1 |
greg |
2.10 |
/* Copyright (c) 1993 Regents of the University of California */ |
2 |
greg |
1.1 |
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3 |
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#ifndef lint |
4 |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
6 |
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7 |
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/* |
8 |
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* pf3.c - routines for gaussian and box filtering |
9 |
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* |
10 |
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* 8/13/86 |
11 |
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*/ |
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13 |
greg |
2.7 |
#include "standard.h" |
14 |
greg |
1.1 |
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15 |
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#include "color.h" |
16 |
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17 |
greg |
2.9 |
#define TEPS 0.2 /* threshold proximity goal */ |
18 |
greg |
2.10 |
#define REPS 0.1 /* radius proximity goal */ |
19 |
greg |
1.1 |
|
20 |
greg |
2.7 |
extern double CHECKRAD; /* radius over which gaussian is summed */ |
21 |
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22 |
greg |
1.1 |
extern double rad; /* output pixel radius for filtering */ |
23 |
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24 |
greg |
2.7 |
extern double thresh; /* maximum contribution for subpixel */ |
25 |
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26 |
greg |
1.1 |
extern int nrows; /* number of rows for output */ |
27 |
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extern int ncols; /* number of columns for output */ |
28 |
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29 |
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extern int xres, yres; /* resolution of input */ |
30 |
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31 |
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extern double x_c, y_r; /* conversion factors */ |
32 |
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33 |
greg |
2.7 |
extern int xrad; /* x search radius */ |
34 |
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extern int yrad; /* y search radius */ |
35 |
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extern int xbrad; /* x box size */ |
36 |
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extern int ybrad; /* y box size */ |
37 |
greg |
1.1 |
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38 |
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extern int barsize; /* size of input scan bar */ |
39 |
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extern COLOR **scanin; /* input scan bar */ |
40 |
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extern COLOR *scanout; /* output scan line */ |
41 |
greg |
2.7 |
extern COLOR **scoutbar; /* output scan bar (if thresh > 0) */ |
42 |
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extern float **greybar; /* grey-averaged input values */ |
43 |
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extern int obarsize; /* size of output scan bar */ |
44 |
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extern int orad; /* output window radius */ |
45 |
greg |
1.1 |
|
46 |
greg |
2.12 |
extern int wrapfilt; /* wrap filter horizontally? */ |
47 |
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48 |
greg |
1.1 |
extern char *progname; |
49 |
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50 |
greg |
2.5 |
float *gausstable; /* gauss lookup table */ |
51 |
greg |
1.1 |
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52 |
greg |
2.7 |
float *ringsum; /* sum of ring values */ |
53 |
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short *ringwt; /* weight (count) of ring values */ |
54 |
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short *ringndx; /* ring index table */ |
55 |
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float *warr; /* array of pixel weights */ |
56 |
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57 |
greg |
2.12 |
extern double (*ourbright)(); /* brightness computation function */ |
58 |
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59 |
greg |
2.7 |
double pickfilt(); |
60 |
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61 |
greg |
2.6 |
#define lookgauss(x) gausstable[(int)(10.*(x)+.5)] |
62 |
greg |
1.1 |
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63 |
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64 |
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initmask() /* initialize gaussian lookup table */ |
65 |
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{ |
66 |
greg |
2.7 |
int gtabsiz; |
67 |
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double gaussN; |
68 |
greg |
2.5 |
double d; |
69 |
greg |
1.1 |
register int x; |
70 |
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71 |
greg |
2.7 |
gtabsiz = 150*CHECKRAD; |
72 |
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gausstable = (float *)malloc(gtabsiz*sizeof(float)); |
73 |
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if (gausstable == NULL) |
74 |
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goto memerr; |
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d = x_c*y_r*0.25/(rad*rad); |
76 |
greg |
2.5 |
gausstable[0] = exp(-d)/sqrt(d); |
77 |
greg |
2.7 |
for (x = 1; x < gtabsiz; x++) |
78 |
greg |
2.5 |
if ((gausstable[x] = exp(-x*0.1)/sqrt(x*0.1)) > gausstable[0]) |
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gausstable[x] = gausstable[0]; |
80 |
greg |
2.7 |
if (obarsize == 0) |
81 |
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return; |
82 |
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/* compute integral of filter */ |
83 |
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gaussN = PI*sqrt(d)*exp(-d); /* plateau */ |
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for (d = sqrt(d)+0.05; d <= 1.25*CHECKRAD; d += 0.1) |
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gaussN += 0.1*2.0*PI*exp(-d*d); |
