| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: pcond4.c,v 3.16 2003/02/22 02:07:27 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
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* Routines for veiling glare and loss of acuity. |
| 6 |
*/ |
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|
| 8 |
#include "pcond.h" |
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|
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/************** VEILING STUFF *****************/ |
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|
| 12 |
#define VADAPT 0.08 /* fraction of adaptation from veil */ |
| 13 |
|
| 14 |
static COLOR *veilimg = NULL; /* veiling image */ |
| 15 |
|
| 16 |
#define veilscan(y) (veilimg+(y)*fvxr) |
| 17 |
|
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static float (*raydir)[3] = NULL; /* ray direction for each pixel */ |
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|
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#define rdirscan(y) (raydir+(y)*fvxr) |
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|
| 22 |
static void compraydir(void); |
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#if ADJ_VEIL |
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static void smoothveil(void); |
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#endif |
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|
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|
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static void |
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compraydir(void) /* compute ray directions */ |
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{ |
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FVECT rorg, rdir; |
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double h, v; |
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register int x, y; |
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|
| 35 |
if (raydir != NULL) /* already done? */ |
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return; |
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raydir = (float (*)[3])malloc(fvxr*fvyr*3*sizeof(float)); |
| 38 |
if (raydir == NULL) |
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syserror("malloc"); |
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|
| 41 |
for (y = 0; y < fvyr; y++) { |
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switch (inpres.rt) { |
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case YMAJOR: case YMAJOR|XDECR: |
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v = (y+.5)/fvyr; break; |
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case YMAJOR|YDECR: case YMAJOR|YDECR|XDECR: |
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v = 1. - (y+.5)/fvyr; break; |
| 47 |
case 0: case YDECR: |
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h = (y+.5)/fvyr; break; |
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case XDECR: case XDECR|YDECR: |
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h = 1. - (y+.5)/fvyr; break; |
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} |
| 52 |
for (x = 0; x < fvxr; x++) { |
| 53 |
switch (inpres.rt) { |
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case YMAJOR: case YMAJOR|YDECR: |
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h = (x+.5)/fvxr; break; |
| 56 |
case YMAJOR|XDECR: case YMAJOR|XDECR|YDECR: |
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h = 1. - (x+.5)/fvxr; break; |
| 58 |
case 0: case XDECR: |
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v = (x+.5)/fvxr; break; |
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case YDECR: case YDECR|XDECR: |
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v = 1. - (x+.5)/fvxr; break; |
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} |
| 63 |
if (viewray(rorg, rdir, &ourview, h, v) |
| 64 |
>= -FTINY) { |
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rdirscan(y)[x][0] = rdir[0]; |
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rdirscan(y)[x][1] = rdir[1]; |
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rdirscan(y)[x][2] = rdir[2]; |
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} else { |
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rdirscan(y)[x][0] = |
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rdirscan(y)[x][1] = |
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rdirscan(y)[x][2] = 0.0; |
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} |
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} |
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} |
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} |
