title=\"Brightness Frequency Distribution\"\n", fp); |
| 250 |
– |
fprintf(fp, "subtitle=%s\n", infn); |
| 251 |
– |
fputs("ymin=0\n", fp); |
| 252 |
– |
fputs("xlabel=\"Perceptual Brightness B(Lw)\"\n", fp); |
| 253 |
– |
fputs("ylabel=\"Frequency Count\"\n", fp); |
| 254 |
– |
fputs("Alabel=\"Histogram\"\n", fp); |
| 255 |
– |
fputs("Alintype=0\n", fp); |
| 256 |
– |
fputs("Blabel=\"Envelope\"\n", fp); |
| 257 |
– |
fputs("Bsymsize=0\n", fp); |
| 258 |
– |
fputs("Adata=\n", fp); |
| 259 |
– |
for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) |
| 260 |
– |
fprintf(fp, "\t%f %d\n", b, modhist[i]); |
| 261 |
– |
fputs(";\nBdata=\n", fp); |
| 262 |
– |
for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) |
| 263 |
– |
fprintf(fp, "\t%f %f\n", b, T*clampf(Lb(b))); |
| 264 |
– |
fputs(";\n", fp); |
| 265 |
– |
fclose(fp); |
| 266 |
– |
} |
| 267 |
– |
#endif |