86 |
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/* normalize filter */ |
87 |
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gaussN = x_c*y_r/(rad*rad*gaussN); |
88 |
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for (x = 0; x < gtabsiz; x++) |
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gausstable[x] *= gaussN; |
90 |
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/* create ring averages table */ |
91 |
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ringndx = (short *)malloc((2*orad*orad+1)*sizeof(short)); |
92 |
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if (ringndx == NULL) |
93 |
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goto memerr; |
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for (x = 2*orad*orad+1; --x > orad*orad; ) |
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ringndx[x] = -1; |
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do |
97 |
greg |
2.8 |
ringndx[x] = sqrt((double)x); |
98 |
greg |
2.7 |
while (x--); |
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ringsum = (float *)malloc((orad+1)*sizeof(float)); |
100 |
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ringwt = (short *)malloc((orad+1)*sizeof(short)); |
101 |
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warr = (float *)malloc(obarsize*obarsize*sizeof(float)); |
102 |
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if (ringsum == NULL | ringwt == 0 | warr == NULL) |
103 |
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goto memerr; |
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return; |
105 |
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memerr: |
106 |
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fprintf(stderr, "%s: out of memory in initmask\n", progname); |
107 |
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quit(1); |
108 |
greg |
1.1 |
} |
109 |
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110 |
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111 |
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dobox(csum, xcent, ycent, c, r) /* simple box filter */ |
112 |
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COLOR csum; |
113 |
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int xcent, ycent; |
114 |
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int c, r; |
115 |
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{ |
116 |
greg |
2.6 |
int wsum; |
117 |
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double d; |
118 |
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int y; |
119 |
greg |
2.12 |
register int x, offs; |
120 |
greg |
2.2 |
register COLOR *scan; |
121 |
greg |
2.7 |
|
122 |
greg |
1.1 |
wsum = 0; |
123 |
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setcolor(csum, 0.0, 0.0, 0.0); |
124 |
greg |
2.7 |
for (y = ycent+1-ybrad; y <= ycent+ybrad; y++) { |
125 |
greg |
2.4 |
if (y < 0) continue; |
126 |
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if (y >= yres) break; |
127 |
greg |
2.13 |
d = y_r < 1.0 ? y_r*y - (r+.5) : (double)(y - ycent); |
128 |
greg |
2.7 |
if (d < -0.5) continue; |
129 |
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if (d >= 0.5) break; |
130 |
greg |
1.1 |
scan = scanin[y%barsize]; |
131 |
greg |
2.7 |
for (x = xcent+1-xbrad; x <= xcent+xbrad; x++) { |
132 |
greg |
2.12 |
offs = x < 0 ? xres : x >= xres ? -xres : 0; |
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if (offs && !wrapfilt) |
134 |
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continue; |
135 |
greg |
2.13 |
d = x_c < 1.0 ? x_c*x - (c+.5) : (double)(x - xcent); |
136 |
greg |
2.7 |
if (d < -0.5) continue; |
137 |
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if (d >= 0.5) break; |
138 |
greg |
1.1 |
wsum++; |
139 |
greg |
2.12 |
addcolor(csum, scan[x+offs]); |
140 |
greg |
1.1 |
} |
141 |
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} |
142 |
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if (wsum > 1) |
143 |
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scalecolor(csum, 1.0/wsum); |
144 |
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} |
145 |
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146 |
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147 |
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dogauss(csum, xcent, ycent, c, r) /* gaussian filter */ |
148 |
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COLOR csum; |
149 |
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int xcent, ycent; |
150 |
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int c, r; |
151 |
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{ |
152 |
greg |
2.6 |
double dy, dx, weight, wsum; |
153 |
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COLOR ctmp; |
154 |
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int y; |
155 |
greg |
2.12 |
register int x, offs; |
156 |
greg |
2.2 |
register COLOR *scan; |
157 |
greg |
1.1 |
|
158 |
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wsum = FTINY; |
159 |
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setcolor(csum, 0.0, 0.0, 0.0); |
160 |
greg |
1.2 |
for (y = ycent-yrad; y <= ycent+yrad; y++) { |
161 |
greg |
2.4 |
if (y < 0) continue; |
162 |
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if (y >= yres) break; |
163 |
greg |
1.2 |
dy = (y_r*(y+.5) - (r+.5))/rad; |
164 |
greg |
1.1 |
scan = scanin[y%barsize]; |
165 |
greg |
1.2 |
for (x = xcent-xrad; x <= xcent+xrad; x++) { |
166 |
greg |
2.12 |
offs = x < 0 ? xres : x >= xres ? -xres : 0; |
167 |
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if (offs && !wrapfilt) |
168 |
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continue; |
169 |
greg |
1.2 |
dx = (x_c*(x+.5) - (c+.5))/rad; |
170 |
greg |
2.6 |
weight = lookgauss(dx*dx + dy*dy); |
171 |
greg |
1.1 |
wsum += weight; |
172 |
greg |
2.12 |
copycolor(ctmp, scan[x+offs]); |
173 |
greg |
1.1 |
scalecolor(ctmp, weight); |
174 |
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addcolor(csum, ctmp); |
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} |
176 |
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} |
