1 |
greg |
3.1 |
#ifndef lint |
2 |
greg |
3.11 |
static const char RCSid[] = "$Id$"; |
3 |
greg |
3.1 |
#endif |
4 |
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/* |
5 |
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* Routines for computing and applying brightness mapping. |
6 |
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*/ |
7 |
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8 |
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#include "pcond.h" |
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10 |
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11 |
greg |
3.5 |
#define CVRATIO 0.025 /* fraction of samples allowed > env. */ |
12 |
greg |
3.1 |
|
13 |
gwlarson |
3.10 |
#define LN_10 2.30258509299404568402 |
14 |
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#define exp10(x) exp(LN_10*(x)) |
15 |
greg |
3.1 |
|
16 |
greg |
3.11 |
double modhist[HISTRES]; /* modified histogram */ |
17 |
greg |
3.5 |
double mhistot; /* modified histogram total */ |
18 |
greg |
3.11 |
double cumf[HISTRES+1]; /* cumulative distribution function */ |
19 |
greg |
3.1 |
|
20 |
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21 |
greg |
3.8 |
getfixations(fp) /* load fixation history list */ |
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FILE *fp; |
23 |
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{ |
24 |
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#define FIXHUNK 128 |
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RESOLU fvres; |
26 |
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int pos[2]; |
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register int px, py, i; |
28 |
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/* initialize our resolution struct */ |
29 |
greg |
3.11 |
if ((fvres.rt=inpres.rt)&YMAJOR) { |
30 |
greg |
3.8 |
fvres.xr = fvxr; |
31 |
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fvres.yr = fvyr; |
32 |
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} else { |
33 |
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fvres.xr = fvyr; |
34 |
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fvres.yr = fvxr; |
35 |
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} |
36 |
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/* read each picture position */ |
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while (fscanf(fp, "%d %d", &pos[0], &pos[1]) == 2) { |
38 |
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/* convert to closest index in foveal image */ |
39 |
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loc2pix(pos, &fvres, |
40 |
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(pos[0]+.5)/inpres.xr, (pos[1]+.5)/inpres.yr); |
41 |
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/* include nine neighborhood samples */ |
42 |
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for (px = pos[0]-1; px <= pos[0]+1; px++) { |
43 |
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if (px < 0 || px >= fvxr) |
44 |
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continue; |
45 |
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for (py = pos[1]-1; py <= pos[1]+1; py++) { |
46 |
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if (py < 0 || py >= fvyr) |
47 |
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continue; |
48 |
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for (i = nfixations; i-- > 0; ) |
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if (fixlst[i][0] == px && |
50 |
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fixlst[i][1] == py) |
51 |
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break; |
52 |
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if (i >= 0) |
53 |
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continue; /* already there */ |
54 |
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if (nfixations % FIXHUNK == 0) { |
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if (nfixations) |
56 |
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fixlst = (short (*)[2]) |
57 |
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realloc((char *)fixlst, |
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(nfixations+FIXHUNK)* |
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2*sizeof(short)); |
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else |
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fixlst = (short (*)[2])malloc( |
62 |
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FIXHUNK*2*sizeof(short) |
63 |
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); |
64 |
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if (fixlst == NULL) |
65 |
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syserror("malloc"); |
66 |
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} |
67 |
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fixlst[nfixations][0] = px; |
68 |
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fixlst[nfixations][1] = py; |
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nfixations++; |
70 |
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} |
71 |
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} |
72 |
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} |
73 |
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if (!feof(fp)) { |
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fprintf(stderr, "%s: format error reading fixation data\n", |
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progname); |
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exit(1); |
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} |
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#undef FIXHUNK |
79 |
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} |
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81 |
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82 |
gwlarson |
3.10 |
gethisto(fp) /* load precomputed luminance histogram */ |
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FILE *fp; |
