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comparison Meerwald/wm_bruyn_d.c @ 0:be303a3f5ea8

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author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Sun, 12 Aug 2007 13:14:34 +0200
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children f83ef905a63d
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-1:000000000000 0:be303a3f5ea8
1 #include "wm.h"
2 #include "signature.h"
3 #include "coord.h"
4 #include "gray.h"
5 #include "sort.h"
6 #include "bruyn_common.h"
7 #include "pgm.h"
8
9 char *progname;
10
11 // prints out program's parameters
12 void usage(void) {
13 fprintf(stderr, "usage: %s [-b n] [-h] [-k] [-n n] [-o file] [-pP n] [-q n] [-tT n] [-v n] -s file file\n", progname);
14 fprintf(stderr, "\t-b n\t\tblock size\n");
15 fprintf(stderr, "\t-h\t\tprint usage\n");
16 fprintf(stderr, "\t-k\t\tdisable block skipping\n");
17 fprintf(stderr, "\t-n n\t\tnumber of signature bits to detect\n");
18 fprintf(stderr, "\t-o file\t\textracted signature file\n");
19 fprintf(stderr, "\t-p n\t\tpattern type for zone 1\n");
20 fprintf(stderr, "\t-P n\t\tpattern type for zone 2\n");
21 fprintf(stderr, "\t-q n\t\tsignature strength\n");
22 fprintf(stderr, "\t-s file\t\tembedded signature\n");
23 fprintf(stderr, "\t-t n\t\tthreshold for noise\n");
24 fprintf(stderr, "\t-T n\t\tthreshold for slope\n");
25 fprintf(stderr, "\t-v n\t\tverbosity level\n");
26 exit(0);
27 }
28
29 int main(int argc, char *argv[]) {
30 FILE *in = stdin;
31 FILE *out = stdout;
32 FILE *sig = NULL;
33
34 gray** image;
35 gray **block;
36 gray **zone;
37 gray **category1, **category2;
38 gray maxval;
39 double *slope;
40 int rows, cols, colors, format;
41 int c;
42 int i, j;
43 int r;
44 int n;
45 int col, row;
46 int bwidth, bheight;
47 int n_block;
48
49 char signature_name[MAXPATHLEN];
50 char input_name[MAXPATHLEN] = "(stdin)";
51 char output_name[MAXPATHLEN] = "(stdout)";
52
53 double quality = 0.0;
54 double threshold_noise = 0.0;
55 double threshold_slope = 0.0;
56 int pattern1 = 0;
57 int pattern2 = 0;
58 int blocksize = 0;
59 int seed;
60
61 int verbose = 0;
62 int skipping = 0;
63
64 struct coords *coords;
65
66 progname = argv[0];
67
68 pgm_init(&argc, argv); wm_init2();
69
70 // parse command line and set options
71 while ((c = getopt(argc, argv, "b:h?n:o:p:P:q:s:t:T:v:k")) != EOF) {
72 switch (c) {
73 case 'h':
74 case '?':
75 usage();
76 break;
77 case 'k':
78 skipping = 1;
79 break;
80 case 'n':
81 nbit_signature = atoi(optarg);
82 if (nbit_signature <= 0 || nbit_signature > NBITSIGNATURE) {
83 fprintf(stderr, "%s: invalid signature length %d\n", progname, nbit_signature);
84 exit(1);
85 }
86 break;
87 case 'o':
88 if ((out = fopen(optarg, "wb")) == NULL) {
89 fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg);
90 exit(1);
91 }
92 strcpy(output_name, optarg);
93 break;
94 case 'p':
95 pattern1 = atoi(optarg);
96 if (pattern1 <= 0 || pattern1 > NPATTERN) {
97 fprintf(stderr, "%s: pattern type out of range\n", progname);
98 exit(1);
99 }
100 break;
101 case 'P':
102 pattern2 = atoi(optarg);
103 if (pattern2 <= 0 || pattern2 > 3) {
104 fprintf(stderr, "%s: pattern type out of range\n", progname);
105 exit(1);
106 }
107 break;
108 case 'q':
109 quality = atof(optarg);
110 if (quality <= 0) {
111 fprintf(stderr, "%s: quality factor %f out of range\n", progname, quality);
112 }
113 break;
114 case 's':
115 if ((sig = fopen(optarg, "r")) == NULL) {
116 fprintf(stderr, "%s: unable to open signature file %s\n", progname, optarg);
117 exit(1);
118 }