177 |
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scalecolor(csum, 1.0/wsum); |
178 |
greg |
2.7 |
} |
179 |
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180 |
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181 |
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dothresh(xcent, ycent, ccent, rcent) /* gaussian threshold filter */ |
182 |
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int xcent, ycent; |
183 |
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int ccent, rcent; |
184 |
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{ |
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double d; |
186 |
greg |
2.12 |
int r, y, offs; |
187 |
greg |
2.7 |
register int c, x; |
188 |
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register float *gscan; |
189 |
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/* compute ring sums */ |
190 |
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bzero((char *)ringsum, (orad+1)*sizeof(float)); |
191 |
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bzero((char *)ringwt, (orad+1)*sizeof(short)); |
192 |
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for (r = -orad; r <= orad; r++) { |
193 |
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if (rcent+r < 0) continue; |
194 |
greg |
2.8 |
if (rcent+r >= nrows) break; |
195 |
greg |
2.7 |
gscan = greybar[(rcent+r)%obarsize]; |
196 |
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for (c = -orad; c <= orad; c++) { |
197 |
greg |
2.12 |
offs = ccent+c < 0 ? ncols : |
198 |
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ccent+c >= ncols ? -ncols : 0; |
199 |
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if (offs && !wrapfilt) |
200 |
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continue; |
201 |
greg |
2.7 |
x = ringndx[c*c + r*r]; |
202 |
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if (x < 0) continue; |
203 |
greg |
2.12 |
ringsum[x] += gscan[ccent+c+offs]; |
204 |
greg |
2.7 |
ringwt[x]++; |
205 |
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} |
206 |
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} |
207 |
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/* filter each subpixel */ |
208 |
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for (y = ycent+1-ybrad; y <= ycent+ybrad; y++) { |
209 |
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if (y < 0) continue; |
210 |
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if (y >= yres) break; |
211 |
greg |
2.13 |
d = y_r < 1.0 ? y_r*y - (rcent+.5) : (double)(y - ycent); |
212 |
greg |
2.7 |
if (d < -0.5) continue; |
213 |
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if (d >= 0.5) break; |
214 |
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for (x = xcent+1-xbrad; x <= xcent+xbrad; x++) { |
215 |
greg |
2.12 |
offs = x < 0 ? xres : x >= xres ? -xres : 0; |
216 |
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if (offs && !wrapfilt) |
217 |
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continue; |
218 |
greg |
2.13 |
d = x_c < 1.0 ? x_c*x - (ccent+.5) : (double)(x - xcent); |
219 |
greg |
2.7 |
if (d < -0.5) continue; |
220 |
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if (d >= 0.5) break; |
221 |
greg |
2.12 |
sumans(x, y, rcent, ccent, |
222 |
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pickfilt((*ourbright)(scanin[y%barsize][x+offs]))); |
223 |
greg |
2.7 |
} |
224 |
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} |
225 |
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} |
226 |
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227 |
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228 |
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double |
229 |
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pickfilt(p0) /* find filter multiplier for p0 */ |
230 |
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double p0; |
231 |
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{ |
232 |
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double m = 1.0; |
233 |
greg |
2.10 |
double t, num, denom, avg, wsum; |
234 |
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double mlimit[2]; |
235 |
greg |
2.9 |
int ilimit = 4/TEPS; |
236 |
greg |
2.7 |
register int i; |
237 |
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/* iterative search for m */ |
238 |
greg |
2.11 |
mlimit[0] = 1.0; mlimit[1] = orad/rad/CHECKRAD; |
239 |
greg |
2.7 |
do { |
240 |
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/* compute grey weighted average */ |
241 |
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i = 1.25*CHECKRAD*rad*m + .5; |
242 |
greg |
2.8 |
if (i > orad) i = orad; |
243 |
greg |
2.7 |
avg = wsum = 0.0; |
244 |
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while (i--) { |
245 |
greg |
2.8 |
t = (i+.5)/(m*rad); |
246 |
greg |
2.7 |
t = lookgauss(t*t); |
247 |
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avg += t*ringsum[i]; |
248 |
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wsum += t*ringwt[i]; |
249 |
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} |
250 |
greg |
2.10 |
if (avg < 1e-20) /* zero inclusive average */ |
251 |
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return(1.0); |
252 |
greg |
2.7 |
avg /= wsum; |
253 |
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/* check threshold */ |
254 |
greg |
2.10 |
denom = m*m/gausstable[0] - p0/avg; |
255 |
greg |
2.11 |
if (denom <= FTINY) { /* zero exclusive average */ |
256 |
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if (m >= mlimit[1]-REPS) |
257 |
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break; |
258 |
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m = mlimit[1]; |
259 |
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continue; |
260 |
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} |
261 |
greg |
2.10 |
num = p0/avg - 1.0; |
262 |
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if (num < 0.0) num = -num; |
263 |
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t = num/denom; |
264 |
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if (t <= thresh) { |
