| 1 | greg | 3.1 | /* Copyright (c) 1996 Regents of the University of California */ | 
| 2 |  |  |  | 
| 3 |  |  | #ifndef lint | 
| 4 |  |  | static char SCCSid[] = "$SunId$ LBL"; | 
| 5 |  |  | #endif | 
| 6 |  |  |  | 
| 7 |  |  | /* | 
| 8 |  |  | * Routines for veiling glare and loss of acuity. | 
| 9 |  |  | */ | 
| 10 |  |  |  | 
| 11 |  |  | #include "pcond.h" | 
| 12 |  |  |  | 
| 13 | greg | 3.3 | /************** VEILING STUFF *****************/ | 
| 14 | greg | 3.1 |  | 
| 15 |  |  | #define VADAPT          0.08            /* fraction of adaptation from veil */ | 
| 16 |  |  |  | 
| 17 |  |  | extern COLOR    *fovimg;                /* foveal (1 degree) averaged image */ | 
| 18 |  |  | extern short    fvxr, fvyr;             /* foveal image resolution */ | 
| 19 |  |  |  | 
| 20 |  |  | #define fovscan(y)      (fovimg+(y)*fvxr) | 
| 21 |  |  |  | 
| 22 |  |  | static COLOR    *veilimg;               /* veiling image */ | 
| 23 |  |  |  | 
| 24 |  |  | #define veilscan(y)     (veilimg+(y)*fvxr) | 
| 25 |  |  |  | 
| 26 | greg | 3.2 | static float    (*raydir)[3] = NULL;    /* ray direction for each pixel */ | 
| 27 | greg | 3.1 |  | 
| 28 |  |  | #define rdirscan(y)     (raydir+(y)*fvxr) | 
| 29 |  |  |  | 
| 30 |  |  |  | 
| 31 |  |  | compraydir()                            /* compute ray directions */ | 
| 32 |  |  | { | 
| 33 | greg | 3.2 | FVECT   rorg, rdir; | 
| 34 | greg | 3.1 | double  h, v; | 
| 35 |  |  | register int    x, y; | 
| 36 |  |  |  | 
| 37 |  |  | if (raydir != NULL)             /* already done? */ | 
| 38 |  |  | return; | 
| 39 | greg | 3.2 | raydir = (float (*)[3])malloc(fvxr*fvyr*3*sizeof(float)); | 
| 40 | greg | 3.1 | if (raydir == NULL) | 
| 41 |  |  | syserror("malloc"); | 
| 42 |  |  |  | 
| 43 |  |  | for (y = 0; y < fvyr; y++) { | 
| 44 |  |  | switch (inpres.or) { | 
| 45 |  |  | case YMAJOR: case YMAJOR|XDECR: | 
| 46 |  |  | v = (y+.5)/fvyr; break; | 
| 47 |  |  | case YMAJOR|YDECR: case YMAJOR|YDECR|XDECR: | 
| 48 |  |  | v = 1. - (y+.5)/fvyr; break; | 
| 49 |  |  | case 0: case YDECR: | 
| 50 |  |  | h = (y+.5)/fvyr; break; | 
| 51 |  |  | case XDECR: case XDECR|YDECR: | 
| 52 |  |  | h = 1. - (y+.5)/fvyr; break; | 
| 53 |  |  | } | 
| 54 |  |  | for (x = 0; x < fvxr; x++) { | 
| 55 |  |  | switch (inpres.or) { | 
| 56 |  |  | case YMAJOR: case YMAJOR|YDECR: | 
| 57 |  |  | h = (x+.5)/fvxr; break; | 
| 58 |  |  | case YMAJOR|XDECR: case YMAJOR|XDECR|YDECR: | 
| 59 |  |  | h = 1. - (x+.5)/fvxr; break; | 
| 60 |  |  | case 0: case XDECR: | 
| 61 |  |  | v = (x+.5)/fvxr; break; | 