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{ |
85 |
greg |
3.11 |
double histo[MAXPREHIST]; |
86 |
gwlarson |
3.10 |
double histart, histep; |
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double l, b, lastb, w; |
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int n; |
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register int i; |
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/* load data */ |
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for (i = 0; i < MAXPREHIST && |
92 |
greg |
3.11 |
fscanf(fp, "%lf %lf", &b, &histo[i]) == 2; i++) { |
93 |
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if (i > 1 && fabs(b - lastb - histep) > .001) { |
94 |
gwlarson |
3.10 |
fprintf(stderr, |
95 |
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"%s: uneven step size in histogram data\n", |
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progname); |
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exit(1); |
98 |
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} |
99 |
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if (i == 1) |
100 |
greg |
3.11 |
if ((histep = b - (histart = lastb)) <= FTINY) { |
101 |
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fprintf(stderr, |
102 |
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"%s: illegal step in histogram data\n", |
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progname); |
104 |
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exit(1); |
105 |
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} |
106 |
gwlarson |
3.10 |
lastb = b; |
107 |
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} |
108 |
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if (i < 2 || !feof(fp)) { |
109 |
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fprintf(stderr, |
110 |
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"%s: format/length error loading histogram (log10L %f at %d)\n", |
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progname, b, i); |
112 |
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exit(1); |
113 |
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} |
114 |
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n = i; |
115 |
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histart *= LN_10; |
116 |
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histep *= LN_10; |
117 |
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/* find extrema */ |
118 |
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for (i = 0; i < n && histo[i] <= FTINY; i++) |
119 |
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; |
120 |
greg |
3.11 |
bwmin = histart + (i-.001)*histep; |
121 |
gwlarson |
3.10 |
for (i = n; i-- && histo[i] <= FTINY; ) |
122 |
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; |
123 |
greg |
3.11 |
bwmax = histart + (i+1.001)*histep; |
124 |
gwlarson |
3.10 |
if (bwmax > Bl(LMAX)) |
125 |
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bwmax = Bl(LMAX); |
126 |
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if (bwmin < Bl(LMIN)) |
127 |
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bwmin = Bl(LMIN); |
128 |
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else /* duplicate bottom bin */ |
129 |
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bwmin = bwmax - (bwmax-bwmin)*HISTRES/(HISTRES-1); |
130 |
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/* convert histogram */ |
131 |
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bwavg = 0.; histot = 0.; |
132 |
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for (i = 0; i < HISTRES; i++) |
133 |
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bwhist[i] = 0.; |
134 |
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for (i = 0, b = histart; i < n; i++, b += histep) { |
135 |
greg |
3.11 |
if (b < bwmin+FTINY) continue; |
136 |
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if (b >= bwmax-FTINY) break; |
137 |
gwlarson |
3.10 |
w = histo[i]; |
138 |
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bwavg += w*b; |
139 |
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bwhist[bwhi(b)] += w; |
140 |
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histot += w; |
141 |
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} |
142 |
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bwavg /= histot; |
143 |
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if (bwmin > Bl(LMIN)+FTINY) { /* add false samples at bottom */ |
144 |
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bwhist[1] *= 0.5; |
145 |
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bwhist[0] += bwhist[1]; |
146 |
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} |
147 |
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} |
148 |
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149 |
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150 |
greg |
3.8 |
double |
151 |
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centprob(x, y) /* center-weighting probability function */ |
152 |
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int x, y; |
153 |
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{ |
154 |
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double xr, yr, p; |
155 |
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/* paraboloid, 0 at 90 degrees from center */ |
156 |
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xr = (x - .5*(fvxr-1))/90.; /* 180 degree fisheye has fv?r == 90 */ |
157 |
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yr = (y - .5*(fvyr-1))/90.; |
158 |
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p = 1. - xr*xr - yr*yr; |
159 |
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return(p < 0. ? 0. : p); |
160 |
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} |
161 |
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162 |
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163 |