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|
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|
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extern void |
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compveil(void) /* compute veiling image */ |
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{ |
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double t2, t2sum; |
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COLOR ctmp, vsum; |
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int px, py; |
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register int x, y; |
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|
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if (veilimg != NULL) /* already done? */ |
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return; |
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/* compute ray directions */ |
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compraydir(); |
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/* compute veil image */ |
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veilimg = (COLOR *)malloc(fvxr*fvyr*sizeof(COLOR)); |
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if (veilimg == NULL) |
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syserror("malloc"); |
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for (py = 0; py < fvyr; py++) |
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for (px = 0; px < fvxr; px++) { |
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t2sum = 0.; |
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setcolor(vsum, 0., 0., 0.); |
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for (y = 0; y < fvyr; y++) |
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for (x = 0; x < fvxr; x++) { |
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if (x == px && y == py) continue; |
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t2 = DOT(rdirscan(py)[px], |
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rdirscan(y)[x]); |
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if (t2 <= FTINY) continue; |
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/* use approximation instead |
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t3 = acos(t2); |
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t2 = t2/(t3*t3); |
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*/ |
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t2 *= .5 / (1. - t2); |
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copycolor(ctmp, fovscan(y)[x]); |
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scalecolor(ctmp, t2); |
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addcolor(vsum, ctmp); |
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t2sum += t2; |
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} |
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/* VADAPT of original is subtracted in addveil() */ |
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if (t2sum > FTINY) |
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scalecolor(vsum, VADAPT/t2sum); |
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copycolor(veilscan(py)[px], vsum); |
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} |
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/* modify FOV sample image */ |
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for (y = 0; y < fvyr; y++) |
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for (x = 0; x < fvxr; x++) { |
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scalecolor(fovscan(y)[x], 1.-VADAPT); |
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addcolor(fovscan(y)[x], veilscan(y)[x]); |
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} |
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comphist(); /* recompute histogram */ |
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} |
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|
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|
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#if ADJ_VEIL |
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/* |
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* The following veil adjustment was added to compensate for |
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* the fact that contrast reduction gets confused with veil |
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* in the human visual system. Therefore, we reduce the |
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* veil in portions of the image where our mapping has |