119 strcpy(signature_name, optarg);
120 break;
121 case 't':
122 threshold_noise = atof(optarg);
123 if (threshold_noise <= 0) {
124 fprintf(stderr, "%s: noise threshold %f out of range\n", progname, threshold_noise);
125 }
126 break;
127 case 'T':
128 threshold_slope = atof(optarg);
129 if (threshold_slope <= 0) {
130 fprintf(stderr, "%s: slope threshold %f out of range\n", progname, threshold_slope);
131 }
132 break;
133 case 'v':
134 verbose = atoi(optarg);
135 if (verbose < 0) {
136 fprintf(stderr, "%s: verbosity level %d out of range\n",progname, verbose);
137 exit(1);
138 }
139 break;
140 }
141 }
142
143 argc -= optind;
144 argv += optind;
145
146 if (argc > 1) {
147 usage();
148 exit(1);
149 }
150
151 // open input image file or read from stdin
152 if (argc == 1 && *argv[0] != '-')
153 if ((in = fopen(argv[0], "rb")) == NULL) {
154 fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
155 exit(1);
156 }
157 else
158 strcpy(input_name, argv[0]);
159
160 // read signature file and set options
161 // command line options override signature file options
162 if (sig) {
163 char line[128];
164 fgets(line, sizeof(line), sig);
165 if (strspn(line, "BRSG") >= 4) {
166 if (nbit_signature == 0)
167 fscanf(sig, "%d\n", &nbit_signature);
168 else
169 fscanf(sig, "%*d\n");
170 if (skipping == 0)
171 fscanf(sig, "%d\n", &skipping);
172 else
173 fscanf(sig, "%*d\n");
174 if (pattern1 == 0)
175 fscanf(sig, "%d\n", &pattern1);
176 else
177 fscanf(sig, "%*d\n");
178 if (pattern2 == 0)
179 fscanf(sig, "%d\n", &pattern2);
180 else
181 fscanf(sig, "%*d\n");
182 if (quality == 0.0)
183 fscanf(sig, "%lf\n", &quality);
184 else
185 fscanf(sig, "%*lf\n");
186 if (threshold_noise == 0.0)
187 fscanf(sig, "%lf\n", &threshold_noise);
188 else
189 fscanf(sig, "%*lf\n");
190 if (threshold_slope == 0.0)
191 fscanf(sig, "%lf\n", &threshold_slope);
192 else
193 fscanf(sig, "%*lf\n");
194 if (blocksize == 0)
195 fscanf(sig, "%d\n", &blocksize);
196 else
197 fscanf(sig, "%*d\n");
198 fscanf(sig, "%d\n", &seed);
199 srandom(seed);
200 n_signature = NBITSTOBYTES(nbit_signature);
201 fread(signature, sizeof(char), n_signature, sig);
202 init_signature_bits();
203 fscanf(sig, "\n");
204 }
205 else {
206 fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name);
207 exit(1);
208 }
209 fclose(sig);
210 }
211 else {
212 fprintf(stderr, "%s: signature file not specified, use -s file option\n", progname);
213 exit(1);
214 }
215
216 if (pattern1 <= 0 || pattern2 <= 0 || pattern1 > NPATTERN || pattern2 > NPATTERN) {
217 fprintf(stderr, "%s: invalid pattern type specified\n");
218 exit(1);
219 }
220
221 // read dimensions of input image file
222 pgm_readpgminit(in, &cols, &rows, &maxval, &format);
223
224 // see if we can extract all signature bits
225 // we want at least half of the blocks untouched
226 if (((rows / blocksize) * (cols / blocksize)) < nbit_signature / 2) {
227 fprintf(stderr, "%s: image not large enough to contain %d bits of signature\n", progname, nbit_signature);
228 exit(1);
229 }
230 n_block = blocksize * blocksize;
231
232 // allocate structure to remember which blocks we already touched,
233 // allow plenty of room to skip over blocks
234 if ((coords = alloc_coords(nbit_signature * 2)) == NULL) {
235 fprintf(stderr, "%s: unable to allocate memory\n", progname);
236 exit(1);
237 }
238
239 // read in input image file
240 image = pgm_allocarray(cols, rows);
241 for (row = 0; row < rows; row++)
242 pgm_readpgmrow(in, image[row], cols, maxval, format);
243
244 fclose(in);
245
246 row = 0;
247 col = 0;
248
249 // allocate memory for one block