| 62 |  |  | case YDECR: case YDECR|XDECR: | 
| 63 |  |  | v = 1. - (x+.5)/fvxr; break; | 
| 64 |  |  | } | 
| 65 | greg | 3.2 | if (viewray(rorg, rdir, &ourview, h, v) | 
| 66 |  |  | >= -FTINY) { | 
| 67 |  |  | rdirscan(y)[x][0] = rdir[0]; | 
| 68 |  |  | rdirscan(y)[x][1] = rdir[1]; | 
| 69 |  |  | rdirscan(y)[x][2] = rdir[2]; | 
| 70 |  |  | } else { | 
| 71 | greg | 3.1 | rdirscan(y)[x][0] = | 
| 72 |  |  | rdirscan(y)[x][1] = | 
| 73 |  |  | rdirscan(y)[x][2] = 0.0; | 
| 74 |  |  | } | 
| 75 |  |  | } | 
| 76 |  |  | } | 
| 77 |  |  | } | 
| 78 |  |  |  | 
| 79 |  |  |  | 
| 80 |  |  | compveil()                              /* compute veiling image */ | 
| 81 |  |  | { | 
| 82 |  |  | double  t2, t2sum; | 
| 83 |  |  | COLOR   ctmp, vsum; | 
| 84 |  |  | int     px, py; | 
| 85 |  |  | register int    x, y; | 
| 86 |  |  | /* compute ray directions */ | 
| 87 |  |  | compraydir(); | 
| 88 |  |  | /* compute veil image */ | 
| 89 |  |  | veilimg = (COLOR *)malloc(fvxr*fvyr*sizeof(COLOR)); | 
| 90 |  |  | if (veilimg == NULL) | 
| 91 |  |  | syserror("malloc"); | 
| 92 |  |  | for (py = 0; py < fvyr; py++) | 
| 93 |  |  | for (px = 0; px < fvxr; px++) { | 
| 94 |  |  | t2sum = 0.; | 
| 95 |  |  | setcolor(vsum, 0., 0., 0.); | 
| 96 |  |  | for (y = 0; y < fvyr; y++) | 
| 97 |  |  | for (x = 0; x < fvxr; x++) { | 
| 98 |  |  | if (x == px && y == py) continue; | 
| 99 |  |  | t2 = DOT(rdirscan(py)[px], | 
| 100 |  |  | rdirscan(y)[x]); | 
| 101 |  |  | if (t2 <= FTINY) continue; | 
| 102 |  |  | t2 = acos(t2); | 
| 103 |  |  | t2 = 1./(t2*t2); | 
| 104 |  |  | copycolor(ctmp, fovscan(y)[x]); | 
| 105 |  |  | scalecolor(ctmp, t2); | 
| 106 |  |  | addcolor(vsum, ctmp); | 
| 107 |  |  | t2sum += t2; | 
| 108 |  |  | } | 
| 109 |  |  | /* VADAPT of original is subtracted in addveil() */ | 
| 110 |  |  | scalecolor(vsum, VADAPT/t2sum); | 
| 111 |  |  | copycolor(veilscan(py)[px], vsum); | 
| 112 |  |  | } | 
| 113 |  |  | } | 
| 114 |  |  |  | 
| 115 |  |  |  | 
| 116 |  |  | addveil(sl, y)                          /* add veil to scanline */ | 
| 117 |  |  | COLOR   *sl; | 
| 118 |  |  | int     y; | 
| 119 |  |  | { | 
| 120 |  |  | int     vx, vy; | 
| 121 |  |  | double  dx, dy; | 
| 122 |  |  | double  lv, uv; | 
| 123 |  |  | register int    x, i; | 
| 124 |  |  |  | 
| 125 |  |  | vy = dy = (y+.5)/numscans(&inpres)*fvyr - .5; | 
| 126 |  |  | if (vy >= fvyr-1) vy--; | 
| 127 |  |  | dy -= (double)vy; | 
| 128 |  |  | for (x = 0; x < scanlen(&inpres); x++) { | 
| 129 |  |  | vx = dx = (x+.5)/scanlen(&inpres)*fvxr - .5; | 
| 130 |  |  | if (vx >= fvxr-1) vx--; | 