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comphist() /* create foveal sampling histogram */ |
164 |
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{ |
165 |
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double l, b, w, lwmin, lwmax; |
166 |
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register int x, y; |
167 |
gwlarson |
3.10 |
/* check for precalculated histogram */ |
168 |
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if (what2do&DO_PREHIST) |
169 |
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return; |
170 |
greg |
3.8 |
lwmin = 1e10; /* find extrema */ |
171 |
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lwmax = 0.; |
172 |
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for (y = 0; y < fvyr; y++) |
173 |
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for (x = 0; x < fvxr; x++) { |
174 |
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l = plum(fovscan(y)[x]); |
175 |
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if (l < lwmin) lwmin = l; |
176 |
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if (l > lwmax) lwmax = l; |
177 |
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} |
178 |
greg |
3.9 |
lwmax *= 1.01; |
179 |
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if (lwmax > LMAX) |
180 |
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lwmax = LMAX; |
181 |
greg |
3.8 |
bwmax = Bl(lwmax); |
182 |
greg |
3.9 |
if (lwmin < LMIN) { |
183 |
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lwmin = LMIN; |
184 |
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bwmin = Bl(LMIN); |
185 |
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} else { /* duplicate bottom bin */ |
186 |
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bwmin = bwmax - (bwmax-Bl(lwmin))*HISTRES/(HISTRES-1); |
187 |
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lwmin = Lb(bwmin); |
188 |
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} |
189 |
greg |
3.8 |
/* (re)compute histogram */ |
190 |
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bwavg = 0.; |
191 |
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histot = 0.; |
192 |
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for (x = 0; x < HISTRES; x++) |
193 |
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bwhist[x] = 0.; |
194 |
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/* global average */ |
195 |
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if (!(what2do&DO_FIXHIST) || fixfrac < 1.-FTINY) |
196 |
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for (y = 0; y < fvyr; y++) |
197 |
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for (x = 0; x < fvxr; x++) { |
198 |
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l = plum(fovscan(y)[x]); |
199 |
greg |
3.11 |
if (l < lwmin+FTINY) continue; |
200 |
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if (l >= lwmax-FTINY) continue; |
201 |
greg |
3.8 |
b = Bl(l); |
202 |
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w = what2do&DO_CWEIGHT ? centprob(x,y) : 1.; |
203 |
gwlarson |
3.10 |
bwavg += w*b; |
204 |
greg |
3.8 |
bwhist[bwhi(b)] += w; |
205 |
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histot += w; |
206 |
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} |
207 |
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/* average fixation points */ |
208 |
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if (what2do&DO_FIXHIST && nfixations > 0) { |
209 |
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if (histot > FTINY) |
210 |
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w = fixfrac/(1.-fixfrac)*histot/nfixations; |
211 |
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else |
212 |
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w = 1.; |
213 |
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for (x = 0; x < nfixations; x++) { |
214 |
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l = plum(fovscan(fixlst[x][1])[fixlst[x][0]]); |
215 |
greg |
3.11 |
if (l < lwmin+FTINY) continue; |
216 |
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if (l >= lwmax-FTINY) continue; |
217 |
greg |
3.8 |
b = Bl(l); |
218 |
gwlarson |
3.10 |
bwavg += w*b; |
219 |
greg |
3.8 |
bwhist[bwhi(b)] += w; |
220 |
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histot += w; |
221 |
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} |
222 |
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} |
223 |
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bwavg /= histot; |
224 |
greg |
3.9 |
if (lwmin > LMIN+FTINY) { /* add false samples at bottom */ |
225 |
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bwhist[1] *= 0.5; |
226 |
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bwhist[0] += bwhist[1]; |
227 |
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} |
228 |
greg |
3.8 |
} |
229 |
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230 |
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231 |
greg |
3.1 |
mkcumf() /* make cumulative distribution function */ |
232 |
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{ |
233 |
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register int i; |
234 |
greg |
3.5 |
register double sum; |
235 |
greg |
3.1 |
|
236 |
greg |
3.5 |
mhistot = 0.; /* compute modified total */ |
237 |
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for (i = 0; i < HISTRES; i++) |
238 |
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mhistot += modhist[i]; |
239 |
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240 |
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sum = 0.; /* compute cumulative function */ |
241 |
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for (i = 0; i < HISTRES; i++) { |
242 |
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cumf[i] = sum/mhistot; |
243 |
greg |
3.1 |
sum += modhist[i]; |
244 |
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} |
245 |
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cumf[HISTRES] = 1.; |