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* already reduced contrast below the target value. |
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* This gets called after the intial veil has been computed |
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* and added to the foveal image, and the mapping has been |
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* determined. |
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*/ |
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extern void |
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adjveil(void) /* adjust veil image */ |
| 142 |
{ |
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float *crfptr = crfimg; |
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COLOR *fovptr = fovimg; |
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COLOR *veilptr = veilimg; |
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double s2nits = 1./inpexp; |
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double vl, vl2, fovl, vlsum; |
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double deltavc[3]; |
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int i, j; |
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|
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if (lumf == rgblum) |
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s2nits *= WHTEFFICACY; |
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|
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for (i = fvxr*fvyr; i--; crfptr++, fovptr++, veilptr++) { |
| 155 |
if (crfptr[0] >= 0.95) |
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continue; |
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vl = plum(veilptr[0]); |
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fovl = (plum(fovptr[0]) - vl) * (1./(1.-VADAPT)); |
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if (vl <= 0.05*fovl) |
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continue; |
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vlsum = vl; |
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for (j = 2; j < 11; j++) { |
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vlsum += crfptr[0]*vl - (1.0 - crfptr[0])*fovl; |
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vl2 = vlsum / (double)j; |
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if (vl2 < 0.0) |
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vl2 = 0.0; |
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crfptr[0] = crfactor(fovl + vl2); |
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} |
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/* desaturation code causes color fringes at this level */ |
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for (j = 3; j--; ) { |
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double vc = colval(veilptr[0],j); |
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double fovc = (colval(fovptr[0],j) - vc) * |
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(1./(1.-VADAPT)); |
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deltavc[j] = (1.-crfptr[0])*(fovl/s2nits - fovc); |
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if (vc + deltavc[j] < 0.0) |
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break; |
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} |
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if (j < 0) |
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addcolor(veilptr[0], deltavc); |
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else |
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scalecolor(veilptr[0], vl2/vl); |
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} |
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smoothveil(); /* smooth our result */ |
| 184 |
} |
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|
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|
| 187 |
static void |
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smoothveil(void) /* smooth veil image */ |
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{ |
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COLOR *nveilimg; |
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COLOR *ovptr, *nvptr; |
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int x, y, i; |
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|
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nveilimg = (COLOR *)malloc(fvxr*fvyr*sizeof(COLOR)); |
| 195 |
if (nveilimg == NULL) |
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return; |
| 197 |
for (y = 1; y < fvyr-1; y++) { |
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ovptr = veilimg + y*fvxr + 1; |