| 131 |  |  | dx -= (double)vx; | 
| 132 |  |  | for (i = 0; i < 3; i++) { | 
| 133 |  |  | lv = (1.-dy)*colval(veilscan(vy)[vx],i) + | 
| 134 |  |  | dy*colval(veilscan(vy+1)[vx],i); | 
| 135 |  |  | uv = (1.-dy)*colval(veilscan(vy)[vx+1],i) + | 
| 136 |  |  | dy*colval(veilscan(vy+1)[vx+1],i); | 
| 137 |  |  | colval(sl[x],i) = (1.-VADAPT)*colval(sl[x],i) + | 
| 138 |  |  | (1.-dx)*lv + dx*uv; | 
| 139 |  |  | } | 
| 140 |  |  | } | 
| 141 | greg | 3.3 | } | 
| 142 |  |  |  | 
| 143 |  |  |  | 
| 144 |  |  | /****************** ACUITY STUFF *******************/ | 
| 145 |  |  |  | 
| 146 |  |  | typedef struct scanbar { | 
| 147 |  |  | short   sampr;          /* sample area size (power of 2) */ | 
| 148 |  |  | short   nscans;         /* number of scanlines in this bar */ | 
| 149 |  |  | int     len;            /* individual scanline length */ | 
| 150 |  |  | struct scanbar  *next;  /* next higher resolution scanbar */ | 
| 151 |  |  | int     nread;          /* number of scanlines loaded */ | 
| 152 |  |  | /* followed by the scanline data */ | 
| 153 |  |  | } SCANBAR; | 
| 154 |  |  |  | 
| 155 |  |  | #define bscan(sb,y)     ((COLOR *)((sb)+1)+((y)%(sb)->nscans)*(sb)->len) | 
| 156 |  |  |  | 
| 157 |  |  | SCANBAR *rootbar;               /* root scan bar (lowest resolution) */ | 
| 158 |  |  |  | 
| 159 |  |  | float   *inpacuD;               /* input acuity data (cycles/degree) */ | 
| 160 |  |  |  | 
| 161 |  |  | #define tsampr(x,y)     inpacuD[(y)*fvxr+(x)] | 
| 162 |  |  |  | 
| 163 |  |  |  | 
| 164 |  |  | double | 
| 165 |  |  | hacuity(La)                     /* return visual acuity in cycles/degree */ | 
| 166 |  |  | double  La; | 
| 167 |  |  | {                               /* data due to S. Shaler (we should fit it!) */ | 
| 168 |  |  | #define NPOINTS 20 | 
| 169 |  |  | static float    l10lum[NPOINTS] = { | 
| 170 |  |  | -3.10503,-2.66403,-2.37703,-2.09303,-1.64403,-1.35803, | 
| 171 |  |  | -1.07403,-0.67203,-0.38503,-0.10103,0.29397,0.58097,0.86497, | 
| 172 |  |  | 1.25697,1.54397,1.82797,2.27597,2.56297,2.84697,3.24897 | 
| 173 |  |  | }; | 
| 174 |  |  | static float    resfreq[NPOINTS] = { | 
| 175 |  |  | 2.09,3.28,3.79,4.39,6.11,8.83,10.94,18.66,23.88,31.05,37.42, | 
| 176 |  |  | 37.68,41.60,43.16,45.30,47.00,48.43,48.32,51.06,51.09 | 
| 177 |  |  | }; | 
| 178 |  |  | double  l10La; | 
| 179 |  |  | register int    i; | 
| 180 |  |  | /* interpolate/extrapolate data */ | 
| 181 |  |  | l10La = log10(La); | 
| 182 |  |  | for (i = 0; i < NPOINTS-2 && l10lum[i+1] <= l10La; i++) | 