250 block = alloc_grays(blocksize, blocksize);
251
252 // allocate memory for zone classification
253 zone = alloc_grays(blocksize, blocksize);
254
255 // allocate memory for category classification
256 category1 = alloc_grays(blocksize, blocksize);
257 category2 = alloc_grays(blocksize, blocksize);
258
259 // set up category classification array according to
260 // pattern type parameter
261 for (i = 0; i < blocksize; i++)
262 for (j = 0; j < blocksize; j++) {
263 category1[j][i] = lookup_pattern(pattern1, i, j);
264 category2[j][i] = lookup_pattern(pattern2, i, j);
265 }
266
267 // allocate memory for slope calculation
268 slope = malloc(sizeof(double) * n_block);
269
270 fprintf(out, "BRWM\n");
271 fprintf(out, "%d\n", nbit_signature);
272
273 // extract all the signature bits, one by one
274 n = 0;
275 while (n < nbit_signature) {
276 int xb;
277 int yb;
278 int blocktype;
279 double smax;
280 int alpha, beta_minus, beta_plus;
281 double mean_1A, mean_1B, mean_2A, mean_2B, mean_1, mean_2;
282 double mean__1A, mean__1B, mean__2A, mean__2B;
283 int n_1A, n_1B, n_2A, n_2B, n_1, n_2;
284 double sigma, sigma_1, sigma_2;
285 int zone1_ok, zone2_ok;
286
287 // find an unused block randomly, depending on seed
288 do {
289 xb = random() % (cols / blocksize);
290 yb = random() % (rows / blocksize);
291 } while (add_coord(coords, xb, yb) < 0);
292
293 // copy image block
294 copy_grays_to_block(block, image, xb * blocksize, yb * blocksize, blocksize, blocksize);
295
296 if (verbose > 0)
297 fprintf(stderr, "detecting bit #%d in block at (%d/%d)\n", n, xb * blocksize, yb * blocksize);
298
299 // sort luminance values in block to represent increasing function F
300 sort_grays(block[0], n_block);
301
302 // calculate slopes of F and determine smax, the max. slope of F
303 // the index where smax occures is called alpha
304 alpha = 0;
305 smax = 0.0;
306 for (i = 0; i < n_block - 1; i++) {
307 slope[i] = block[0][i + 1] - block[0][i];
308 if (slope[i] > smax) {
309 smax = slope[i];
310 alpha = i;
311 }
312 }
313 slope[n_block - 1] = 0;
314
315 // block type classification
316 blocktype = BLOCKTYPE_UNKNOWN;
317
318 if (smax < threshold_noise) {
319 // block has noise contrast
320 beta_minus = beta_plus = alpha;
321 blocktype = BLOCKTYPE_NOISE;
322 }
323 else {
324 // block has progressive or hard contrast, let's find out...
325
326 beta_minus = alpha - 1;
327 while (beta_minus >= 0 && smax - slope[beta_minus] <= threshold_slope)
328 beta_minus--;
329
330 beta_plus = alpha + 1;
331 while (beta_plus < n_block && smax - slope[beta_plus] <= threshold_slope)
332 beta_plus++;
333
334 if (beta_minus + 1 == alpha && beta_plus - 1 == alpha)
335 blocktype = BLOCKTYPE_HARD;
336 else
337 blocktype = BLOCKTYPE_PROGRESSIVE;
338 }
339
340 if (verbose > 1) {
341 fprintf(stderr, "blocktype: %d\n", blocktype);
342 fprintf(stderr, "Smax = %lf, alpha = %d, beta- = %d, beta+ = %d\n", smax, alpha, beta_minus, beta_plus);
343 }
344
345 // block pixel classification
346 for (i = 0; i < blocksize; i++)
347 for (j = 0; j < blocksize; j++) {
348 gray pixel = image[yb * blocksize + j][xb * blocksize + i];
349 zone[j][i] = ZONE_VOID;
350 switch (blocktype) {
351 case BLOCKTYPE_PROGRESSIVE:
352 case BLOCKTYPE_HARD:
353 if (pixel < block[0][beta_minus])
354 zone[j][i] = ZONE_1;
355 else if (pixel > block[0][beta_plus])
356 zone[j][i] = ZONE_2;
357 break;
358 case BLOCKTYPE_NOISE:
359 if (pixel < block[0][n_block / 2])
360 zone[j][i] = ZONE_1;
361 else if (pixel > block[0][n_block / 2])
362 zone[j][i] = ZONE_2;
363 break;
364 default:
