20 |
|
float cumf[HISTRES+1]; /* cumulative distribution function */ |
21 |
|
|
22 |
|
|
23 |
+ |
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 |
+ |
FIXHUNK*2*sizeof(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. - xr*xr - yr*yr; |
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 |
|
mkcumf() /* make cumulative distribution function */ |
155 |
|
{ |
156 |
|
register int i; |