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nvptr = nveilimg + y*fvxr + 1; |
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for (x = 1; x < fvxr-1; x++, ovptr++, nvptr++) |
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for (i = 3; i--; ) |
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nvptr[0][i] = 0.5 * ovptr[0][i] |
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+ (1./12.) * |
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(ovptr[-1][i] + ovptr[-fvxr][i] + |
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ovptr[1][i] + ovptr[fvxr][i]) |
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+ (1./24.) * |
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(ovptr[-fvxr-1][i] + ovptr[-fvxr+1][i] + |
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ovptr[fvxr-1][i] + ovptr[fvxr+1][i]); |
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} |
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ovptr = veilimg + 1; |
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nvptr = nveilimg + 1; |
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for (x = 1; x < fvxr-1; x++, ovptr++, nvptr++) |
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for (i = 3; i--; ) |
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nvptr[0][i] = 0.5 * ovptr[0][i] |
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+ (1./9.) * |
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(ovptr[-1][i] + ovptr[1][i] + ovptr[fvxr][i]) |
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+ (1./12.) * |
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(ovptr[fvxr-1][i] + ovptr[fvxr+1][i]); |
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ovptr = veilimg + (fvyr-1)*fvxr + 1; |
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nvptr = nveilimg + (fvyr-1)*fvxr + 1; |
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for (x = 1; x < fvxr-1; x++, ovptr++, nvptr++) |
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for (i = 3; i--; ) |
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nvptr[0][i] = 0.5 * ovptr[0][i] |
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+ (1./9.) * |
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(ovptr[-1][i] + ovptr[1][i] + ovptr[-fvxr][i]) |
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+ (1./12.) * |
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(ovptr[-fvxr-1][i] + ovptr[-fvxr+1][i]); |
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ovptr = veilimg + fvxr; |
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nvptr = nveilimg + fvxr; |
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for (y = 1; y < fvyr-1; y++, ovptr += fvxr, nvptr += fvxr) |
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for (i = 3; i--; ) |
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nvptr[0][i] = 0.5 * ovptr[0][i] |
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+ (1./9.) * |
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(ovptr[-fvxr][i] + ovptr[1][i] + ovptr[fvxr][i]) |
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+ (1./12.) * |
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(ovptr[-fvxr+1][i] + ovptr[fvxr+1][i]); |
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ovptr = veilimg + fvxr - 1; |
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nvptr = nveilimg + fvxr - 1; |
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for (y = 1; y < fvyr-1; y++, ovptr += fvxr, nvptr += fvxr) |
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for (i = 3; i--; ) |
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nvptr[0][i] = 0.5 * ovptr[0][i] |
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+ (1./9.) * |
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(ovptr[-fvxr][i] + ovptr[-1][i] + ovptr[fvxr][i]) |
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+ (1./12.) * |
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(ovptr[-fvxr-1][i] + ovptr[fvxr-1][i]); |
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for (i = 3; i--; ) { |
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nveilimg[0][i] = veilimg[0][i]; |
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nveilimg[fvxr-1][i] = veilimg[fvxr-1][i]; |
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nveilimg[(fvyr-1)*fvxr][i] = veilimg[(fvyr-1)*fvxr][i]; |
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nveilimg[fvyr*fvxr-1][i] = veilimg[fvyr*fvxr-1][i]; |
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} |
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free((void *)veilimg); |
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veilimg = nveilimg; |