265 |
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if (m <= mlimit[0]+REPS || (thresh-t)/thresh <= TEPS) |
266 |
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break; |
267 |
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} else { |
268 |
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if (m >= mlimit[1]-REPS || (t-thresh)/thresh <= TEPS) |
269 |
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break; |
270 |
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} |
271 |
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t = m; /* remember current m */ |
272 |
greg |
2.7 |
/* next guesstimate */ |
273 |
greg |
2.10 |
m = sqrt(gausstable[0]*(num/thresh + p0/avg)); |
274 |
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if (m < t) { /* bound it */ |
275 |
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if (m <= mlimit[0]+FTINY) |
276 |
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m = 0.5*(mlimit[0] + t); |
277 |
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mlimit[1] = t; |
278 |
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} else { |
279 |
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if (m >= mlimit[1]-FTINY) |
280 |
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m = 0.5*(mlimit[1] + t); |
281 |
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mlimit[0] = t; |
282 |
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} |
283 |
greg |
2.7 |
} while (--ilimit > 0); |
284 |
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return(m); |
285 |
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} |
286 |
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287 |
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288 |
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sumans(px, py, rcent, ccent, m) /* sum input pixel to output */ |
289 |
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int px, py; |
290 |
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int rcent, ccent; |
291 |
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double m; |
292 |
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{ |
293 |
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double dy, dx; |
294 |
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COLOR pval, ctmp; |
295 |
greg |
2.12 |
int ksiz, r, offs; |
296 |
greg |
2.7 |
double pc, pr, norm; |
297 |
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register int i, c; |
298 |
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register COLOR *scan; |
299 |
greg |
2.12 |
/* |
300 |
|
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* This normalization method fails at the picture borders because |
301 |
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* a different number of input pixels contribute there. |
302 |
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*/ |
303 |
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scan = scanin[py%barsize] + (px < 0 ? xres : px >= xres ? -xres : 0); |
304 |
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copycolor(pval, scan[px]); |
305 |
greg |
2.7 |
pc = x_c*(px+.5); |
306 |
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pr = y_r*(py+.5); |
307 |
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ksiz = CHECKRAD*m*rad + 1; |
308 |
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if (ksiz > orad) ksiz = orad; |
309 |
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/* compute normalization */ |
310 |
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norm = 0.0; |
311 |
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i = 0; |
312 |
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for (r = rcent-ksiz; r <= rcent+ksiz; r++) { |
313 |
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if (r < 0) continue; |
314 |
|
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if (r >= nrows) break; |
315 |
|
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dy = (pr - (r+.5))/(m*rad); |
316 |
|
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for (c = ccent-ksiz; c <= ccent+ksiz; c++) { |
317 |
greg |
2.12 |
if (!wrapfilt) { |
318 |
|
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if (c < 0) continue; |
319 |
|
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if (c >= ncols) break; |
320 |
|
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} |
321 |
greg |
2.7 |
dx = (pc - (c+.5))/(m*rad); |
322 |
|
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norm += warr[i++] = lookgauss(dx*dx + dy*dy); |
323 |
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} |
324 |
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} |
325 |
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norm = 1.0/norm; |
326 |
|
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if (x_c < 1.0) norm *= x_c; |
327 |
|
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if (y_r < 1.0) norm *= y_r; |
328 |
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/* sum pixels */ |
329 |
|
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i = 0; |
330 |
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for (r = rcent-ksiz; r <= rcent+ksiz; r++) { |
331 |
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if (r < 0) continue; |
332 |
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if (r >= nrows) break; |
333 |
|
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scan = scoutbar[r%obarsize]; |
334 |
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for (c = ccent-ksiz; c <= ccent+ksiz; c++) { |
335 |
greg |
2.12 |
offs = c < 0 ? ncols : c >= ncols ? -ncols : 0; |
336 |
|
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if (offs && !wrapfilt) |
337 |
|
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continue; |
338 |
greg |
2.7 |
copycolor(ctmp, pval); |
339 |
|
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dx = norm*warr[i++]; |
340 |
|
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scalecolor(ctmp, dx); |
341 |
greg |
2.12 |
addcolor(scan[c+offs], ctmp); |
342 |
greg |
2.7 |
} |
343 |
|
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} |
344 |
greg |
1.1 |
} |