246 |
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} |
247 |
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248 |
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249 |
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double |
250 |
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cf(b) /* return cumulative function at b */ |
251 |
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double b; |
252 |
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{ |
253 |
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double x; |
254 |
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register int i; |
255 |
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256 |
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i = x = HISTRES*(b - bwmin)/(bwmax - bwmin); |
257 |
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x -= (double)i; |
258 |
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return(cumf[i]*(1.-x) + cumf[i+1]*x); |
259 |
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} |
260 |
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261 |
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262 |
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double |
263 |
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BLw(Lw) /* map world luminance to display brightness */ |
264 |
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double Lw; |
265 |
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{ |
266 |
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double b; |
267 |
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268 |
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if (Lw <= LMIN || (b = Bl(Lw)) <= bwmin+FTINY) |
269 |
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return(Bldmin); |
270 |
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if (b >= bwmax-FTINY) |
271 |
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return(Bldmax); |
272 |
greg |
3.4 |
return(Bldmin + cf(b)*(Bldmax-Bldmin)); |
273 |
greg |
3.1 |
} |
274 |
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275 |
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276 |
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double |
277 |
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htcontrs(La) /* human threshold contrast sensitivity, dL(La) */ |
278 |
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double La; |
279 |
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{ |
280 |
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double l10La, l10dL; |
281 |
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/* formula taken from Ferwerda et al. [SG96] */ |
282 |
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if (La < 1.148e-4) |
283 |
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return(1.38e-3); |
284 |
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l10La = log10(La); |
285 |
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if (l10La < -1.44) /* rod response regime */ |
286 |
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l10dL = pow(.405*l10La + 1.6, 2.18) - 2.86; |
287 |
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else if (l10La < -.0184) |
288 |
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l10dL = l10La - .395; |
289 |
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else if (l10La < 1.9) /* cone response regime */ |
290 |
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l10dL = pow(.249*l10La + .65, 2.7) - .72; |
291 |
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else |
292 |
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l10dL = l10La - 1.255; |
293 |
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294 |
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return(exp10(l10dL)); |
295 |
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} |
296 |
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297 |
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298 |
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double |
299 |
greg |
3.11 |
clampf(Lw) /* histogram clamping function */ |
300 |
greg |
3.1 |
double Lw; |
301 |
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{ |
302 |
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double bLw, ratio; |
303 |
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304 |
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bLw = BLw(Lw); /* apply current brightness map */ |
305 |
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ratio = what2do&DO_HSENS ? htcontrs(Lb(bLw))/htcontrs(Lw) : Lb(bLw)/Lw; |
306 |
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return(ratio/(Lb1(bLw)*(Bldmax-Bldmin)*Bl1(Lw))); |
307 |
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} |
308 |
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|
309 |
greg |
3.11 |
double |
310 |
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crfactor(Lw) /* contrast reduction factor */ |
311 |
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double Lw; |
312 |
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{ |
313 |
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int i = HISTRES*(Bl(Lw) - bwmin)/(bwmax - bwmin); |
314 |
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double bLw, ratio, Tdb; |
315 |
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316 |
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if (i <= 0) |
317 |
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return(1.0); |
318 |
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if (i >= HISTRES) |
319 |
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return(1.0); |
320 |
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bLw = BLw(Lw); |
321 |
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ratio = what2do&DO_HSENS ? htcontrs(Lb(bLw))/htcontrs(Lw) : Lb(bLw)/Lw; |
322 |
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Tdb = mhistot * (bwmax - bwmin) / HISTRES; |