| 183 |  |  | ; | 
| 184 |  |  | return( ( (l10lum[i+1] - l10La)*resfreq[i] + | 
| 185 |  |  | (l10La - l10lum[i])*resfreq[i+1] ) / | 
| 186 |  |  | (l10lum[i+1] - l10lum[i]) ); | 
| 187 |  |  | #undef NPOINTS | 
| 188 |  |  | } | 
| 189 |  |  |  | 
| 190 |  |  |  | 
| 191 |  |  | COLOR * | 
| 192 |  |  | getascan(sb, y)                 /* find/read scanline y for scanbar sb */ | 
| 193 |  |  | register SCANBAR        *sb; | 
| 194 |  |  | int     y; | 
| 195 |  |  | { | 
| 196 |  |  | register COLOR  *sl0, *sl1, *mysl; | 
| 197 |  |  | register int    i; | 
| 198 |  |  |  | 
| 199 |  |  | if (y < sb->nread - sb->nscans) { | 
| 200 |  |  | fprintf(stderr, "%s: internal - cannot backspace in getascan\n", | 
| 201 |  |  | progname); | 
| 202 |  |  | exit(1); | 
| 203 |  |  | } | 
| 204 |  |  | for ( ; y >= sb->nread; sb->nread++) {          /* read as necessary */ | 
| 205 |  |  | mysl = bscan(sb, sb->nread); | 
| 206 |  |  | if (sb->sampr == 1) { | 
| 207 |  |  | if (freadscan(mysl, sb->len, infp) < 0) { | 
| 208 |  |  | fprintf(stderr, "%s: %s: scanline read error\n", | 
| 209 |  |  | progname, infn); | 
| 210 |  |  | exit(1); | 
| 211 |  |  | } | 
| 212 |  |  | } else { | 
| 213 |  |  | sl0 = getascan(sb->next, 2*y); | 
| 214 |  |  | sl1 = getascan(sb->next, 2*y+1); | 
| 215 |  |  | for (i = 0; i < sb->len; i++) { | 
| 216 |  |  | copycolor(mysl[i], sl0[2*i]); | 
| 217 |  |  | addcolor(mysl[i], sl0[2*i+1]); | 
| 218 |  |  | addcolor(mysl[i], sl1[2*i]); | 
| 219 |  |  | addcolor(mysl[i], sl1[2*i+1]); | 
| 220 |  |  | scalecolor(mysl[i], 0.25); | 
| 221 |  |  | } | 
| 222 |  |  | } | 
| 223 |  |  | } | 
| 224 |  |  | return(bscan(sb, y)); | 
| 225 |  |  | } | 
| 226 |  |  |  | 
| 227 |  |  |  | 
| 228 |  |  | acuscan(scln, y)                /* get acuity-sampled scanline */ | 
| 229 |  |  | COLOR   *scln; | 
| 230 |  |  | int     y; | 
| 231 |  |  | { | 
| 232 |  |  | double  sr; | 
| 233 |  |  | double  dx, dy; | 
| 234 |  |  | int     ix, iy; | 
| 235 |  |  | register int    x; | 
| 236 |  |  | /* compute foveal y position */ | 
| 237 |  |  | iy = dy = (y+.5)/numscans(&inpres)*fvyr - .5; | 
| 238 |  |  | if (iy >= fvyr-1) iy--; | 
| 239 |  |  | dy -= (double)iy; | 
| 240 |  |  | for (x = 0; x < scanlen(&inpres); x++) { | 
| 241 |  |  | /* compute foveal x position */ | 
| 242 |  |  | ix = dx = (x+.5)/scanlen(&inpres)*fvxr - .5; | 
| 243 |  |  | if (ix >= fvxr-1) ix--; | 
| 244 |  |  | dx -= (double)ix; | 
| 245 |  |  | /* interpolate sample rate */ | 
| 246 |  |  | sr = (1.-dy)*((1.-dx)*tsampr(ix,iy) + dx*tsampr(ix+1,iy)) + | 