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} |
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#endif |
| 256 |
|
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extern void |
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addveil( /* add veil to scanline */ |
| 259 |
COLOR *sl, |
| 260 |
int y |
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) |
| 262 |
{ |
| 263 |
int vx, vy; |
| 264 |
double dx, dy; |
| 265 |
double lv, uv; |
| 266 |
register int x, i; |
| 267 |
|
| 268 |
vy = dy = (y+.5)/numscans(&inpres)*fvyr - .5; |
| 269 |
while (vy >= fvyr-1) vy--; |
| 270 |
dy -= (double)vy; |
| 271 |
for (x = 0; x < scanlen(&inpres); x++) { |
| 272 |
vx = dx = (x+.5)/scanlen(&inpres)*fvxr - .5; |
| 273 |
while (vx >= fvxr-1) vx--; |
| 274 |
dx -= (double)vx; |
| 275 |
for (i = 0; i < 3; i++) { |
| 276 |
lv = (1.-dy)*colval(veilscan(vy)[vx],i) + |
| 277 |
dy*colval(veilscan(vy+1)[vx],i); |
| 278 |
uv = (1.-dy)*colval(veilscan(vy)[vx+1],i) + |
| 279 |
dy*colval(veilscan(vy+1)[vx+1],i); |
| 280 |
colval(sl[x],i) = (1.-VADAPT)*colval(sl[x],i) + |
| 281 |
(1.-dx)*lv + dx*uv; |
| 282 |
} |
| 283 |
} |
| 284 |
} |
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|
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|
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/****************** ACUITY STUFF *******************/ |
| 288 |
|
| 289 |
typedef struct { |
| 290 |
short sampe; /* sample area size (exponent of 2) */ |
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short nscans; /* number of scanlines in this bar */ |
| 292 |
int len; /* individual scanline length */ |
| 293 |
int nread; /* number of scanlines loaded */ |
| 294 |
COLOR *sdata; /* scanbar data */ |
| 295 |
} SCANBAR; |
| 296 |
|
| 297 |
#define bscan(sb,y) ((COLOR *)(sb)->sdata+((y)%(sb)->nscans)*(sb)->len) |
| 298 |
|
| 299 |
SCANBAR *rootbar; /* root scan bar (lowest resolution) */ |
| 300 |
|
| 301 |
float *inpacuD; /* input acuity data (cycles/degree) */ |
| 302 |
|
| 303 |
#define tsampr(x,y) inpacuD[(y)*fvxr+(x)] |
| 304 |
|
| 305 |
static COLOR * getascan(SCANBAR *sb, int y); |
| 306 |
static void acusample(COLOR col, int x, int y, double sr); |
| 307 |
static void ascanval(COLOR col, int x, int y, SCANBAR *sb); |
| 308 |
static SCANBAR *sballoc(int se, int ns, int sl); |
| 309 |
|
| 310 |
extern double |
| 311 |
hacuity( /* return visual acuity in cycles/degree */ |
| 312 |
double La |
| 313 |
) |
| 314 |
{ |
| 315 |
/* functional fit */ |
| 316 |
return(17.25*atan(1.4*log10(La) + 0.35) + 25.72); |
| 317 |
} |
| 318 |
|
| 319 |
|
| 320 |
static COLOR * |
| 321 |
getascan( /* find/read scanline y for scanbar sb */ |
| 322 |
register SCANBAR *sb, |
| 323 |
int y |
| 324 |
) |
| 325 |
{ |
| 326 |
register COLOR *sl0, *sl1, *mysl; |
| 327 |
register int i; |
| 328 |
|
| 329 |
if (y < sb->nread - sb->nscans) /* too far back? */ |
| 330 |
return(NULL); |
| 331 |
for ( ; y >= sb->nread; sb->nread++) { /* read as necessary */ |
| 332 |
mysl = bscan(sb, sb->nread); |
| 333 |
if (sb->sampe == 0) { |
| 334 |
if (freadscan(mysl, sb->len, infp) < 0) { |
| 335 |
fprintf(stderr, "%s: %s: scanline read error\n", |
| 336 |
progname, infn); |
| 337 |
exit(1); |
| 338 |
} |
| 339 |
} else { |
| 340 |
sl0 = getascan(sb+1, 2*y); |
| 341 |
if (sl0 == NULL) |
| 342 |
return(NULL); |
| 343 |
sl1 = getascan(sb+1, 2*y+1); |
| 344 |
for (i = 0; i < sb->len; i++) { |
| 345 |
copycolor(mysl[i], sl0[2*i]); |
| 346 |
addcolor(mysl[i], sl0[2*i+1]); |
| 347 |
addcolor(mysl[i], sl1[2*i]); |
| 348 |
addcolor(mysl[i], sl1[2*i+1]); |
| 349 |
scalecolor(mysl[i], 0.25); |
| 350 |
} |
| 351 |
} |
| 352 |
} |
| 353 |
return(bscan(sb, y)); |
| 354 |
} |
| 355 |
|
| 356 |
|
| 357 |
extern void |
| 358 |
acuscan( /* get acuity-sampled scanline */ |
| 359 |
COLOR *scln, |
| 360 |
int y |
| 361 |
) |
| 362 |
{ |
| 363 |
double sr; |
| 364 |
double dx, dy; |
| 365 |
int ix, iy; |
| 366 |
register int x; |
| 367 |
/* compute foveal y position */ |
| 368 |
iy = dy = (y+.5)/numscans(&inpres)*fvyr - .5; |
| 369 |
while (iy >= fvyr-1) iy--; |
| 370 |
dy -= (double)iy; |
| 371 |
for (x = 0; x < scanlen(&inpres); x++) { |
| 372 |
/* compute foveal x position */ |
| 373 |
ix = dx = (x+.5)/scanlen(&inpres)*fvxr - .5; |
| 374 |
while (ix >= fvxr-1) ix--; |
| 375 |
dx -= (double)ix; |
| 376 |
/* interpolate sample rate */ |
| 377 |
sr = (1.-dy)*((1.-dx)*tsampr(ix,iy) + dx*tsampr(ix+1,iy)) + |
| 378 |
dy*((1.-dx)*tsampr(ix,iy+1) + dx*tsampr(ix+1,iy+1)); |
| 379 |
|
| 380 |
acusample(scln[x], x, y, sr); /* compute sample */ |
| 381 |
} |
| 382 |
} |
| 383 |
|
| 384 |
|
| 385 |
static void |
| 386 |