365 fprintf(stderr, "%s: invalid block type\n", progname);
366 break;
367 }
368 }
369
370 // calculate mean values for zone/categories
371 mean_1A = mean_1B = mean_2A = mean_2B = mean_1 = mean_2 = 0.0;
372 n_1A = n_1B = n_2A = n_2B = n_1 = n_2 = 0;
373 for (i = 0; i < blocksize; i++)
374 for (j = 0; j < blocksize; j++) {
375 gray pixel = image[yb * blocksize + j][xb * blocksize + i];
376 int pixel_zone = zone[j][i];
377 int pixel_category = CATEGORY_VOID;
378 if (pixel_zone == ZONE_1)
379 pixel_category = category1[j][i];
380 else if (pixel_zone == ZONE_2)
381 pixel_category = category2[j][i];
382
383 switch (pixel_zone | pixel_category) {
384 case CLASSIFICATION_1A:
385 n_1++;
386 n_1A++;
387 mean_1A += pixel;
388 mean_1 += pixel;
389 break;
390 case CLASSIFICATION_1B:
391 n_1++;
392 n_1B++;
393 mean_1B += pixel;
394 mean_1 += pixel;
395 break;
396 case CLASSIFICATION_2A:
397 n_2++;
398 n_2A++;
399 mean_2A += pixel;
400 mean_2 += pixel;
401 break;
402 case CLASSIFICATION_2B:
403 n_2++;
404 n_2B++;
405 mean_2B += pixel;
406 mean_2 += pixel;
407 break;
408 }
409 }
410
411 if (n_1 && n_1A && n_1B) {
412 mean_1 /= (double) n_1;
413 mean_1A /= (double) n_1A;
414 mean_1B /= (double) n_1B;
415 zone1_ok = 1;
416 }
417 else {
418 mean_1 = mean_1A = mean_1B = 0.0;
419 zone1_ok = 0;
420 if (verbose > 0)
421 fprintf(stderr, "zone 1 unusable\n");
422 }
423
424 if (n_2 && n_2A && n_2B) {
425 mean_2 /= (double) n_2;
426 mean_2A /= (double) n_2A;
427 mean_2B /= (double) n_2B;
428 zone2_ok = 1;
429 }
430 else {
431 mean_2 = mean_2A = mean_2B = 0.0;
432 zone2_ok = 0;
433 if (verbose > 0)
434 fprintf(stderr, "zone 2 unusable\n");
435 }
436
437 // bit extraction
438 if (zone1_ok && zone2_ok) {
439 sigma_1 = mean_1A - mean_1B;
440 sigma_2 = mean_2A - mean_2B;
441
442 if (verbose > 2) {
443 fprintf(stderr, "m_1A = %lf, m_1B = %lf\n", mean_1A, mean_1B);
444 fprintf(stderr, "m_2A = %lf, m_2B = %lf\n", mean_2A, mean_2B);
445 fprintf(stderr, "sigma1 = %lf, sigma2 = %lf\n", sigma_1, sigma_2);
446 }
447
448 #define EPSILON 0.001
449 if (fabs(sigma_1 * sigma_2) < EPSILON) {
450 // case 3
451 sigma = MAX(fabs(sigma_1), fabs(sigma_2));
452 set_signature_bit(n, sigma > 0.0);
453 if (verbose > 0)
454 fprintf(stderr, "case 3, bit #%d = %d\n", n, sigma > 0.0);
455 }
456 else if (sigma_1 * sigma_2 > 0.0) {
457 // case 1
458 set_signature_bit(n, sigma_1 > 0.0);
459 if (verbose > 0)
460 fprintf(stderr, "case 1, bit #%d = %d\n", n, sigma_1 > 0.0);
461 }
462 else if (sigma_1 * sigma_2 < 0.0) {
463 // case 2
464 sigma = (double) (n_1A + n_1B) * sigma_1 + (double) (n_2A + n_2B) * sigma_2;
465 set_signature_bit(n, sigma > 0.0);
466 if (verbose > 0)
467 fprintf(stderr, "case 2, bit #%d = %d\n", n, sigma > 0.0);
468 }
469 }
470 else if (zone1_ok) {
471 set_signature_bit(n, mean_1A > mean_1B);
472 if (verbose > 0)
473 fprintf(stderr, "case 4, bit #%d = %d\n", n, mean_1A > mean_1B);
474 }
475 else if (zone2_ok) {
476 set_signature_bit(n, mean_2A > mean_2B);
477 if (verbose > 0)
478 fprintf(stderr, "case 5, bit #%d = %d\n", n, mean_2A > mean_2B);
479 }
480 else {
481 // pathological case - can it ever happen?
482 if (verbose > 0)
483 fprintf(stderr, "block skipped\n");
484 if (!skipping) continue;
485 }
486
487 n++;
488 }
489
490 free_grays(category2);
491 free_grays(category1);
492 free_grays(zone);
493 free_grays(block);
494
495 // write extracted signature
496
497 fwrite(signature, sizeof(char), n_signature, out);
498 fclose(out);
499
500 pgm_freearray(image, rows);
501
502 exit(0);
503 }

Repositories maintained by Peter Meerwald, pmeerw@pmeerw.net.