| 247 |  |  | dy*((1.-dx)*tsampr(ix,iy+1) + dx*tsampr(ix+1,iy+1)); | 
| 248 |  |  |  | 
| 249 |  |  | acusample(scln[x], x, y, sr);   /* compute sample */ | 
| 250 |  |  | } | 
| 251 |  |  | } | 
| 252 |  |  |  | 
| 253 |  |  |  | 
| 254 |  |  | acusample(col, x, y, sr)        /* interpolate sample at (x,y) using rate sr */ | 
| 255 |  |  | COLOR   col; | 
| 256 |  |  | int     x, y; | 
| 257 |  |  | double  sr; | 
| 258 |  |  | { | 
| 259 |  |  | COLOR   c1; | 
| 260 |  |  | double  d; | 
| 261 |  |  | register SCANBAR        *sb0; | 
| 262 |  |  |  | 
| 263 |  |  | for (sb0 = rootbar; sb0->next != NULL && sb0->next->sampr > sr; | 
| 264 |  |  | sb0 = sb0->next) | 
| 265 |  |  | ; | 
| 266 |  |  | ascanval(col, x, y, sb0); | 
| 267 |  |  | if (sb0->next == NULL)          /* don't extrapolate highest */ | 
| 268 |  |  | return; | 
| 269 |  |  | ascanval(c1, x, y, sb0->next); | 
| 270 |  |  | d = (sb0->sampr - sr)/(sb0->sampr - sb0->next->sampr); | 
| 271 |  |  | scalecolor(col, 1.-d); | 
| 272 |  |  | scalecolor(c1, d); | 
| 273 |  |  | addcolor(col, c1); | 
| 274 |  |  | } | 
| 275 |  |  |  | 
| 276 |  |  |  | 
| 277 |  |  | ascanval(col, x, y, sb)         /* interpolate scanbar at orig. coords (x,y) */ | 
| 278 |  |  | COLOR   col; | 
| 279 |  |  | int     x, y; | 
| 280 |  |  | SCANBAR *sb; | 
| 281 |  |  | { | 
| 282 |  |  | COLOR   *sl0, *sl1, c1, c1y; | 
| 283 |  |  | double  dx, dy; | 
| 284 |  |  | int     ix, iy; | 
| 285 |  |  |  | 
| 286 |  |  | ix = dx = (x+.5)/sb->sampr - .5; | 
| 287 |  |  | if (ix >= sb->len-1) ix--; | 
| 288 |  |  | dx -= (double)ix; | 
| 289 |  |  | iy = dy = (y+.5)/sb->sampr - .5; | 
| 290 |  |  | if (iy >= numscans(&inpres)/sb->sampr-1) iy--; | 
| 291 |  |  | dy -= (double)iy; | 
| 292 |  |  | /* get scanlines */ | 
| 293 |  |  | sl0 = getascan(sb, iy); | 
| 294 |  |  | sl1 = getascan(sb, iy+1); | 
| 295 |  |  | /* 2D linear interpolation */ | 
| 296 |  |  | copycolor(col, sl0[ix]); | 
| 297 |  |  | scalecolor(col, 1.-dx); | 
| 298 |  |  | copycolor(c1, sl0[ix+1]); | 
| 299 |  |  | scalecolor(c1, dx); | 
| 300 |  |  | addcolor(col, c1); | 
| 301 |  |  | copycolor(c1y, sl1[ix]); | 
| 302 |  |  | scalecolor(c1y, 1.-dx); | 
| 303 |  |  | copycolor(c1, sl1[ix+1]); | 
| 304 |  |  | scalecolor(c1, dx); | 
| 305 |  |  | addcolor(c1y, c1); | 
| 306 |  |  | scalecolor(col, 1.-dy); | 
| 307 |  |  | scalecolor(c1y, dy); | 
| 308 |  |  | addcolor(col, c1y); | 
| 309 |  |  | } | 
| 310 |  |  |  | 
| 311 |  |  |  | 
| 312 |  |  | SCANBAR * | 
| 313 |  |  | sballoc(sr, ns, sl)             /* allocate scanbar */ | 