323 |
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return(modhist[i]*Lb1(bLw)*(Bldmax-Bldmin)*Bl1(Lw)/(Tdb*ratio)); |
324 |
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} |
325 |
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326 |
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327 |
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#if ADJ_VEIL |
328 |
|
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mkcrfimage() /* compute contrast reduction factor image */ |
329 |
|
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{ |
330 |
|
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int i; |
331 |
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float *crfptr; |
332 |
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COLOR *fovptr; |
333 |
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334 |
|
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if (crfimg == NULL) |
335 |
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crfimg = (float *)malloc(fvxr*fvyr*sizeof(float)); |
336 |
|
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if (crfimg == NULL) |
337 |
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syserror("malloc"); |
338 |
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crfptr = crfimg; |
339 |
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fovptr = fovimg; |
340 |
|
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for (i = fvxr*fvyr; i--; crfptr++, fovptr++) |
341 |
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crfptr[0] = crfactor(plum(fovptr[0])); |
342 |
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} |
343 |
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#endif |
344 |
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|
345 |
greg |
3.1 |
|
346 |
|
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int |
347 |
|
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mkbrmap() /* make dynamic range map */ |
348 |
|
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{ |
349 |
greg |
3.11 |
double Tdb, b, s; |
350 |
greg |
3.5 |
double ceiling, trimmings; |
351 |
greg |
3.1 |
register int i; |
352 |
|
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/* copy initial histogram */ |
353 |
greg |
3.5 |
bcopy((char *)bwhist, (char *)modhist, sizeof(modhist)); |
354 |
greg |
3.11 |
s = (bwmax - bwmin)/HISTRES; /* s is delta b */ |
355 |
greg |
3.1 |
/* loop until satisfactory */ |
356 |
greg |
3.5 |
do { |
357 |
|
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mkcumf(); /* sync brightness mapping */ |
358 |
|
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if (mhistot <= histot*CVRATIO) |
359 |
|
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return(-1); /* no compression needed! */ |
360 |
greg |
3.11 |
Tdb = mhistot * s; |
361 |
greg |
3.5 |
trimmings = 0.; /* clip to envelope */ |
362 |
greg |
3.1 |
for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) { |
363 |
greg |
3.11 |
ceiling = Tdb*clampf(Lb(b)); |
364 |
greg |
3.5 |
if (modhist[i] > ceiling) { |
365 |
|
|
trimmings += modhist[i] - ceiling; |
366 |
|
|
modhist[i] = ceiling; |
367 |
|
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} |
368 |
greg |
3.1 |
} |
369 |
greg |
3.5 |
} while (trimmings > histot*CVRATIO); |
370 |
|
|
|
371 |
greg |
3.11 |
#if ADJ_VEIL |
372 |
|
|
mkcrfimage(); /* contrast reduction image */ |
373 |
|
|
#endif |
374 |
|
|
|
375 |
greg |
3.5 |
return(0); /* we got it */ |
376 |
greg |
3.1 |
} |
377 |
|
|
|
378 |
|
|
|
379 |
|
|
scotscan(scan, xres) /* apply scotopic color sensitivity loss */ |
380 |
|
|
COLOR *scan; |
381 |
|
|
int xres; |
382 |
|
|
{ |
383 |
|
|
COLOR ctmp; |
384 |
|
|
double incolor, b, Lw; |
385 |
|
|
register int i; |
386 |
|
|
|
387 |
|
|
for (i = 0; i < xres; i++) { |
388 |
|
|
Lw = plum(scan[i]); |
389 |
|
|
if (Lw >= TopMesopic) |
390 |
|
|
incolor = 1.; |
391 |
|
|
else if (Lw <= BotMesopic) |
392 |
|
|
incolor = 0.; |
393 |
|
|
else |
394 |
|
|
incolor = (Lw - BotMesopic) / |
395 |
|
|
(TopMesopic - BotMesopic); |
396 |
|
|
if (incolor < 1.-FTINY) { |
397 |
greg |
3.2 |
b = (1.-incolor)*slum(scan[i])*inpexp/SWNORM; |
398 |
|
|
if (lumf == rgblum) b /= WHTEFFICACY; |
399 |
|
|
setcolor(ctmp, b, b, b); |
400 |
greg |
3.1 |
if (incolor <= FTINY) |
401 |
|
|
setcolor(scan[i], 0., 0., 0.); |
402 |
|
|
else |
403 |
|
|
scalecolor(scan[i], incolor); |
404 |
|
|
addcolor(scan[i], ctmp); |
405 |
|
|
} |
406 |
|
|
} |
407 |
|
|
} |
408 |
|
|
|
409 |
|
|
|
410 |
|
|
mapscan(scan, xres) /* apply tone mapping operator to scanline */ |
411 |
|
|
COLOR *scan; |
412 |
|
|
int xres; |
413 |
|
|
{ |
414 |
|
|
double mult, Lw, b; |
415 |
greg |
3.11 |
register int x; |
416 |
greg |
3.1 |
|
417 |
greg |
3.11 |
for (x = 0; x < xres; x++) { |
418 |
|
|
Lw = plum(scan[x]); |
419 |
greg |
3.1 |
if (Lw < LMIN) { |
420 |
greg |
3.11 |
setcolor(scan[x], 0., 0., 0.); |
421 |
greg |
3.1 |
continue; |
422 |
|
|
} |
423 |
greg |
3.11 |
b = BLw(Lw); /* apply brightness mapping */ |
424 |
|
|
mult = (Lb(b) - ldmin)/(ldmax - ldmin)/(Lw*inpexp); |
425 |
greg |
3.1 |
if (lumf == rgblum) mult *= WHTEFFICACY; |
426 |
greg |
3.11 |
scalecolor(scan[x], mult); |
427 |
greg |
3.4 |
} |
428 |
|
|
} |
429 |
|
|
|
430 |
|
|
|
431 |
|
|
putmapping(fp) /* put out mapping function */ |
432 |
|
|
FILE *fp; |
433 |
|
|
{ |
434 |
|
|
double b, s; |
435 |
|
|
register int i; |
436 |
greg |
3.7 |
double wlum, sf, dlum; |
437 |
greg |
3.4 |
|
438 |
|
|
sf = scalef*inpexp; |
439 |
|
|
if (lumf == cielum) sf *= WHTEFFICACY; |
440 |
|
|
s = (bwmax - bwmin)/HISTRES; |
441 |
|
|
for (i = 0, b = bwmin + .5*s; i < HISTRES; i++, b += s) { |
442 |
|
|
wlum = Lb(b); |
443 |
greg |
3.7 |
if (what2do&DO_LINEAR) { |
444 |
|
|
dlum = sf*wlum; |
445 |
|
|
if (dlum > ldmax) dlum = ldmax; |
446 |
|
|
else if (dlum < ldmin) dlum = ldmin; |
447 |
|
|
fprintf(fp, "%e %e\n", wlum, dlum); |
448 |
|
|
} else |
449 |
greg |
3.4 |
fprintf(fp, "%e %e\n", wlum, Lb(BLw(wlum))); |
450 |
greg |
3.1 |
} |
451 |
|
|
} |