acusample( /* interpolate sample at (x,y) using rate sr */ |
| 387 |
COLOR col, |
| 388 |
int x, |
| 389 |
int y, |
| 390 |
double sr |
| 391 |
) |
| 392 |
{ |
| 393 |
COLOR c1; |
| 394 |
double d; |
| 395 |
register SCANBAR *sb0; |
| 396 |
|
| 397 |
for (sb0 = rootbar; sb0->sampe != 0 && 1<<sb0[1].sampe > sr; sb0++) |
| 398 |
; |
| 399 |
ascanval(col, x, y, sb0); |
| 400 |
if (sb0->sampe == 0) /* don't extrapolate highest */ |
| 401 |
return; |
| 402 |
ascanval(c1, x, y, sb0+1); |
| 403 |
d = ((1<<sb0->sampe) - sr)/(1<<sb0[1].sampe); |
| 404 |
scalecolor(col, 1.-d); |
| 405 |
scalecolor(c1, d); |
| 406 |
addcolor(col, c1); |
| 407 |
} |
| 408 |
|
| 409 |
|
| 410 |
static void |
| 411 |
ascanval( /* interpolate scanbar at orig. coords (x,y) */ |
| 412 |
COLOR col, |
| 413 |
int x, |
| 414 |
int y, |
| 415 |
SCANBAR *sb |
| 416 |
) |
| 417 |
{ |
| 418 |
COLOR *sl0, *sl1, c1, c1y; |
| 419 |
double dx, dy; |
| 420 |
int ix, iy; |
| 421 |
|
| 422 |
if (sb->sampe == 0) { /* no need to interpolate */ |
| 423 |
sl0 = getascan(sb, y); |
| 424 |
copycolor(col, sl0[x]); |
| 425 |
return; |
| 426 |
} |
| 427 |
/* compute coordinates for sb */ |
| 428 |
ix = dx = (x+.5)/(1<<sb->sampe) - .5; |
| 429 |
while (ix >= sb->len-1) ix--; |
| 430 |
dx -= (double)ix; |
| 431 |
iy = dy = (y+.5)/(1<<sb->sampe) - .5; |
| 432 |
while (iy >= (numscans(&inpres)>>sb->sampe)-1) iy--; |
| 433 |
dy -= (double)iy; |
| 434 |
/* get scanlines */ |
| 435 |
sl0 = getascan(sb, iy); |
| 436 |
#ifdef DEBUG |
| 437 |
if (sl0 == NULL) |
| 438 |
error(INTERNAL, "cannot backspace in ascanval"); |
| 439 |
#endif |
| 440 |
sl1 = getascan(sb, iy+1); |
| 441 |
/* 2D linear interpolation */ |
| 442 |
copycolor(col, sl0[ix]); |
| 443 |
scalecolor(col, 1.-dx); |
| 444 |
copycolor(c1, sl0[ix+1]); |
| 445 |
scalecolor(c1, dx); |
| 446 |
addcolor(col, c1); |
| 447 |
copycolor(c1y, sl1[ix]); |
| 448 |
scalecolor(c1y, 1.-dx); |
| 449 |
copycolor(c1, sl1[ix+1]); |
| 450 |
scalecolor(c1, dx); |
| 451 |
addcolor(c1y, c1); |
| 452 |
scalecolor(col, 1.-dy); |
| 453 |
scalecolor(c1y, dy); |
| 454 |
addcolor(col, c1y); |
| 455 |
for (ix = 0; ix < 3; ix++) /* make sure no negative */ |
| 456 |
if (colval(col,ix) < 0.) |
| 457 |
colval(col,ix) = 0.; |
| 458 |
} |
| 459 |
|
| 460 |
|
| 461 |
static SCANBAR * |
| 462 |
sballoc( /* allocate scanbar */ |
| 463 |
int se, /* sampling rate exponent */ |
| 464 |
int ns, /* number of scanlines */ |
| 465 |
int sl /* original scanline length */ |
| 466 |
) |
| 467 |
{ |
| 468 |
SCANBAR *sbarr; |
| 469 |
register SCANBAR *sb; |
| 470 |
|
| 471 |
sbarr = sb = (SCANBAR *)malloc((se+1)*sizeof(SCANBAR)); |
| 472 |
if (sb == NULL) |
| 473 |
syserror("malloc"); |
| 474 |
do { |
| 475 |
sb->len = sl>>se; |
| 476 |
if (sb->len <= 0) |
| 477 |
continue; |
| 478 |
sb->sampe = se; |
| 479 |
sb->nscans = ns; |
| 480 |
sb->sdata = (COLOR *)malloc(sb->len*ns*sizeof(COLOR)); |
| 481 |
if (sb->sdata == NULL) |
| 482 |
syserror("malloc"); |
| 483 |
sb->nread = 0; |
| 484 |
ns <<= 1; |
| 485 |
sb++; |
| 486 |
} while (--se >= 0); |
| 487 |
return(sbarr); |
| 488 |
} |
| 489 |
|
| 490 |
|
| 491 |
extern void |
| 492 |
initacuity(void) /* initialize variable acuity sampling */ |
| 493 |
{ |
| 494 |
FVECT diffx, diffy, cp; |
| 495 |
double omega, maxsr; |
| 496 |
register int x, y, i; |
| 497 |
|
| 498 |
compraydir(); /* compute ray directions */ |
| 499 |
|
| 500 |
inpacuD = (float *)malloc(fvxr*fvyr*sizeof(float)); |
| 501 |
if (inpacuD == NULL) |
| 502 |
syserror("malloc"); |
| 503 |
maxsr = 1.; /* compute internal sample rates */ |
| 504 |
for (y = 1; y < fvyr-1; y++) |
| 505 |
for (x = 1; x < fvxr-1; x++) { |
| 506 |
for (i = 0; i < 3; i++) { |
| 507 |
diffx[i] = 0.5*fvxr/scanlen(&inpres) * |
| 508 |
(rdirscan(y)[x+1][i] - |
| 509 |
rdirscan(y)[x-1][i]); |
| 510 |
diffy[i] = 0.5*fvyr/numscans(&inpres) * |
| 511 |
(rdirscan(y+1)[x][i] - |
| 512 |
rdirscan(y-1)[x][i]); |
| 513 |
} |
| 514 |
fcross(cp, diffx, diffy); |
| 515 |
omega = 0.5 * sqrt(DOT(cp,cp)); |
| 516 |
if (omega <= FTINY*FTINY) |
| 517 |
tsampr(x,y) = 1.; |
| 518 |
else if ((tsampr(x,y) = PI/180. / sqrt(omega) / |
| 519 |
hacuity(plum(fovscan(y)[x]))) > maxsr) |
| 520 |
maxsr = tsampr(x,y); |
| 521 |
} |
| 522 |
/* copy perimeter (easier) */ |
| 523 |
for (x = 1; x < fvxr-1; x++) { |
| 524 |
tsampr(x,0) = tsampr(x,1); |
| 525 |
tsampr(x,fvyr-1) = tsampr(x,fvyr-2); |
| 526 |
} |
| 527 |
for (y = 0; y < fvyr; y++) { |
| 528 |
tsampr(0,y) = tsampr(1,y); |
| 529 |
tsampr(fvxr-1,y) = tsampr(fvxr-2,y); |
| 530 |
} |
| 531 |
/* initialize with next power of two */ |
| 532 |
rootbar = sballoc((int)(log(maxsr)/log(2.))+1, 2, scanlen(&inpres)); |
| 533 |
} |