| 314 |  |  | int     sr;             /* sampling rate */ | 
| 315 |  |  | int     ns;             /* number of scanlines */ | 
| 316 |  |  | int     sl;             /* original scanline length */ | 
| 317 |  |  | { | 
| 318 |  |  | register SCANBAR        *sb; | 
| 319 |  |  |  | 
| 320 |  |  | sb = (SCANBAR *)malloc(sizeof(SCANBAR)+(sl/sr)*ns*sizeof(COLOR)); | 
| 321 |  |  | if (sb == NULL) | 
| 322 |  |  | syserror("malloc"); | 
| 323 |  |  | sb->nscans = ns; | 
| 324 |  |  | sb->len = sl/sr; | 
| 325 |  |  | sb->nread = 0; | 
| 326 |  |  | if ((sb->sampr = sr) > 1) | 
| 327 |  |  | sb->next = sballoc(sr/2, ns*2, sl); | 
| 328 |  |  | else | 
| 329 |  |  | sb->next = NULL; | 
| 330 |  |  | return(sb); | 
| 331 |  |  | } | 
| 332 |  |  |  | 
| 333 |  |  |  | 
| 334 |  |  | initacuity()                    /* initialize variable acuity sampling */ | 
| 335 |  |  | { | 
| 336 |  |  | FVECT   diffx, diffy, cp; | 
| 337 |  |  | double  omega, maxsr; | 
| 338 |  |  | register int    x, y, i; | 
| 339 |  |  |  | 
| 340 |  |  | compraydir();                   /* compute ray directions */ | 
| 341 |  |  |  | 
| 342 |  |  | inpacuD = (float *)malloc(fvxr*fvyr*sizeof(float)); | 
| 343 |  |  | if (inpacuD == NULL) | 
| 344 |  |  | syserror("malloc"); | 
| 345 |  |  | maxsr = 1.;                     /* compute internal sample rates */ | 
| 346 |  |  | for (y = 1; y < fvyr-1; y++) | 
| 347 |  |  | for (x = 1; x < fvxr-1; x++) { | 
| 348 |  |  | for (i = 0; i < 3; i++) { | 
| 349 |  |  | diffx[i] = 0.5*fvxr/scanlen(&inpres) * | 
| 350 |  |  | (rdirscan(y)[x+1][i] - | 
| 351 |  |  | rdirscan(y)[x-1][i]); | 
| 352 |  |  | diffy[i] = 0.5*fvyr/numscans(&inpres) * | 
| 353 |  |  | (rdirscan(y+1)[x][i] - | 
| 354 |  |  | rdirscan(y-1)[x][i]); | 
| 355 |  |  | } | 
| 356 |  |  | fcross(cp, diffx, diffy); | 
| 357 |  |  | omega = 0.5 * sqrt(DOT(cp,cp)); | 
| 358 |  |  | tsampr(x,y) = PI/180. / sqrt(omega) / | 
| 359 |  |  | hacuity(plum(fovscan(y)[x])); | 
| 360 |  |  | if (tsampr(x,y) > maxsr) | 
| 361 |  |  | maxsr = tsampr(x,y); | 
| 362 |  |  | } | 
| 363 |  |  | /* copy perimeter (easier) */ | 
| 364 |  |  | for (x = 1; x < fvxr-1; x++) { | 
| 365 |  |  | tsampr(x,0) = tsampr(x,1); | 
| 366 |  |  | tsampr(x,fvyr-1) = tsampr(x,fvyr-2); | 
| 367 |  |  | } | 
| 368 |  |  | for (y = 0; y < fvyr; y++) { | 
| 369 |  |  | tsampr(y,0) = tsampr(y,1); | 
| 370 |  |  | tsampr(y,fvxr-1) = tsampr(y,fvxr-2); | 
| 371 |  |  | } | 
| 372 |  |  | /* initialize with next power of two */ | 
| 373 |  |  | rootbar = sballoc(2<<(int)(log(maxsr)/log(2.)), 2, scanlen(&inpres)); | 
| 374 | greg | 3.1 | } |